Showing papers in "Indian Journal of Pharmaceutical Sciences in 2010"

Pharmacological review on Centella asiatica: A potential herbal cure-all

Abstract: In recent times, focus on plant research has increased all over the world. Centella asiatica is an important medicinal herb that is widely used in the orient and is becoming popular in the West. Triterpenoid, saponins, the primary constituents of Centella asiatica are manly believed to be responsible for its wide therapeutic actions. Apart from wound healing, the herb is recommended for the treatment of various skin conditions such as leprosy, lupus, varicose ulcers, eczema, psoriasis, diarrhoea, fever, amenorrhea, diseases of the female genitourinary tract and also for relieving anxiety and improving cognition. The present review attempts to provide comprehensive information on pharmacology, mechanisms of action, various preclinical and clinical studies, safety precautions and current research prospects of the herb. At the same time, studies to evaluate the likelihood of interactions with drugs and herbs on simultaneous use, which is imperative for optimal and safe utilization of the herb, are discussed.

An overview of curcumin in neurological disorders.

Abstract: Curcumin, the principal curcuminoid found in spice turmeric, has recently been studied for its active role in the treatment of various central nervous system disorders. Curcumin demonstrates neuroprotective action in Alzheimer's disease, tardive dyskinesia, major depression, epilepsy, and other related neurodegenerative and neuropsychiatric disorders. The mechanism of its neuroprotective action is not completely understood. However, it has been hypothesized to act majorly through its anti-inflammatory and antioxidant properties. Also, it is a potent inhibitor of reactive astrocyte expression and thus prevents cell death. Curcumin also modulates various neurotransmitter levels in the brain. The present review attempts to discuss some of the potential protective role of curcumin in animal models of major depression, tardive dyskinesia and diabetic neuropathy. These studies call for well planned clinical studies on curcumin for its potential use in neurological disorders.

Hepatoprotective effect of methanol extracts of Zingiber officinale and Cichorium intybus.

Abstract: The present work was carried out to investigate the hepatoprotective effect of ginger, chicory and their mixture against carbon tetrachloride intoxication in rats. Carbon tetrachloride treatment significantly elevated the alanine aminotransferase, aspartate aminotransferase, alkaline phosphatase and gamma glutamyltransferase activities and the serum triglycerides and cholesterol concentration as compared to control group. It also increased RBCs counts and Hb concentration, total or differential leucocytes counts. However it decreased platelet counts, platelet distribution width, mean platelet volume, platelet larger cell ratio. Methanol extract of ginger (250 and 500 mg/kg) and chicory (250 and 500 mg/kg) given alone or mixed (1:1 wt/wt) significantly restored the carbon tetrachloride-induced alterations in the biochemical and cellular constituents of blood. No toxic symptoms were reported in doses up to 5 g/kg. Alkaloids and/or nitrogenous bases, carbohydrates and/or glycosides, tannins, flavonoids, saponins and unsaturated sterols and/or triterpenes are the main active constituents of their methanol extract. The hepatoprotective effect of ginger and chicory was also confirmed by the histopathological examination of liver tissue.

Antibacterial Activity of some Medicinal Mangroves against Antibiotic Resistant Pathogenic Bacteria.

Abstract: The antibacterial activity of the leaves and bark of mangrove plants, Avicennia marina, A. officinalis, Bruguiera sexangula, Exoecaria agallocha, Lumnitzera racemosa, and Rhizophora apiculata was evaluated against antibiotic resistant pathogenic bacteria, Staphylococcus aureus and Proteus sp. Soxhlet extracts of petroleum ether, ethyl acetate, ethanol and water were prepared and evaluated the antibacterial activity using agar diffusion method. Most of the plant extracts showed promising antibacterial activity against both bacterial species. However, higher antibacterial activity was observed for Staphylococcus aureus than Proteus sp. The highest antibacterial activity was shown by ethyl acetate of mature leaf extracts of E. agallocha for Staphylococcus aureus. All ethyl acetate extracts showed higher inhibition against S. aureus while some extracts of chloroform, ethyl acetate and ethanol gave inhibition against Proteus sp. None of the petroleum ether and aqueous extracts showed inhibition against Proteus sp. All fresh plant materials did also show more antibacterial activity against both bacterial strains than did dried plant extracts. Antibacterial activity of fresh and dried plant materials reduced for both bacterial strains with time after extraction. Since L. racemosa and A. marina gave the best inhibition for bacterial species, they were used for further investigations. Charcoal treated plant extracts of L. racemosa and A. marina were able to inhibit both bacterial strains more than those of untreated plant extracts. Phytochemical screening of mature leaf, bark of L. racemosa and leaf extracts of A. marina has been carried out and revealed that leaf and bark contained alkaloids, steroids, triterpenoids and flavonoids. None of the above extracts indicate the presence of saponins and cardiac glycosides. Separated bands of extracts by TLC analysis showed antibacterial activity against S. aureus.

Synthesis, characterization and biocidal activities of some schiff base metal complexes.

