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http://www.webmedcentral.com/images/Header_Logo.giftext/html2010-09-25T08:17:43+01:00http://www.webmedcentral.com/Mr. Ram Prakash PrajapatDendrimer: A Polymer of 21st Century
http://www.webmedcentral.com/article_view/745
A dendrimer is generally described as a macromolecule, which is characterized by its highly branched 3D structure that provides a high degree of surface functionality and versatility. Dendrimers have often been refered to as the “Polymers of the 21st century”. The unique architectural design of dendrimers, high degree of branching, multivalency, globular structure and well-defined molecular weight, clearly distinguishes these as unique and optimum nanocarriers in medical applications such as drug delivery, gene transfection, tumor therapy and diagnostics etc. An increasingly large number of drugs being developed today facing problems of poor solubility, bioavailability and permeability, dendrimers can work as a useful tool for optimizing drug delivery of such problematic drugs. Also the problem of biocompatibility and toxicity can be overcome by careful surface engineering. Recent successes in simplifying and optimizing the synthesis of dendrimers provide a large variety of structures with reduced cost of their production. Also as research progresses, newer applications of dendrimers will emerge and the future should witness an increasing numbers of commercialized dendrimer based drug delivery systems.
A dendrimer (from Greek dendra for tree) is a highly branched synthetic polymer and consists of a core where a monomer unit is attached, leading to a monodisperse, tree-like, star-shaped or generational structure with precise molecular weights and diameters in the 2 to 10 nm range size . Production of dendrimer requires a high level of synthetic control, which can be achieved via stepwise reactions, building the dendrimer up one monomer layer (or "generation") at a time.
The first monomer unit, in this example, has a functionality of three with one reactive site attached to the core or focal point and the other two making up a branching unit. This is considered the first generation or G1. The branching unit is then reacted with further monomer to produce G2 and a molecule with four end groups. [1-6]text/html2012-11-06T19:48:19+01:00http://www.webmedcentral.com/Mr. Rajeev K SinglaParmeliaceae- An Important Family of Lichens with Medicinal Importance
http://www.webmedcentral.com/article_view/3807
Life always coexists with disease, death and decay. To sustain a healthy and happy life, man has been applying his knowledge to discover the remedies for prevention and treatment of diseases since the human civilisation began. Plants were the natural sources mainly on which people totally depended to fight against diseases when there was no alternative.
The Parmeliaceae is the most diverse and large family of the order Lecanoromycetes. It has 87 genera which have more than 2000 species. It is considered as the largest family of fungi which forms lichens (These are the fungi which has a symbiotic relationship with algae). The main genera in the family are: Xanthoparmelia have more than 800 species, Usnea with more than 500 species, Parmotrema with more than 350 species and Hypotrachyna with more than 190 species.
Most of the members in the family have a symbiotic relationship with algae. The majority of species in Parmeliaceae have a fruticose, subfruticose or foliose form of growth. The huge variation in morphology and complexity is observed in members of this group. The family can be found in a wide range of climatic regions and habitats and has a cosmopolitan distribution. They can be found everywhere from alpine rocks to roadside pavement, from subshrubs in the arctic tundra to tropical rainforest trees. Members of this family can be found in almost all kinds of terrestrial environments.
Characteristics of Structure
• Thallus
• Apothecia
• Spores
Thallus
Parmeliaceae thallus is mostly fruticose, foliose or subfruticose but also can be caespitose, umblicate, peltate, subcrustose or crustose. They can be seen in different colours from green to yellow, whitish to grey, or brown to black. Many genera are lobe forming. Species are usually rhizinate on the lower surface occasionally with rhizohyphae, hypothallus, or holdfasts. Epicortex the upper surface may have non-pored or pored surface. Medulla is often loosely woven but sometimes it is solid. Lower surface is naked in only some genera for example Menegazzia, Usnea and Hypogymnia. (literature at the burkes luck lichen trail, supplied by professor dirk wessels of the university of the north)
Apothecia
Apothecia are lecanorine and they are produced along the margin or lamina and pedicellate to sessile and sometimes sunken. Thalline exciple is concolourous with the thallus. Asci are amyloid along with the majority of species having 8 spores per ascus, few species have many spores and many species of Menegazzia have 2 spores per ascus.
Spores
Ascospores are often small, simple and hyaline. Conidia usually arise laterally from the joints of conidiogenous hyphae (Parmelia type), but arise terminally from these joints in a small number of species (Psora type). The conidia can have a wide range of shapes from bacilliform to fusiform, cylindrical, bifusiform, curved, unciform, sublageniform or filiform. Pycnidia are rarely emergent from the upper cortex or immersed are produced along the margins or lamina, pyriform shaped and can be seen from black to dark-brown in colour.
This family mostly contain lichens. Lichens are fungi which forms a symbiotic relationship with green alga or blue green alga (cyanobacterium) or both. These can be found almost in all type of habitats and substrates.
Linnaeus recognised and classified nearly 80 species in 1753. Erik Acharius called the father of lichenology was the first scientist who seriously studied lichens and also described many new species but Schwendener was the one who discovered the dual nature of lichens in 1869 before that the green structures within lichen were believed to be gonads but were actually green alga .The estimated number of lichen species range from 13,000 to 30,000 worldwide.
The majority of the lichens belong to family Ascomycota in which spores are produced inside asci. The evolution of lichens is very old; the oldest evidence of fossil lichen is from the Rhyne chert formation in Scotland which dates back to 400 million years ago.
In the lichen symbiosis, fungal partner is called mycobiont and algal partner is called photobiont. The mycobiont protects photobiont against dehydration and harmful UV radiations which enables the algal partner to survive in habitats which would be generally inaccessible. The mycobiont is also responsible for the shape and sexual reproductive structures of lichens. The photobiont plays its role in carrying out photosynthesis and producing carbohydrates which are metabolised by fungus. The characteristic unique secondary metabolite of lichen is actually produced by the mycobionts. If blue green alga is partner in symbiosis then the mycobiont can obtain nitrogen compounds because this alga is capable of fixing atmospheric nitrogen. Generally nutrients and water are taken directly through the surface of the lichen because of this they can even survive in low rainfall or moist regions.
Lichens are of different shapes and forms .They typically grows on bark, rock and soil but they can also grow on leaves, roof tiles, asphalt, metal surfaces and many other surfaces. Lichen body which is called thallus is composed of upper cortex containing tightly packed fungal hyphae below which is the photosynthetic algal layer. Below this layer is there is loosely woven cottony layer of fungal hyphae called medulla where most of the secondary metabolites are deposited as crystals. The fungal layer determines the secondary metabolites and is useful for identification.
Compared to plants, lichens grow very slowly ranging from less than a millimetre per year in case of micro-lichens to almost 10 cm per year in case of macro-lichens. Lichens are generally classified based on their growth form which is artificial classification system but used mainly for identifying lichens.
The most common categories are crustose, fruticose and foliose. Crustose lichens have a thallus which forms a blotch on the substratum on which it grows and is very difficult to remove without cutting a part of it. Fruticose lichens are bushy, pendulous or upright position. They are highly branched which helps in increasing the surface area. Foliose lichens appear flattened with a distinguishable upper and lower surface and they can be easily removed using a knife.
In Australia approximately more than 3500 species of lichens have been recorded and more than 35% of these are regarded as endemic (McCarthy 2009).They are greatest in numbers in Queensland (1796 species) which also contains endemic (260species), followed by NSW (1498 species) which contain 112 endemic species, then by Tasmania (1063 species) which contains 102 endemic species.
Economic importance of Lichens
Lichen is derived from the Greek word ‘Leprous’ and refers to medicine used for treatment of skin diseases because of their appearance as peeling skin. Lichens are used as source of food in many regions. For example cetraria islandica was used as food in Northern Europe and was cooked as porridge, soup, bread, salad and pudding. Some lichens known as Earth Flowers have a strong and distinct odour so they are smoked along with tobacco used in summer dances (Curtin, LSM. 1984).
Lichens such as Bryoria fremoontii were mostly used as food in times of famine in North America so they were called famine food. The extracts from lichens are used to dye wool and for production of ‘Harris Tweed’ of Scotland. They are also used in the manufacture of ‘moss’ and ‘leather’ fragrances in perfumes and some type of soaps (Richardson, D. H. S. 1974). In China, lichens are used as food (Lobaria isidiophra, L.yoshimurae) and also as health promoting tea (Thamnolia subuliformis, Lethariella cashmeriana).
Medicinal importance of Lichens
The metabolites (mainly secondary) produced by lichen exerts wide range of medicinal and biological properties like antimycobacterial, antiproliferative, antiviral, antibiotic, anti-inflammatory, cytotoxic, analgesic and antipyretic effects. Though their potential is known but they have not been explored fully (Muller, 2002).The secondary metabolites are the main compounds that are utilised for medicinal purposes (Boustie and Grube, 2005).
According to estimation more than half of the lichens have antibiotic property (Sharnoff, 1997). Usnic acid extracted from many lichens demonstrated wide spectrum antibiotic activity (Shibamoto and Wei, 1984, Rowe et al. 1991). Vulpinic acid exhibited mild antibiotic activity (Lauterwein et al.1995). These acids inhibited the growth of Bacillus subtilis, Staphylococcus aureus and Bacillus magaterium which are gram positive but did not have any effect on Escherichia coli which is gram negative (Lawrey, 1986). Alectosaementin, alectoronic acid and physodic acid were isolated from the alcoholic extract exhibited antimicrobial activity (Gollapudi et al. 1994).
The extract from acetone, chloroform, diethyl ether, petroleum ether and methanol of Parmelia sulcata Taylor, Parmelia sulcata exhibited antibacterial activity against Bacillus subtilis, Candida albicans and many other bacteria (Candan et al, 2007). Parietin and anthraquinone isolated from Caloplaca cerina methanol extract have demonstrated antifungal activity (Manojlovic, 2005). Phenolic constituents from lichen Parmotrema stuppeum include orsennilic acid, methyl orsenillate, lecanoric acid and atranorin exhibited antioxidant activity (Jayaprakasha and Rao, 2000).text/html2010-09-10T11:21:21+01:00http://www.webmedcentral.com/Mr. Akant Priya P SinglaCharacterization Of Mucoadhesive Tablets Of Ciprofloxacin
http://www.webmedcentral.com/article_view/586
Ciprofloxacin is a fluoroquinolones antibiotic used for the treatment of IBD and specific complication of Crohn’s disease. Ciprofloxacin inhibit M. fortuitum, M. kansaii and M. tuberculosis. Ciprofloxacin is effective for the treatment of prostatitis caused by sensitive bacteria. Oral dose in adults are 250-750mg. Plasma half life of ciprofloxacin is 3-5 hr. The short biological half-life of drug (3-5 hours) also favors development of a sustained release formulation. The present study done by using various mucoadhesive polymers for preparation of mucoadhesive tablets. Various approaches to combine hydrophilic (HPMC, SCMC, tragacanth and sodium alginate) and hydrophobic (ethyl cellulose) polymers have been made to prepare total seven formulations. Further, these formulations were subjected to different evaluation studies like content uniformity, surface pH, friability, wash-off and dissolution tests. All the tests were performed using standard methods. Results for in vitro drug release and wash-off studies suggest that the formulation (F7) containing tragacanth and HPMC has shown better mucoadhesive property. Other studies have shown satisfactory results in all seven formulations. Thus, the present investigation suggests the combination of HPMC and tragacanth, as hydrophilic polymers for preparation of Ciprofloxacin mucoadhesive tablets.text/html2010-09-12T19:16:12+01:00http://www.webmedcentral.com/Mr. Akant Priya P SinglaReview Of Biological Activities Of \" Tinospora Cordifolia \"
http://www.webmedcentral.com/article_view/606
Tinospora cordifolia is one of the constituents of several ayurvedic preparations used in general debility, dyspepsia, fever and urinary diseases. The stem is bitter, stomachic, diuretic, stimulates bile secretion, causes constipation, allays thirst, burning sensation, vomiting, enriches the blood and cures jaundice. The extract of its stem is useful in skin diseases. The root and stem of T. cordifolia are prescribed in combination with other drugs as an anti-dote to snake bite and scorpion sting Dry barks of T. cordifolia has anti-spasmodic, anti- pyretic, anti-allergic , anti-inflammatory and anti-leprotic properties.text/html2010-11-03T21:35:12+01:00http://www.webmedcentral.com/Dr. Jasmina Tonic-RibarskaNew High Performance Liquid Chromatography Method For Analysis Of Filgrastim In Pharmaceutical Formulations
http://www.webmedcentral.com/article_view/1117
Filgrastim is a human granulocyte colony-stimulating factor‚ which belongs to a family of cytokines. It is produced by recombinant DNA technology in genetically engineered Escherihia coli cells. Filgrastim has a biological action essential for proliferation and differentiation of hematopoetic and progenitor cells. Itis used for decreasing the risk of infection in cancer patients, who receive chemotherapy or a bone marrow transplant.The goal of this study was to develop and validate a simple and rapid RP-HPLC method for determination of filgrastim in protein formulations.The experiments were carried out by RP- HPLC using LiChrospherÒ WP 300 RP-18e, (150 x 4 mm i.d.) column.The HPLC system was operated at gradient mode using mobile phase composed of solvent A (0,1 % TFA in a mixture of water : acetonitril = 90:10 v/v) and solvent B ( 0.08% TFA in a mixture of water: acetonitril = 10:90 v/v). The temperature was 50°C and UV detection was set at 215 nm. The method was validated according the ICH guidelines. Under the proposed chromatographic conditions, the retention time for Filgrastim was about 25 min. Good linearity of the method was confirmed by the high value of the corelation coefficient (r2 = 0.9995), over a concentration range from 32 - 256 μg/ml. The RSD values for repeatability and inter-day precision were 0.45 % and 0.48 % , respectively. The obtained recovery values of 99.30 -101.38% indicate that the proposed method is quantitative and accurate.In conclusion, the RP-HPLC method used for determination of filgrastim complies with the requirements of the validation paremeters, justifying its purpose for routine analysis..text/html2011-09-02T16:41:24+01:00http://www.webmedcentral.com/Dr. Dinesh KumarNature: Anxiolytics in the Lap of Nature
http://www.webmedcentral.com/article_view/2140
BackgroundA large number of populations depend on traditional practitioners, who in turn are dependent on medicinal plants, to meet their primary health care needs. Today "traditional medicine," characterized by the use of herbs and other natural products, still remains a regular component of health care in the world.AimsTo explore the natural and traditional medicines in relation to anxieolyticsMethodElectronic literature searches were conducted using the following databases: AMED, Cinahl, Embase, Elsevier, Medline, PsychInfo, PubMed (all from inception to August 2004), Google scholar and many important text books. The terms used for the electronic searches were limited to important receptors and neurotransmitters present in brain which help to modulate anxiety, plants with neurological bioactivity and bioactive compounds with respective receptors and mechanism of action along with few chemical structures involved in the treatment of anxiety. ResultsSystematic review were located with the above search strategy Discussion and conclusionThe review covered all aspects of traditional medicines and revealed that a detailed study is required to explore the plants and their uses to treat serious complication of central nervous system. Nature and tradition both is wonder agent of God for the treatment of diseases. The review will pave a way for new drug search.Keywords: Anxiety, Anxiolytics, Traditional medicines, Neurotransmitters.
text/html2012-10-04T19:34:49+01:00http://www.webmedcentral.com/Dr. Giriraj T KulkarniAntimicrobial and Anti-inflammatory Activities of Bark of Four Plant Species from Indian Origin
http://www.webmedcentral.com/article_view/2010
The present study was designed to investigate antimicrobial and anti-inflammatory activities of four plant species from Indian origin. The antimicrobial activity of petroleum ether, chloroform, ethyl-acetate and methanol extracts of barks of Acacia nilotica, Berberis chitria, Terminalia paniculata and Madhuca longifolia were tested against Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus and Bacillus subtilis using agar well diffusion and micro dilution assays. In the well diffusion assay, 27 out of the 64 extracts showed good activity. Significant activity was observed in the micro dilution assay with all extracts. Highest activity against Escherichia coli and Staphylococcus aureus was observed in the ethyl acetate and methanol extracts of Berberis chitria with minimum inhibitory concentration values of 5.5 and 6.5 mg/ml, respectively. Methanolic extracts of Berberis chitria and Terminalia paniculata showed significant inhibitory effect against Staphylococcus aureus and Bacillus subtilis with minimum inhibitory concentration values 3.25 and 3.5 mg/ml. The effects of the plant extract were compared with those of Chloromphenicol and Streptomycin. For the investigation of anti-inflammatory activity of the methanol extracts of the selected plants, carrageenan induced rat hind paw edema model was employed. All the selected plant extracts exhibited significant, dose-dependent anti-inflammatory activity and produced a significant inhibition of carrageenan-induced paw edema in rats at the end of 3 h, which was comparable to the standard drug, indomethacin.text/html2012-11-23T16:35:17+01:00http://www.webmedcentral.com/Dr. Swaminathan RajanAntibiotic Sensitivity and Phenotypic Detection Of ESBL producing E.Coli Strains Causing Urinary Tract Infection In a Community Hospital, Chennai, Tamil Nadu, India.
http://www.webmedcentral.com/article_view/3840
Urinary Tract Infection (UTI) forms the largest single group of hospital acquired infections and account for about 40-50% of the total nosocomial infections. In spite of the wide spread availability of antibiotics, UTI remains to be one of the most common infectious diseases diagnosed. Further world wide data shows that there is an increasing resistance among UTI pathogens to conventional drugs. Resistance have emerged even to newer more potent antimicrobial agents. Therefore, the aim of the present study is to determine the prevalence and susceptibility of extended spectrum beta – lactamase in urinary isolates of Escherichia coli (E. coli) in a community hospital, Sundaram Medical Foundation, Chennai, South India. A total number of 562 urine samples suspicious of UTI were analyzed and it was found that 115 cultures were positive for E. coli infection. The study period ranges from March to April 2012. Antimicrobial susceptibility testing was determined to commonly used antibiotics using the modified Kirby-Bauer’s disc diffusion method. ESBL detection was done by the screening method of double disc synergy test and then confirmed by the phenotypic confirmatory test with combination disc as recommended by the Clinical Laboratory Standards Institute (CLSI) and the minimum inhibitory concentration (MIC) method using the E-test strips (AB Biodisk, Sweden). The prevalence of ESBL E. coli was 34.8%. The ESBL producing isolates were significantly resistant to Ampicillin (100%), norfloxacin (98%) and Nalidixic acid (100%) and third generation of cephalosporins (100%) as compared to non-ESBL producers. Multidrug resistance was significantly higher (63.2%) in ESBL positive isolates than non-ESBL isolates (26.3%). Knowledge of the prevalence of ESBL and resistance pattern of bacterial isolates in a geographical area will help the clinicians to formulate the guidelines for antibiotic therapy to avoid inappropriate use of extended spectrum cephalosporins. In conclusion the study of ESBL producing E. coli can be treated with beta lactamase inhibitors like Augmentin and Tazobactum / Pippercillin to some extent. As carbapenems like Imipenem and Ertapenem sensitivity is high, therefore these drugs are the only choice for the treatment of severe or life threatening infections caused by ESBL producing organisms. In order to prevent the outbreaks of this life threatening ESBL producers, certain infection control measures have to be followed. Adequate precautions have to be taken to minimize the risk of cross contamination among patients. Contact precautions by cohort patients during outbreaks and also promoting meticulous hand hygiene practices.text/html2012-08-27T16:35:12+01:00http://www.webmedcentral.com/Mr. Rajeev K SinglaInvestigation of Antimicrobial Effect of Dry Distilled Extract of Cocos Nucifera Linn Endocarp
http://www.webmedcentral.com/article_view/3671
Endocarp of C. nucifera L.(Coconut fruit), a universally acceptable waste material is the plant part for our study. Dry distilled extract, RNDS, was prepared using the special procedure adopted by our lab. It was evaluated for its antimicrobial activity using Kirby bauer agar diffusion assay technique. In gram negative- P. aeruginosa & E. coli strains were used and in gram positive – S. aureus & B. subtilis were used, while four fungal strains like A. oryzae, C. albicans, R. oligosporus and A. flavus were part of current study. Results revealed that RNDS is expressing potential growth inhibition of B. subtilis and Aspergillus species. It was inactive against R. oligosporus at all concentrations. text/html2010-09-09T21:34:16+01:00http://www.webmedcentral.com/Mr. Ibtissem BouftiraAntioxidative And Free Radical Of Limonium Axillare From Qatarian Coasts
http://www.webmedcentral.com/article_view/570
In the present study, we carried out the antioxidant and antiradical activity of a methanol extract from the leaves of the halophyte plant Limonium axillare (family: Limoniaceae, order: Plumbaginales). Antiradical activity was determined using 1, 1-diphenyl-2-picrylhydrazyl (DPPH) method and antioxidant activity was characterized by NBT/Riboflavin system. The antiradical effect of L. axillare (95 ± 0.5% DPPH scavenging at 1mg/ml) was greater than the synthetic antioxidant BHA. The antioxidant activity (92.96 ± 0.5% of superoxide inhibition) was higher than the standard quercitin. The phytochemical screening of the leaves samples indicates the presence of flavonoids, steroids and alkaloids.text/html2010-09-27T07:11:39+01:00http://www.webmedcentral.com/Prof. Shaibu O BelloComputer Assisted Design and in- Silica Metabolic Exploration of a Hemoglobin Docking Molecule- Early Steps of a Novel Antiplasmodial Agent
http://www.webmedcentral.com/article_view/753
This report presents the early steps in the development of a novel antimalarial agent. Using bio-informatics, human hemoglobin was targeted for docking a ligand at pre-specified regions of its three dimensional structure. Wide ligand search from databases identified atenolol type structures as undesirable ligands that docked close to the heme binding site while Rifampin type structures were identified to dock at the target. Structure analysis was used to develop a library of potential ligand and N-[cyclohexyl (pyrrolidine-2-yl) methyl] naphthalene-2-amine was identified as the lead molecule.
text/html2010-09-30T15:25:20+01:00http://www.webmedcentral.com/Dr. Rakesh PatelDesign Optimization and Evaluation of pH Responsive Prednisolone Sustained Release Tablet for Ileo-colonic Delivery
http://www.webmedcentral.com/article_view/830
The focus of this work is to provide accurate and effective treatment of inflammatory bowel disorders like ulcerative colitis. The necessity and advantages of colon-specific drug delivery systems have been well recognized and documented. Generally, the single approaches to obtain colon-specific delivery achieved limited success. So new combined oral drug delivery system for colon targeting of Prednisolone was developed which contains sustained drug release system of hydroxypropylmethylcellulose, ethyl cellulose, pectin, starch and polymeric coating of Eudragit polymers. DSC, FTIR and accelerated stability studies indicates no possibility of interaction between Prednisolone and other ingredients. The results of the in vitro dissolution tests in 1st fluid (pH 1.2), 2nd fluid (pH 4.5) and 3rd fluid (pH 7.2) indicated absence of drug release in stomach and small intestine and controlled release in colonic medium up to 8 hrs.text/html2010-10-06T19:29:58+01:00http://www.webmedcentral.com/Dr. Ritesh B PatelOptimization Of Propranolol Hydrochloride Controlled Release Matrix Tablet Using Factorial Design
http://www.webmedcentral.com/article_view/914
Purpose: The objective of this study was to prepare Propranolol Hydrochloride controlled release matrix tablets and to investigate the effect of the polymer blends and the polymer concentration on drug release.Method: Propranolol Hydrochloride controlled release matrix tablets were prepared by direct compression technique. Hydroxypropylmethylcellulose K15M (HPMC K15M) and Carbopol 934P were used in formulating the matrix tablets. A 32 full factorial design were applied to carry out systematic studies. The blending ratio of HPMC K15M and Carbopol 934P (X1) and Polymer concentrations (X2) were selected as independent variables. The times required for 50% (t50) and 80% (t80) drug release were selected as dependent variables. The dissolution profile of all the batches was fitted to zero-order, first-order, Higuchi, and Korsemeyer and Peppas models to ascertain the kinetic modeling of drug release.Results: The results clearly indicate that the values of t50, t80, f2 and MDT are strongly dependent on the independent variables. In-vitro drug release profile of all possible batches of factorial design was compared with theoretical drug release profile. The results indicate that batch F7 showed the highest value among all the batches, and it also shows similarity in t50 and t80 values. The f2 value (74) of batch F7 indicates less than 5% difference in in-vitro drug release profile with theoretical release profile.Conclusions: It was observed that the blending ratio of HPMC K15M-Carbopol 934P and polymer concentration have distinct effect on in-vitro drug release profile. Release rate of Propranolol hydrochloride decreased proportionally with increased in concentration of Carbopol 934P and total polymer concentration.
text/html2010-10-07T20:07:14+01:00http://www.webmedcentral.com/Dr. Hitesh R PatelIonotropic Gelation Technique For Microencapsulation Of Antihypertensive Drug
http://www.webmedcentral.com/article_view/922
Micropellets of verapamil hydrochloride were formulated by ionotropic gelation technique using sodium alginate, hydroxy propyl methyl cellulose and hydroxy propyl cellulose. Prepared micropellets were evaluated for flow behaviour, drug entrapment efficiency, in-vitro dissolution and stability studies, including scanning electron microscopy and optical microscopy. Of the nine formulations prepared and evaluated formulations F3, F6 and F9 were found to show satisfactory results. The release of the drug from the micropellets was found to be following Non-Fickian diffusion, Drug diffusion coefficient and correlation coefficient were also assessed using various mathematical models. From the study it was concluded that, prolonged release Verapamil hydrochloride micropellets can be achieved with success using ionotropic gelation technique.text/html2010-10-27T13:05:03+01:00http://www.webmedcentral.com/Dr. Sunil R DhaneshwarDevelopment And Validation Of A Hplc Method For The Determination Of Metformin Hydrochloride, Gliclazide And Piogliglitazone Hydrochloride In Multicomponent Formulation
http://www.webmedcentral.com/article_view/1078
A simple, rapid, and precise reversed-phase high-performance liquid chromatographic method for simultaneous analysis of metformin hydrochloride, gliclazide, and pioglitazone hydrochloride in a tablet dosage form has been developed and validated. Chromatography was performed on a 25 cm × 4.6 mm i.d., 5-μm particle, C18 column with 85:15 (v/v) methanol: 20 mM potassium dihydrogen phosphate buffer as mobile phase at a flow rate of 1.2 ml/min. UV detection at 227 nm; metformin hydrochloride, gliclazide, and pioglitazone hydrochloride were eluted with retention times of 2.15, 3.787, and 4.57 min, respectively. The method was validated in accordance with ICH guidelines. Validation revealed the method is specific, rapid, accurate, precise, reliable, and reproducible. Calibration plots were linear over the concentration ranges 50– 250 μg/ml for metformin hydrochloride, 3.0 –15.0 μg/ml for gliclazide, and 2–10 μg/ml for pioglitazone hydrochloride. Limits of detection were 0.20, 0.04, and 0.10 μg/ml and limits of quantification were 0.75, 0.18, and 0.30 μg/ml for metformin hydrochloride, gliclazide, and pioglitazone hydrochloride, respectively. The high recovery and low coefficients of variation confirm the suitability of the method for simultaneous analysis of the three drugs in tablets. Statistical analysis proves that the method is suitable for the analysis of metformin hydrochloride, gliclazide, and pioglitazone hydrochloride as a bulk drug and in pharmaceutical formulation without any interference from the excipients. It may be extended to study the degradation kinetics of three drugs and also for its estimation in plasma and other biological fluids.text/html2010-11-02T20:40:54+01:00http://www.webmedcentral.com/Ms. Monika BhandariScutellaria Baicalensis Georgi : A Rising Paradigm Of Herbal Remedies
http://www.webmedcentral.com/article_view/1105
There is a growing interest in the use of natural products like herbs, spices and plant extracts in the human food and animal feed industries. Scutellaria baicalensis Georgi from the Labiatae family is one of the fifty fundamental herbs of traditional Chinese medicine is thus used to treat a number of health disorders for over two thousand years. It is also called baical or chinese scutellaria or skullcap. The genus of scutellaria includes approximately 300 species. The NewYork university medical center reports that baicalin can enhance the activity of antibiotics against antibiotic resistant staph bacteria. Other highly preliminary evidence suggests that skullcap have anti diabetic, anti inflammatory, antiviral, antitumor, antioxidative and hepatoprotective properties, anti anxiety, and anti hypertensive effects. The present paper is an overview on scientifically established and published phytopharmacological properties of the plant.text/html2010-11-03T21:20:13+01:00http://www.webmedcentral.com/Mrs. Rajeshree PanigrahiA Review On Fast Dissolving Tablets
http://www.webmedcentral.com/article_view/1107
Recently, fast-dissolving drug delivery systems have started gaining popularity and acceptance as new drug delivery systems, because they are easy to administer and lead to better patient compliance. Usually, elderly people experience difficulty in swallowing the conventional dosage forms (tablets, capsules, solutions and suspensions) because of tremors of extremities and dysphasia. Fast-dissolving drug delivery systems may offer a solution for these problems.text/html2011-01-16T03:38:27+01:00http://www.webmedcentral.com/Mr. Sandeep SinghalHot Melt Extrusion Technique
http://www.webmedcentral.com/article_view/1459
Various approaches have been adopted to address this including preparation of solid dispersions and solid solutions. Hot-melt extrusion is an efficient technology for producing solid molecular dispersions with considerable advantages over solvent-based processes such as spray drying and co-precipitation. Hot-melt extrusion has been demonstrated to provide sustained, modified, and targeted drug delivery. Hot-melt extrusion (HME) is an established process that has been used since the early 1930s, predominately in the plastics manufacturing industry, but also in the food processing industry. Currently, more than half of all plastic products, including bags, sheets, and pipes, are manufactured using HME. Since the advent of plastics production, polymers have been melted and formed to different shapes for a variety of industrial and domestic applications. HME is the process of embedding drug in a polymeric carrier. Specifically, HME dosage forms are complex mixtures of API, functional excipients, and processing aids which are blended using industry-standard equipment. The mixture is processed at elevated temperature and pressure, which disperses the drug in the matrix at a molecular level through the formation of a solid solution. Extruded material can be further processed into a variety of dosage forms, including capsules, tablets and transmucosal systems. Today this technology has found its place in the array of pharmaceutical manufacturing operations. Melt extrusion process are currently applied in the pharmaceutical field for the manufacture of a variety of dosage forms and formulations such as granules, pellets, tablets, suppositories, implants, stents, transdermal systems and ophthalmic inserts. This is relevant for poorly-soluble pharmaceutically active substances, frequently encountered among novel drugs.text/html2011-03-24T20:37:53+01:00http://www.webmedcentral.com/Prof. Nadeem . SiddiquiFluoxetine: Pharmacological and Computational Study
http://www.webmedcentral.com/article_view/1800
Major depressive disorder is currently the fourth leading cause of disease or disability worldwide. Fluoxetine is approved for the treatment of major depression (including paediatric depression), obsessive-compulsive disorder (in both adult and paediatric populations), bulimia nervosa, panic disorder and premenstrual dysphoric disorder. Compared to other popular Selective Serotonin Reuptake Inhibitors (SSRIs), fluoxetine has a strong energizing effect. The study shows fluoxetine is effective in the treatment of depression. The pharmacological and computational studies have been presented.text/html2011-09-09T17:36:13+01:00http://www.webmedcentral.com/Ms. Ramica SharmaEndothelium Dysfunction, Inflammation and Cardiovascular Disorder
http://www.webmedcentral.com/article_view/2176
Vascular endothelium maintains tone and free flow of blood in vessels Several studies indicate that the impairment in the maintenance of vascular tone results in vascular endothelial dysfunction (VED) results from reduced activation of endothelial nitric oxide synthase (eNOS) Various inflammatory mediators are also upregulated during VED Inflammation is a trait of several diseases including rheumatoid arthritis, Alzheimer's disease, asthma and various cardiovascular disorders Interestingly few recent studies demonstrated the role of various inflammatory mediators in the progression of VED and vascular disease associated with this Hence the present review has been designed to delineate the role of various inflammatory mediators in the pathogenesis of inflammation-induced VEDtext/html2011-09-24T14:46:00+01:00http://www.webmedcentral.com/Mr. Rajeev K SinglaAn Overview of Microwave Assisted Technique: Green Synthesis
http://www.webmedcentral.com/article_view/2251
Green chemistry efficiently utilizes (preferably renewable) raw materials, eliminates waste, and avoids the use of toxic or hazardous reagents and solvents in the manufacture and application of chemical products.
Microwave assisted technique opens up new opportunities to the synthetic chemist in the form of new reactions that are not possible using conventional heating and serve a flexible platform for chemical reaction viz. Aldol condensation, Knoevenagel condensation, Beckmann rearrangement, Vilsmeier reaction, Benzil - Benzilic acid rearrangement, Thia – Fries rearrangement, Fischer cyclization, Vilsmeier-Haack reaction, Mannich reaction, Claisen – Schmidt condensation, Gould-Jacob reaction etc.text/html2011-11-07T16:06:07+01:00http://www.webmedcentral.com/Dr. Rajendra K SongaraCounterfeit Medicines: A Regulatory Perspective to Global Threat
http://www.webmedcentral.com/article_view/2431
Counterfeiting is generally perceived by society as a victimless crime, with ‘Fakes’ simply constituting a cheap alternative option, and seen by criminals as having a low risk of prosecution with light penalties relative to the large profits to be made. The reality is that the international trade in counterfeit a product is estimated to exceed six percent of global trade. The range of counterfeit products is extremely broad and the trends indicate that counterfeits no longer confine their activities to luxury goods but increasingly are exploiting consumer goods, including everyday items such as baby food, medicines, cosmetics, aircrafts and vehicle parts.text/html2011-12-18T05:42:16+01:00http://www.webmedcentral.com/Ms. Win Zee TeongInfectious Diarrhoea
http://www.webmedcentral.com/article_view/2686
Diarrhoea is the passage of three or more loose or liquid stools per day, or more frequently than it is normal for the individual. It is usually a symptom of gastrointestinal tract infection caused by bacteria. Some common causing bacteria are Campylobacter, Salmonella, Shigella and Escherichia coli. These microorganisms are spread through contaminated water or food, unsanitary disposal of human waste and poor personal hygiene. Antibiotics used in the treatment of gastrointestinal tract infection are ampicillin, ceftrixone, ciprofloxacin, cotrimoxazole, a combination of trimethoprim and sulfamethoxazole; and macrolides, including erythromycin and azithromycin. The alternative treatments are fluid replacement, advice about eating and anti-diarrhoea medicines include loperamide, codeine and activated charcoal. Gastrointestinal tract infection can be prevented by improving water supplies and sanitation, hand washing with soap and consuming clean food.text/html2011-12-18T05:41:45+01:00http://www.webmedcentral.com/Mr. Chai C HeanFungal Disease and Therapy
http://www.webmedcentral.com/article_view/2693
There are many types of fungal disease include superficial mycoses, cutaneous mycoses, subcutaneous mycoses, systemic mycoses, opportunistic mycoses and non-opportunistic mycoses. Onychomycosis is one type of superficial mycoses which normally occurs in finger and toe nails. It is diagnosed by using direct microscopy and culture to identify whether the causing agents are dermatophytes, yeast or molds. Terbinafine is the normal drug used to treat onychomycosis given by oral or cream form. Histoplasmosis is a systemic infection which infects the lungs first then spread to other parts the body. For its diagnosis, several methods chest X-ray, computerized tomography (CT) scan, fungal culture and blood test are used to identify the causing agent which is H.capsulatum. Aspergillosis is a type of opportunistic fungal infection which spread throughout the body usually caused by Aspergillus fumigatus and Aspergillus niger. It is difficult to diagnose aspergillosis as it normally infects immunocompromised patients and biopsies are one of the ways to diagnose aspergillosis in healthy patient. Itraconazole is the common drug to cure aspergillosis and histoplasmosis.text/html2011-12-19T15:31:23+01:00http://www.webmedcentral.com/Mr. Kwek C HauAn Illustrated Review About Aminoglycosides
http://www.webmedcentral.com/article_view/2744
Aminoglycoside is a potent antibiotic that stops the protein synthesis continuation by binding to the ribosomal decoding site. They are used to treat infection caused by the aerobic, gram-negative and certain gram-positive organisms. The most commonly used aminoglycoside is Gentamicin. Generally, single daily dosing of aminoglycosides is appeared to be safer, cost effective and efficacious. Prolonged use of the drugs will lead to side effects such as ototoxicity and nephrotoxicity. Resistance towards aminoglycoside is possible but it rarely happens. The structures activity relationship (SAR) of some aminoglycoside antibiotics is further reviewed in this paper.
text/html2011-12-19T15:30:30+01:00http://www.webmedcentral.com/Ms. Lim Soo HuiAntituberculosis
http://www.webmedcentral.com/article_view/2751
Tuberculosis(TB) is an airborne infection caused by Myobacterium tuberculosis which can be fatal. The first antituberculosis agent discovered is streptomycin. Combination of drug therapy is used to prevent resistance. BCG vaccine prevents TB in children. Symptoms of TB are coughing, fever, weight loss, night sweats and chest pain. High risk population includes elderly, baby and patient with weak immune system. Two types of TB are childhood-type tuberculosis and adult-type tuberculosis. There are 4 types of first-line antituberculosis drugs: isoniazid, rifampin, pyrazinamide and ethambutol. Isoniazid is used in latent tuberculosis and preventive treatment. It inhibits biosynthesis of mycolic acid. It is absorbed in gastrointestinal tract, distributed into all body fluids include CNS, metabolised in liver, and excreted in kidney. Side effects of isoniazid include peripheral neuritis and hepatotoxicity. Rifampin belongs to rifamycin group which inhibits bacterial enzyme for DNA transcription. It is absorbed orally, distributed into many organs and body fluids, metabolised in liver, and excreted through bile. Side effect of rifampin is gastrointestinal disturbance. Pyrazinamide is usually used in combination with isoniazid and rifampicin. It inhibits fatty acid synthetase in bacteria. It is absorbed in gastrointestinal tract, distributed into most fluid and tissues, and excreted by kidney. Side effects of pyrazinamide include stomach upset and jaundice. Ethambutol is a bacteriostatic agent which inhibits synthesis of metabolites important in cell metabolism. It is absorbed orally, distributed widely, metabolised in liver and excreted in kidney. Side effects of ethambutol include hyperuricemia and optic neuritis. Preventive measures for tuberculosis include awareness campaign, administration of antibiotic and isolation of TB patient. In conclusion, TB is fatal and contagious disease. However, 90% of the TB patient are completely cured and recover after received whole course of treatment. Multiple-Drug Resistance TB may emerge as a result of irregular treatment.text/html2011-12-20T17:39:10+01:00http://www.webmedcentral.com/Mr. John Yip K YongTransparent Plastic Envelope for Dispensing Antibiotics - The Best Option in the Market?
http://www.webmedcentral.com/article_view/2755
Different antibiotics have different characteristics but the aspect of antibiotic stability is the main concern of the pharmacist when dispensing the drug. The stability of drug such as chemical stability, physical stability, microbiological stability, therapeutic stability and toxicological stability will ensure its therapeutic effect. There are some factors that may affect antibiotics’ effectiveness like, hydrolysis, oxidation, epimerization, photolysis, temperature and microbial contamination. These factors are avoidable by dispensing antibiotics with a proper container. Transparent plastic envelope is the major method in dispensing drugs, but it was not fully secure the stability of drug. Some other alternatives such as, blister packaging, strip packaging and plastic bottle are more preferred compared to transparent plastic envelope.text/html2011-12-22T17:52:11+01:00http://www.webmedcentral.com/Mr. Mohamad Taufik B YusofAn Illustrated Review on Penicillin And Cephalosporin : An Instant Study Guide For Pharmacy Students
http://www.webmedcentral.com/article_view/2776
Study material can be presented in an instant study guide to help pharmacy students read through and understand quickly rather than digesting facts in long essay form. The review is done for instant use by pharmacy students for an overall revision or rapid review on the topic of Penicillin and Cephalosporin. The approaches used in this instant study guide are illustrations like diagrams, pictures, flowchart, tables, structures and coloured texts. Flow chart simplifies the complex explanation of words. Colors stimulate our visual senses and help in memorizing as it improves attention. The table helps the students to see the whole picture of the facts clearly and guide them on the important points that they have to know. We also apply the concept of ‘a picture worth a thousand words’. Pictures can stimulate brain to analyze faster rather than seeing thousands of words. Each part of the structures is fitted with important points so that students can read and straight away gain understanding. The study guide helps the pharmacy students to gain essential information and understand the concept better and faster.text/html2011-12-26T09:56:49+01:00http://www.webmedcentral.com/Mr. Rajeev K SinglaAn Overveiw On Fast Dissolving Tablet
http://www.webmedcentral.com/article_view/2786
Oral route having the highest patient compliance is regarded as the most convenient, safest and also the most economical method of drug delivery. Fast dissolving tablets is one such most advantageous example of the oral drug delivery. These tablets readily dissolve or disintegrate in the saliva i.e. within less than 60sec without the need for water. They have been formulated for pediatric, geriatric and bedridden patients. These type of dosage forms are also ideal for active patients who are busy and traveling and may not have access to water. FDTs have gained considerable attention for those patients who have difficulties in swallowing because of dysphagia, hand tremors problems and have additional advantage for unconscious, young patients with underdeveloped muscular and nervous system. This review describes the various advantages, limitations, desired characteristics, formulation aspects, super-disintegrants employed, technologies developed for FDTs, evaluation tests, and marketed formulations.text/html2012-01-17T21:35:10+01:00http://www.webmedcentral.com/Mr. Rajeev K SinglaImpurities in Pharmaceutical Dosage Form: A Subject Matter of Great Concern
http://www.webmedcentral.com/article_view/2884
According to FDA any substance that is represented for use in a drug and that, when used in the manufacturing, processing, or packaging of a drug, becomes an active ingredient or a finished dosage form of the drug.Impurities in pharmaceuticals are the unwanted chemicals that remain with the active pharmaceutical ingredients (APIs), or develop during formulation, or upon aging of both API and formulated APIs to medicines. The presence of these unwanted chemicals even in small amounts may influence the efficacy and safety of the pharmaceutical products. Impurity profiling (i.e., the identity as well as the quantity of impurity in the pharmaceuticals), is now getting receiving important critical attention from regulatory authorities. The different pharmacopoeias, such as the British Pharmacopoeia (BP) and the United States Pharmacopoeia (USP), are slowly incorporating limits to allowable levels of impurities present in the APIs or formulations.There is an ever increasing interest in impurities present in API’s. Recently, not only purity profile but also impurity profile has become essential as per various regulatory requirements. In the pharmaceutical world, an impurity is considered as any other organic material, besides the drug substance, or ingredients, arise out of synthesis or unwanted chemicals that remains with API’s. Impurity control in pharmaceutical products is a primary goal of drug development [1].According to ICH, an impurity in a drug substance is defined as-“any component of the new drug substance that is not the chemical entity defined as the new drug substance”. There is an ever increasing interest in impurities present in APIs recently, not only purity profile but also impurity profile has become essential as per various regulatory requirements. The presence of the unwanted chemicals, even in small amount, may influence the efficacy and safety of the pharmaceutical products.“In the pharmaceutical world, an impurity is considered as any other organic material, besides the drug substance, or ingredients, arise out of synthesis or unwanted chemicals that remains with API’s”The impurity may be developed either during formulation, or upon aging of both API’s and formulated API’s in medicines and can be explained using Multidisciplinary approach.The International Conference on Harmonization of Technical Requirements for Registration of Pharmaceuticals for Human Use (ICH) has also published guidelines for validation of methods for analyzing impurities in new drug substances, products, residual solvents and microbiological impurities.text/html2012-02-29T14:49:25+01:00http://www.webmedcentral.com/Mrs. Rajeshree PanigrahiFormulation and Evaluation of Fast Dissolving Tablet of Gliclazide using Combination of Superdisintegrants
http://www.webmedcentral.com/article_view/3121
Objective of this study was to formulate directly compressible fast dissolving tablets of Gliclazide with sufficient mechanical integrity, content uniformity, and acceptable palatability to assist patients of any age group for easy administration. Effect of varying concentrations of different combination of superdisintegrants such as crospovidone, crosscarmellose sodium, and sodium starch glycolate on disintegration time was studied. Tablets were evaluated for weight variation, thickness, hardness, friability, taste, drug content, in vitro disintegrating time and in vitro drug release. Other parameters such as wetting time, water absorption ratio were also evaluated. The disintegration time of the optimized C4 batch was found to be 10.8 secs.text/html2012-02-29T14:47:33+01:00http://www.webmedcentral.com/Mr. Prasanta K ChoudhuryNovel Approaches and Developments in Colon Specific Drug Delivery Systems- A Review
http://www.webmedcentral.com/article_view/3114
Colon specific drug delivery has gained increased importance not for the treatment of local diseases associated with the colon but also as potential site for systemic delivery of therapeutic proteins and peptides. Colon is a site where both local and systemic delivery of drug can take place. Treatment could be more effective if it is possible for drug to be directly to colon. Systemic side effects can also be reduced the primary approaches to obtain colon specific delivery is based on prodrugs, pH and time dependent systems (or) microflora activated systems and have achieved limited success only. Most recently new colon – specific delivery systems are developed. These are pressure controlled colon delivery capsules, CODESTM, colon drug delivery systems based on pectin and galactomam coating, hydrogels, osmotic controlled drug delivery system, pulsincap system, time clock system, chronotropic system, enterion capsule technology. The review is aimed at understanding above pharmaceutical approaches to colon targeted drug delivery systems for better therapeutic action without compromising on drug degradation (or) its low bioavailability. Key words: Colon Specific Drug Delivery System, Advantages, Approaches.text/html2012-04-16T12:43:15+01:00http://www.webmedcentral.com/Mrs. Rajeshree PanigrahiEffect of Combination of Superdisintegrants on Fast Dissolving Tablet of Gliclazide
http://www.webmedcentral.com/article_view/3257
Objective of this study was to formulate directly compressible fast dissolving tablets of Gliclazide with sufficient mechanical integrity, content uniformity, and acceptable palatability to assist patients of any age group for easy administration and to show the effect of maximum concentration (10 %) of different combination of superdisintegrants such as crospovidone, croscarmellose sodium, and sodium starch glycolate on disintegration time. Tablets were evaluated for weight variation, thickness, hardness, friability, taste, drug content, in vitro disintegrating time and in vitro drug release. Other parameters such as wetting time, water absorption ratio were also evaluated. The disintegration time of the optimized C5 batch was found to be 24.7 secs.text/html2012-05-02T19:57:05+01:00http://www.webmedcentral.com/Mr. Prasanta K ChoudhuryInvestigation of Drug Polymer Compatibility: Formulation and Characterization of Metronidazole Microspheres for Colonic Delivery.
http://www.webmedcentral.com/article_view/3253
For the design and development of any novel formulation, assessment of compatibility of drug with excipients by different techniques such as thermal and isothermal stress testing are recommended. During pre-formulation studies common methods like UV-Spectrophotometric methods, FTIR are used for the study of compatibility. In the present investigation drug-excepient compatibility study of was conducted for metronidazole with ethyl cellulose to formulate microspheres by using different ratio of drug: polymer for colonic delivery. The drug and polymer mixtures were stored at 50 °C for 2 weeks. The samples were then characterized using UV Spectrophotometric method, FTIR. The results show that metronidazole was compatible with ethyl cellulose; hence ethyl cellulose can be used for formulation of metronidazole microspheres. Microspheres were prepared by modified Novel Quasiemulsification solvent-diffusion method to study the effect of ethyl cellulose on drug release with different proportions of metronidazole and ethyl cellulose. Prepared microspheres of ethyl cellulose were evaluated for size, morphology, sphericity study, percentage yield, loose surface crystal study, drug content and entrapment efficiency. In vitro drug release study was conducted by buffer change method to mimic Gastro Intestinal environment. The investigations revealed that microspheres prepared with metronidazole: ethyl cellulose ratio (1:2) show only 19.394 ±0.67% drug release in first 5 hours and 46.72 ±0.69% in 12 hours, which prove the potentiality of ethyl cellulose for colonic delivery of drugs.
Keywords: Metronidazole, Compatibility, Polymers, UV Spectrophotometric methods, FTIR, Colonic drug delivery, Quasiemulsification Solvent-diffusion techniquetext/html2012-05-26T11:28:14+01:00http://www.webmedcentral.com/Mr. Rajeev K SinglaReview on the Pharmacological Properties of Cocos Nucifera Endocarp
http://www.webmedcentral.com/article_view/3413
Fruits of cocos nucifera have long been used in the traditional medicine for the treatment of metabolic disorders. Endocarp of cocos nucifera was supposed to be the hardest part of the its fruit, but ironically richest source of phenolic and flavanoid content.Scientific data has been found as evident for antioxidant, antimicrobial, vasorelaxant,antihypertensive and inhibitory effect on oral microflora of cocos nucifera endocarp. Current review article covers the relevancy of cocos nucifera endocarp in the medicinal world.text/html2012-07-31T18:26:15+01:00http://www.webmedcentral.com/Mr. Rajeev K SinglaTraditional Systems of Medicine- Now & Forever
http://www.webmedcentral.com/article_view/3551
India has a rich heritage of traditional medicine and the traditional health care system have been flourishing for many centuries. traditional medicine, defined by the WHO as "medical knowledge systems that developed over generations within various societies before the era of modern medicine, including the health practices, approaches, knowledge and beliefs incorporating plant, animal and mineral-based medicines, spiritual therapies, manual techniques and exercises, applied singularly or in combination to treat, diagnose and prevent illnesses or maintain well-being" is used globally and has rapidly growing economic importance. In developing countries, traditional medicine is often the only accessible and affordable treatment available. In Latin America, the WHO regional office for the Americas (AMRO/PAHO) reports that 71% of the population in Chile and 40% of the population in Colombia has used traditional medicine. In many Asian countries traditional medicine is widely used, even though western medicine is often readily available. In Japan, 60-70% of allopathic doctors prescribe traditional medicines for their patients. In the US the number of visits to providers of complementary alternative medicine (CAM, codified herbal medicine) now exceeds by far the number of visits to all primary care physicians.[1,2]text/html2012-08-03T19:11:03+01:00http://www.webmedcentral.com/Mr. Prasanta K ChoudhuryComparative Studies on Effects of Different Colonic Polymers for Design and Development of Diclofenac Sodium Sustained Release Tablets
http://www.webmedcentral.com/article_view/3618
In the present investigation, an attempt has been made to reduce frequency of administration and increase therapeutic efficacy, there by improve patient compliance, by developing sustained release tablets of diclofenac sodium (DS). Sustained release tablets of DS, were developed by wet granulation method using different colonic polymers, (Guar gum, Ethyl cellulose, Acrycoat L100) with Drug: polymer ratios 1:2, which delivers the drug specifically into colonic region. Formulations were also prepared with combination polymers keeping drug: polymer ratio constant i.e. 1:2, where two polymers were used of equal proportion instead of the single polymer. All the lubricated formulations were compressed using 8 mm flat faced punches. Compressed tablets were evaluated for weight uniformity, drug content, friability, hardness, thickness, In vitro drug release study was conducted by buffer change method to mimic GIT environment. Among different formulations, F3 showed sustained release of drug for 10 hours with 67.23% release. The effect of other parameters like compression coating with Acrycoat L100, pH of dissolution medium was also studied. Pharmaco-equivalence of the prepared formulation with a standard marketed formulation was also carried out. The kinetic treatment showed that the release of drug follows zero order kinetic (R2 = 0.9758). Korsmeyer and Peppas equation gave value of n = 0.9409 which was close to one, indicating that the drug was released by zero order kinetic. Thus, Guar gum, Ethyl cellulose and Acrycoat L100 can be used as an effective matrix former, to extend the release of diclofenac sodium.
Keywords: Diclofenac Sodium, Colonic polymers, Sustained release, Pharmaco-equivalence, drug release kineticstext/html2012-08-27T16:36:58+01:00http://www.webmedcentral.com/Mr. Rajeev K SinglaParkinson\'s Disease: Diagnosis, Therapeutics & Management
http://www.webmedcentral.com/article_view/3670
Parkinson disease is a chronic, progressive neurodegenerative movement which affects about 1% of population over the age of 60.In Parkinson disease there is loss of dopaminergic neurons in substantia nigra[1],[2] which affects nerve cells (neurons) in an area of the brain near the neck. These nerve cells normally produce dopamine, a chemical that transmits signals between areas in the brain. These signals coordinate smooth, balanced muscle movement. Parkinson’s disease causes the neurons to die, leading to a lack of dopamine in the brain. With the loss of dopamine, patients lose the ability to control their body movements.[3]
People with PD classically present with the symptoms and signs associated with parkinsonism, namely hypokinesia (ie poverty of movement), bradykinesia (ie slowness of movement), rigidity and rest tremor.Parkinsonism can also be caused by drugs and less common conditions such as: multiple cerebral infarction, and degenerative conditions such as progressive supranuclear palsy (PSP) and multiple system atrophy (MSA).Although PD is predominantly a movement disorder, other impairments frequently develop, including psychiatric problems such as depression and dementia. Autonomic disturbances and pain may later ensue, and the condition progresses to cause significant disability and handicap with impaired quality of life for the affected person. Family and carers may also be affected indirectly.[2]
Parkinson affects various functional activities such as balance, walking, speech, handwriting, typing, fastening buttons, driving, and many other simple, or complex but familiar and routine activities[4] Early in the course of the disease, the most obvious symptoms are movement-related, including shaking,rigidity, slowness of movement and difficulty with walking and gait. Later, cognitive and behavioural problems may arise, with dementia commonly occurring in the advanced stages of the disease. Other symptoms include sensory, sleep and emotional problems. PD is more common in the elderly with most cases occurring after the age of 50. The main motor symptoms are collectively called parkinsonism, or a "parkinsonian syndrome".
Parkinson's disease is often defined as a Parkinsonian syndrome that is idiopathic (having no known cause), although some atypical cases have a genetic origin. Many risk and protective factors have been investigated.The clearest evidence is for an increased risk of PD in people exposed to certain pesticides and a reduced risk in tobacco smokers. The pathology of the disease is characterized by the accumulation of a protein called alpha-synuclein into inclusions called Lewy bodies in neurons, and from insufficient formation and activity of dopamine produced in certain neurons of parts of the midbrain. Diagnosis of typical cases is mainly based on symptoms, with tests such as neuroimaging being used for confirmation. Modern treatments are effective at managing the early motor symptoms of the disease, mainly through the use of levodopa and dopamine agonists. As the disease progresses and dopamine neurons continue to be lost, a point eventually arrives at which these drugs become ineffective at treating the symptoms and at the same time produce a complication called dyskinesia, marked by involuntary writhing movements. Diet and some forms of rehabilitation have shown some effectiveness at alleviating symptoms. Surgery and deep brain stimulation have been used to reduce motor symptoms as a last resort in severe cases where drugs are ineffective. Research directions include a search of new animal models of the disease and investigations of the potential usefulness of gene therapy, stem cell transplants and neuroprotective agents.The disease is named after the English doctor James Parkinson, who published the first detailed description in An Essay on the Shaking Palsy in 1817. The main motor symptoms are collectively called parkinsonism, or a "parkinsonian syndrome". Parkinson's disease is often defined as a parkinsonian syndrome that is idiopathic (having no known cause), although some atypical cases have a genetic origin. Many risk and protective factors have been investigated: the clearest evidence is for an increased risk of PD in people exposed to certain pesticides and a reduced risk in tobacco smokers. The pathology of the disease is characterized by the accumulation of a protein called alpha-synuclein into inclusions called Lewy bodies in neurons, and from insufficient formation and activity of dopamine produced in certain neurons within parts of the midbrain. Lewy bodies are the pathological hallmark of the idiopathic disorder, and the distribution of the Lewy bodies throughout the Parkinsonian brain varies from one individual to another. The anatomical distribution of the Lewy bodies is often directly related to the expression and degree of the clinical symptoms of each individual. Diagnosis of typical cases is mainly based on symptoms, with tests such as neuroimaging being used for confirmation. Modern treatments are effective at managing the early motor symptoms of the disease, mainly through the use of levodopa and dopamine agonists. As the disease progresses and dopaminergic neurons continue to be lost, a point eventually arrives at which these drugs become ineffective at treating the symptoms and at the same time produce a complication called dyskinesia, marked by involuntary writhing movements. Diet and some forms of rehabilitation have shown some effectiveness at alleviating symptoms. Surgery and deep brain stimulation have been used to reduce motor symptoms as a last resort in severe cases where drugs are ineffective. Research directions include investigations into new animal models of the disease and of the potential usefulness of gene therapy, stem cell transplants and neuroprotective agents. Medications to treat non-movement-related symptoms of PD, such as sleep disturbances and emotional problems, also exist.Several major organizations promote research and improvement of quality of life of those with the disease and their families. Public awareness campaigns include Parkinson's disease day (on the birthday of James Parkinson, April 11) and the use of a red tulip as the symbol of the disease.[5]
A region-specific selective loss of dopaminergic (DAergic) neuromelanin-containing neurons from the pars compacta of the substantia nigra (SNpc) is the pathological hallmark of PD. However, cell loss in the locuscoeruleus, dorsal nuclei of the vagus, raphe nuclei, nucleusbasalis of Meynert, and some other catecholaminergic brain stem structures including the ventrotegmental area also exists[6]. This neuronal cell loss is accompanied by intraneuronal inclusions: the Lewy body (LB). α-synuclein represents one of the most abundant proteins found in LBs, and it may play a pivotal role in the progression of PD. Since the degree of DAergic neuronal loss correlates with the severity of PD, levodopa (L-dopa), a chemical precursor of dopamine (DA) is the most effective drug for the symptomatic treatment of PD. Unfortunately, the clinical efficacy often declines after long-term levodopa replacement therapy (DA replacement therapy; DRT), and additionally, disabling adverse effects appear, most notably motor fluctuation such as the wearing-off or on-off phenomenon and dyskinesia. DA receptor agonists are even regarded as first choice in de novo and young PD patients to delay onset of levodopa therapy. They are also used as combination therapy together with levodopa to retard the development of motor complications in advanced stages of PD. DA receptor agonists appear to act by not only direct stimulation of postsynaptic DA receptors but also presynaptic receptors. However, DA receptor agonists may be slightly less potent medicines than levodopa and may be poorly tolerated by older PD patients. Additionally, long-term therapy with traditional ergot DA receptor agonists may result in valvular heart disease . A lack of spontaneity or reduced motivation (i.e., anhedonia) is the most troublesome issue in the therapy of advanced stage of PD patients. Medicines with high affinity for the DA receptors potentially improve these symptoms , however, hedonistic dysregulation syndrome or DA dysregulation syndrome (DDS) has emerged as a serious issue in PD with long-term DRT [7].
1.1 PHYSIOLOGICAL CHARACTERIZATION OF DOPAMINE RECEPTOR
DA is a prototypical slow neurotransmitter that plays significant roles in a variety of not only motor functions but also cognitive, motivational, and neuroendocrine . All members of receptors share a number of structural characteristics such as
(1) seven hydrophobic transmembrane stretches
(2) significant amount of amino acid sequence identity between different subfamily within these transmembrane regions and posttranslational modifications such as glycosylation and phosphorylation.
(3) conserved amino acid residues that are involved in interaction of G-protein and in binding agonists.
On the basis of biochemical, pharmacological, and physiological criteria, DA receptors have been classified into two subfamilies, termed D1 and D2 . Genes encoding members of the DA receptor family are part of a larger superfamily of genes comprising the G protein-coupled superfamily receptors (GPCRs) . G protein-related actions of GPCRs are mediated by a subset of the heteromeric G protein subtypes. In general, G proteins consist of three protein subunits α, β, and γ. The α-subunits are functionally classified into several classes such as Gαs, Gαi, Gαo, Gαolf, Gαt, Gαq, and Gα12 and determine actions of GPCRs. Upon ligand binding, Gα proteins release GDP and newly bind GTP, then βγ-complex dissociates from α-subunit. Both the α-subunit and the βγ-complex can transduce the signal to activate a number of effector systems. For example, the activation of Gαs subunit stimulates adenylate cyclase (AC), whereas the activation of Gαi subunit inhibits AC.
The D1 subfamily, including D1 and D5, are generally coupled to Gαs, and Gαolf and stimulate the production of cAMP and activate protein kinase A (PKA) (Table). The D2 subfamily, including D2, D3, and D4, are coupled to Gαi and Gαo and downregulate the production of cAMP via inhibiting AC, resulting in a decrease in PKA activity (Table). One of a PKA substrate, DA and cAMP-regulated phosphoprotein 32-kDa (DARPP-32) is known to be involved in DA receptor signaling. DARPP-32 is a multifunctional phosphoprotein and acts as an integrator involved in the modulation of cell signaling in response to multiple neurotransmitters, including DA . Activated DARPP-32 inhibits protein phosphatase 1 (PP1) and results in activation of mitogen-activated protein (MAP) kinases, such as extracellular signal-regulated kinase (ERK) and MAP/ERK kinase (MEK). MAP kinases play a pivotal role in the regulation of synaptic plasticity and have been shown to be signaling intermediates that are involved in the regulation of DA-associated behavior .
see illustration 1
The D1 receptor subfamily is expressed in multiple brain regions, including the cortex, hippocampus, amygdala, and most intensively, the striatum, olfactory bulb, and substantia nigra . In the cortex and hippocampus, D1 receptors are expressed in a subpopulation of interneurons , but are primarily expressed in pyramidal neurons, with a predominant subcellular localization in the spines of apical dendrites . D5 receptors coexpresses with D1 receptors in cortical pyramidal neurons, and are predominately localized in shafts (Table).
The expression and localization of D2 receptor subfamily have also been investigated at the cellularand subcellular levels . There are two major D2 receptor variants that have been termed D2-long (D2L) and D2-short (D2S) . D2L contains an additional 29 amino acids in the third cytoplasmic loop. D2L and D2S expressed mainly postsynaptically and presynaptically, respectively. D2S might function as autoreceptor that decreases DA release, resulting in decreased locomotor activity; however, activation of postsynaptic D2 receptors stimulates locomotion. D2 receptors, the predominant subtype of thisclass, are expressed in the pituitary gland and basal ganglia (striatum and substantia nigra) and localized in both pre- and postsynaptic structures. Presynaptically, D2 receptors areassociated with both forebrain projecting DAergic afferents and glutamatergic terminalsin the striatum and prefrontal cortex (PFC). Postsynaptically, D2 receptors are concentrated inshafts and spines of both cortical pyramidal neurons and striatopallidal neurons. While both D1 and D2 receptors are abundant in the striatum, the expression pattern of D1 and D2 receptors in the axon terminals, dendrites, and spines are obviously different by electron microscopic analysis . These findings indicate segregated circuit via D1 and D2 receptors in the striatum. D3 receptors are expressed in the olfactory tubercle, nucleus accumbens, striatum, and substantia nigra. Importantly, D3 receptors are also found in limbic system such as hippocampus, septum, or mammillary nuclei of the hypothalamus. The D4 receptors, known to have an unusually high affinity for the atypicalneuroleptic clozapine, are localized in thefrontal cortex, medulla, amygdala, hypothalamus, mesencephalon, and nucleusaccumbens. It has been shown that lower level of D4 receptor expression is detected in the basal ganglia. In the rat central nervous system, the relative abundance of the DA receptors is D1 > D2 > D3 > D5 > D4[8]
It has long been suggested that DA dysfunction plays a major role in the pathogenesis of schizophrenia. Antipsychotics such as chlorpromazine and haloperidol act primarily as D2 receptor antagonists (Table a). These D2 receptor blockades are effective in attenuating positive symptoms of schizophrenia (e.g., hallucinations and delusions) associated with acute episodes as well as preventing psychotic relapse. Wong et al. demonstrated that D2 receptor density in the caudate nucleus is elevated in drug-naïve schizophrenia patients with positron emission tomography (PET) study . Breier et al. also showed that patients with schizophrenia compared with healthy volunteers had significantly greater amphetamine-related reductions in radioligand [11C] raclopride-specific binding ratio with PET . This result indicates that schizophrenia is associated with elevated amphetamine-induced synaptic DA concentrations (Table a). Studies also showed that increased striatal DA synthesis capacity in unmedicated schizophrenia patients . These results indicated that the pool of releasable DA is increased in patients with schizophrenic psychosis. Kramer et al. demonstrated that a selective D4 receptor agonist L-745870 is ineffective in patients with schizophrenia .
1.2 GENETIC MANUPULATION OF DOPAMINE RECEPTOR
The facts regarding the contribution of D1- and D2-type DA receptors in the genesis of the behavioral and neurochemical Parkinsonian phenotype have been provided byclassic pharmacological approaches. Recently, genetically modified mice of DA receptors are also clarifying the significance of specific effects of DA-related neuronal physiology and pathophysiology.
In 1994, Xu et al. and Drago et al. generated D1 receptor-deficient mice . Xu et al. demonstrated that these mice also appear to exhibit a general behavioral hyperactivity during both phases of light-dark cycle ; however, Drago et al. described that the locomotor activity of knockout mice did not differ significantly from that of normal control except for displaying a significant decrease in rearing behavior . Test for akinesia were normal. Moreover, Gantois et al. used a Cre/Lox transgenic approach to generate ananimal model in which D1 receptor-expressing cells are progressively ablated in the postnatal brain . Whereas no differences in locomotor activity were found between the mutated mice and control, mutant showed hyperactivity in a novel environment. Abnormal oral behaviors such as chewing and sifting, limb-clasping dystonic posture, and spontaneous seizure are also found in mutant mice. Increased locomotor activity of D1 receptor-deficient mice is cancelled with a D1/D5 receptor antagonist SCH 23390, indicating that D1 and D5 receptors can exert distinct and complex physiological actions in locomotor activity .
In contrast to disruption of D1 receptor subfamily, spontaneous PD-like locomotor impairment is found in D2 receptor subfamily knockout mice. D2 receptor-deficient mice exhibit significantly reduced spontaneous movements in behavioral tests . However, Kelly et al. demonstrated that striatal tissue content of monoamines and their metabolites from C57BL/6 congenic strain of D2 receptor mutant mice did not differ from those of wild type, and they found no evidence for supersensitive D1, D3, or D4 DA receptors in the D2 receptor knockout mice . Recently, Tinsley et al. showed that LB-like cytoplasmic inclusions containing α-synuclein and ubiquitin were present in substantia nigra neurons of older D2 receptor knockout mice (>18 months old) . Diffuse cytosolic α-synuclein immunoreactivity in nigral neurons increased with age in both wild-type and knockout mice, most likely because of redistribution of α-synuclein from striatal terminals to substantia nigra cell bodies. Gene and protein expression studies showed endoplasmic reticulum (ER) stress and changes in trafficking and autophagic pathways, indicating that these changes were accompanied by a loss of DA terminals in the dorsal striatum . Wang et al. showed behavioral alteration in the D2L receptor-deficient mice . The knockout mice display reduced locomotor activity and rearing behavior and reduced sensitivity to haloperidol-induced catalepsy. These results indicate that D2L might have a bigger impact on certain types of motor functions, and blockade of D2L might contribute more than blockade of D2S to the extrapyramidal side effects (or parkinsonism) that are commonly associated with typical antipsychotic drugs . In addition, D2 receptor plays a pivotal role in the striatal processing of motor information received from the cortex in the generation of striatal synaptic plasticity. Whereas tetanic stimulation of corticostriatal fibers produced long-term potentiation (LTP) in the D2 receptor-null mice, long-term depression (LTD) is usually recorded in wild-type mice . The LTP in knockout mice is blocked by an NMDA receptor antagonist, indicating that D2 receptor is involved in the formation of striatal LTD and exerts a negative control in the expression of an NMDA-mediated long-term LTP at corticostriatal synapses. Adenosine A2A receptors (A2AR) are known to coexpress D2 receptors in striatopallidal neurons, and A2AR-D2 receptor interaction modulates DA-mediated signaling . A2AR selective antagonist, (E)-1,3-diethyl-8-(3,4-dimethoxystyryl)-7-methyl-3,7-dihydro-1Hpurine-2,6-dione (KW-6002, Istradefylline), exhibits anti-Parkinsonian activities . Aoyama et al. demonstrated that locomotor impairment can be relieved by KW-6002 treatment in D2 receptor knockout mice . Furthermore, the level of the expression of enkephalin and substance P is elevated to normal levels after A2AR antagonist treatment. These results show that A2AR and D2 receptor have antagonistic and independent activities in controlling neuronal and motor functions in the basal ganglia.
Although D3 receptor-deficient mice do not exhibit parkinsonism, it is quite important to elucidate specific behavioral alteration in the knockout mice for understanding clinical features of pharmacotherapeutic DA receptor agonists in the treatment of PD. D3 mutant mice exhibit hyperactivity in novel and exploratory environment and rearing behavior . These mutant mice demonstrated that both D1- and D2-receptor-binding sites are present in the dorsal and ventral striatum and the distributions and the densities of both binding sites in the mutants and controls are qualitatively and quantitatively similar . Importantly, hyperactivity of mutant mice is caused by response to combinations of D1 and D2 receptor subfamily agonists, cocaine, and amphetamine. Carta et al. also showed that acute administration of cocaine resulted in increasing mRNA level of c-fos and dynorphin in the dorsal and ventral striatum of D3 receptor knockout mice, indicating D3 receptor plays a role on gene regulation in the DA system . Moreover, Schmauss found that c-fos mRNA levels expressed in response to D1 agonist or methamphetamine administration is significantly blunted in D3 receptor-deficient (and also D2 receptor-deficient) mice . D3 receptor mutants exhibit deficits in their spatial working memory, and methamphetamine pretreatment does not rescue this memory deficit of D3 mutants . These results indicate that the constitutive inactivation of D3 receptors leads to a decrease in agonist-promoted D1 receptor activity. D’Agata et al. have investigated parkin expression profile in D3 knockout mice . parkin is known as one of the causative genes of autosomal recessive juvenile Parkinson’s disease. Parkin protein has an E3 ubiquitin-ligase activity, and loss of parkin function may result in accumulation of unnecessary molecules that lead to the degeneration of neurons. Real-time PCR analysis showed a different quantitative expression of parkin gene in mutant compared to control mice. Furthermore, immunoreactivity of parkin showed a higher intensity in D3 receptor knockout mice compared to wild type by Western blot analysis using parkin mouse monoclonal antibody . Karasinska et al. generated mice lacking both D1 and D3 receptors and investigated psychostimulant-induced behavior . Administration of cocaine increased locomotor activity in wild-type and D3 knockout mice, failed to stimulate activityin D1 knockout mice, and reduced activity in D1/D3 knockout mice. Karasinska et al. discussed the significance of expression level of phosphorylated cAMP-responsive element-binding protein (pCREB) in the striatum. CREB is activated by phosphorylation in striatal regions following DA receptor activation. Striatal pCREB levels following acute cocaine were increased in D3 mutant mice and decreased in D1 and D1/D3 mutant mice . The change of locomotor activity of D3 mutant mice is controversial. Jung et al. demonstrated that the activity of D2/D3 double mutants is significantly reduced not only when compared to wild type but also when compared to single D2 receptor mutants They indicated that a relatively long observation period for locomotor activity is needed in D3 mutant mice because of their rapidly habituating hyperactivity .
D4 knockout mice show significantly reduced exploration behavior and rearing activity . Extent of improvement of locomotor activity is dramatically increased in D4 receptor-deficient mice than that of wild type of littermate following the administration of ethanol, cocaine, and amphetamine, indicating that knockout mice are more responsive to the locomotor stimulants than wild type . Falzone et al. described that the absence of D4 receptor increases avoidance behavior to unconditioned stimuli and does not impair behavioral reactions to fear-conditioned stimuli in two different approach/avoidance conflict paradigms . These results indicate that D4 receptor could play a pivotal role in the DAergic modulation of cortical signals triggered by environmental stimuli, because D4 receptor is physiologically expressed at highest levels in the prefrontal cortex and is the predominant D2-like receptor localized in this brain area.text/html2012-08-27T16:34:48+01:00http://www.webmedcentral.com/Mr. Rajeev K SinglaArtificial Enzymes
http://www.webmedcentral.com/article_view/3666
Artificial enzymes may be defined as the synthetic, organic molecule prepared to recreate/mimic the active site of an enzyme. The binding of a substrate close to functional groups in the enzyme causes catalysis by so called proximity effects. It is therefore possible to create similar catalysts from small molecule which will mimics the enzyme active sites. Since the artificial enzymes need to bind molecules, they are made based on the host molecule such as cyclodextrins, crown ethers or calixarene etc[1]. Living cells often synthesize complex molecules via multistep sequential reactions, each catalyzed by an enzyme. To allow all of the reactions to work well, nature uses “Compartmentalization” or “site isolation” through which the individual steps are spatially separated to optimize their action. The key to achieving site isolation in solution lay in the use of “star polymers”, macromolecules that are capable of being functionalized so that they can bind and encapsulate small catalytic molecules in their core, adjacent to the binding site for the “reactant.”[2-4] A number of artificial enzymes have been reported catalyzing various reactions with rate increases up to 103; this is nevertheless substantially lower than natural enzymes that typically causes rate increases above 106[1].
Acetylcholinesterase (acetylcholine ‘acetylhydrolase, EC 3.1.1.7) is a widely distributed en- zyme in excitable membranes of nerve and muscle. Its molecular properties are of particular interest because of its involvement in nerve impulse transmission . The enzyme catalyses the hydrolysis of acetylcholine to choline and acetate by means of a two-step process involving the formation of an acyl-enzyme intermediate . With few exceptions, the extraction of acetylcholinesterase from any tissue source releases -various molecular forms of the enzyme. The basis for such heterogeneity is not fully understood, but in part may relate to cellular location. It is widely suggested that the three main molecular forms correspond to three locations: intracellular, membrane bound and immobilized on basal lamina. Artificial enzyme concept can help us to identify the interaction between acetylcholinesterase activity and membrane potential by using artificial acetylcholine esterase membrane[5].text/html2013-07-03T10:40:00+01:00http://www.webmedcentral.com/Ms. Suzana HashimA validated RP-HPLC Method for Quantification of Alpha-tocopherol in Elaeis guineensis Leaf Extracts
http://www.webmedcentral.com/article_view/4275
Background: Elaeis guineensis (oil palm) is a tropical tree from the family Arecaceae. The tree is rich in vitamin E such as alpha-tocopherol, an essential antioxidant in the lipid phase of the human body. Objective: This study aims to develop a reverse phase HPLC method for determination of alpha-tocopherol in E. guineensis leaf extracts. Methods: This method was validated at 220 nm for linearity, precision, accuracy and the limits of detection and quantification. Linearity was in the range 0.2–100 µg/mL at R2 = 0.9999. Results: Precision was determined as relative standard deviation by considering the retention time and the peak area of the reference compound, and was found to be <0.1%, and <3.4%, respectively. Accuracy was determined as the percentage recovery of the reference compound at two levels and was in the range 96–105%. The limits of detection and quantification were found to be 0.56±0.03 µg/mL and 1.65±0.03 µg/mL, respectively. The method was successfully applied for quantification of alpha-tocopherol in the E. guineensis leaf extracts; the concentration in the ethanolic extract was 1.65% and in water extract was 0.01%. Conclusion: The developed method showed good linearity, precision, accuracy and high sensitivity. Hence, it may be applied in routine quantification of alpha-tocopherol in E. guineensis. Key words: Elaeis guineensis, alpha-tocopherol, RP-HPLCtext/html2024-03-26T03:11:15+01:00http://www.webmedcentral.com/Dr. Ezzuddin A OkmiDeterminants of the influence of calorie labels displayed on menus in restaurants and cafes among Adults in Saudi Arabia, 2023: a cross-sectional study
http://www.webmedcentral.com/article_view/5829
Introduction
Obesity is one of the leading risk factors for many chronic diseases. It is ranked as forth fourth most common risk factor for NCDs. In the European Region Overweight and obesity affect about 60% of adults according to World Health Organization(1)
The obesity prevalence in Saudi Arabia is 35% which is three times higher than the global prevalence. )2)
The Global Burden of the Diseases report stated that the health effects of high Body mass index (BMI) accounted for about 4 million deaths and 120 million disability-adjusted life-years worldwide in 2015. Moreover, the report found approximately two-thirds of the deaths that were related to high BMI. (3)
Calorie labeling in restaurants and cafes is an important way that provide customers with the informed knowledge that can help them choose healthier food choices. (4)
Some evidence demonstrates calorie restriction causes a 5–10% loss of weight. (5) In 2014, a study conducted in the UK, found that Calorie labeling may decrease weight by about 3.5 kg over 36 weeks. (6)
Therefore, investigating the factors that can determine the influence of using calorie information is very important in reducing the prevalence of obesity which is considered a leading risk factor for chronic diseases in Saudi Arabia. Although there are studies conducted on the effects of using Calorie labeling and lifestyle among the general adult population worldwide (4-18), the number of studies on the influence of calorie information utilization in the KSA is scant. Thus, our study is very important to determine the effects of factors related to sociodemographic and lifestyle , on the influence of Calorie labels displayed on menus in restaurants and cafes among the adult population in KSA, Saudi Arabia, 2023
We want to detect the determinants of the influence of Calorie labeling and how this influence can be predicted based on sociodemographic and lifestyle factors.
text/html2016-11-26T09:57:06+01:00http://www.webmedcentral.com/Dr. Robert A LodderEffect of BSN272 on Hyperlipidemia and Atherosclerosis in LDLr-/- Mice
http://www.webmedcentral.com/article_view/5230
This study was designed to compare the effects of D-tagatose with BSN272 on serum lipids and prevention of atherosclerosis in LDLr-/- mice. BSN272 is a combination drug of D-tagatose and polydatin (trans piceid). LDLr-/- mice were divided into four groups and were all fed a standard chow. Mice were dosed by gavage and received water (group 1), a glucose/fructose mixture (group 2), or glucose/fructose mixture with D-tagatose (group 3) or with BSN272 (group 4) for a period of 9 weeks. Food intake, body weight, serum cholesterol, triglyceride and lipoprotein concentrations, and aortic atherosclerosis were measured. Cholesterol and triglyceride levels in the BSN272 treated group were consistently lower than in the water and glu/fruc groups throughout the course of the experiment. BSN272 reduced atherosclerotic lesions by 57% in LDLr-/- mice and significantly reduced VLDL and LDL cholesterol by 35 and 17%, respectively. From these results we conclude that the BSN272 combination is the most effective of the treatments for lowering cholesterol and triglycerides and for inhibiting the development of atherosclerosis.text/html2018-11-12T07:07:51+01:00http://www.webmedcentral.com/Dr. Robert A LodderCharacterization of BSN175: A Drug to Treat Prader-Willi Syndrome
http://www.webmedcentral.com/article_view/5519
The purpose of this research is to choose the best analytical method for determining stability of BSN175. This research uses an accelerated stability study to compare the decomposed and stable drug using IR and 1H NMR spectroscopy. The Bootstrap Error-adjusted Single-sample Technique (BEST) was used to compare the effectiveness of these analytical methods and choose the best option for determining stability.
A complete version of this article with figures is available on BioRXiv as BIORXIV/2018/448555.