Abstract: Some new mixed ligand complexes (1-5) of type ML'B (M(II)=Mn(II), Co(II), Ni(II), Cu(II) and Zn(II); HL'= o-vanillidene-2-aminobenzothiazole; B= 1,10-phenanthroline) and Schiff base metal complexes of types (ML 2 ") (6-10) and (M 2 L") (11-15) (HL"= o-vanillidene-2-amino-N-(2-pyridyl)-benzene sulfonamide) were synthesized and characterized by elemental analysis and spectral (IR, 1 H NMR and 13 C NMR) studies. The free ligands and their metal complexes have been screened for their in vitro biological activities against bacteria, fungi and yeast. The metal complexes show more potent activities compared with Schiff base ligands.

In vitro evaluation of Terminalia arjuna on calcium phosphate and calcium oxalate crystallization

Abstract: Urinary stones are one of the oldest and the most common afflictions in humans. This disease has tormented humans since the earliest records of civilization. Ten percent of men and 3 % of women have a stone during their adult lives. Calcium containing stones are the most common comprising about 75 % of all urinary calculi, which may be in the form of pure calcium oxalate (50 %) or calcium phosphate (5 %) or a mixture of both (45 %). A number of plants have been mentioned in the Indian ayurvedic system, which plays a vital role in the inhibition of kidney stones. In the present study, the inhibitory potency of crude extracts or fractions of successive solvent extractions of Terminalia arjuna bark was evaluated on various stages of formation of calcium phosphate and on the growth of calcium oxalate monohydrate crystals in vitro. Results obtained indicated that Terminalia arjuna bark has the potential to inhibit the formation of both calcium phosphate and calcium oxalate crystals in vitro. Butanol fraction of Terminalia arjuna extract was the most effective in inhibiting formation of calcium phosphate and calcium oxalate crystals in vitro.

Assessment of prevalence and mortality incidences due to poisoning in a South Indian tertiary care teaching hospital

Abstract: WHO reports estimate poisoning as one of the most common causes of increased morbidity and mortality rate world-wide. Various agents such as pesticides, drugs have been used for intentional and accidental poisoning in different countries. In the Indian scenario, pesticides are the most commonly used poisoning agents. To assess the prevalence and mortality incidence rate due to various poisoning agents a retrospective and prospective study conducted over a period of nine months in a tertiary care teaching hospital. Retrospective data of poisoning cases was collected from the medical records section and the prospective data of poisoning cases was collected from the emergency and causality departments. A total of 1045 poisoning related admissions were identified during the period January 2005 to September 2008. Among them, 68.40% of cases were due to intentional poisoning and 31.60% were due to accidental poisoning. Of the poisoning related admissions, 84.4% of patients recovered, whereas in 7.6% of cases condition did not improve. Mortality rate was observed 4%. Intentional poisoning was observed more in male population (60.2%) in the age group of 18-29 years. Accidental poisoning was seen more in children in the age group of 1-3 years. Incidence of overall poisoning cases were high due to pesticides (39.5%) followed by medicines (26.1%), household products (22.1%), environmental poisoning (12.1%) and heavy metals (0.2%). It was observed that availability of centralised poison information centre and treatment protocols will improvise poison management practices in tertiary care hospitals by the clinicians.

Monoclonal Antibodies as Diagnostics; an Appraisal

Abstract: Ever since the development of Hybridoma Technology in 1975 by Kohler and Milstein, our vision for antibodies as tools for research for prevention, detection and treatment of diseases, vaccine production, antigenic characterization of pathogens and in the study of genetic regulation of immune responses and disease susceptibility has been revolutionized. The monoclonal antibodies being directed against single epitopes are homogeneous, highly specific and can be produced in unlimited quantities. In animal disease diagnosis, they are very useful for identification and antigenic characterization of pathogens. Monoclonal antibodies have tremendous applications in the field of diagnostics, therapeutics and targeted drug delivery systems, not only for infectious diseases caused by bacteria, viruses and protozoa but also for cancer, metabolic and hormonal disorders. They are also used in the diagnosis of lymphoid and myeloid malignancies, tissue typing, enzyme linked immunosorbent assay, radio immunoassay, serotyping of microorganisms, immunological intervention with passive antibody, antiidiotype inhibition, or magic bullet therapy with cytotoxic agents coupled with anti mouse specific antibody. Recombinant deoxyribonucleic acid technology through genetic engineering has successfully led to the possibility of reconstruction of monoclonal antibodies viz. chimeric antibodies, humanized antibodies and complementarily determining region grafted antibodies and their enormous therapeutic use.

In Vitro Anticancer Activity of the Root, Stem and Leaves of Withania Somnifera against Various Human Cancer Cell Lines.

Abstract: Withania somnifera Dunal know as Ashwagandha belong Solanaceae family. It is extensively used in most of the Indian herbal pharmaceuticals and nutraceuticals. The current study, evaluate in vitro cytotoxicity in 50% ethanol extract of root, stem and leaves of Withania somnifera against five human cancer cell lines of four different tissues i.e. PC-3, DU-145 (prostrate), HCT-15 (colon), A-549 (lung) and IMR-32 (neuroblastoma). Root, stem and leaves extracts showed cytotoxicity activity ranging 0-98% depending on the cell lines but maximum activity was found in 50% ethanol extract of leaves of Withania somnifera. Ethanol extract of leaves obtained from treatments T2, T3, T4 and T5 showed strong activity against PC-3 and HCT-15 with 80-98% growth inhibition, while the 50% ethanol extract of leaves from T1 treatment showed a minimum of 39% and T3 treatment showed a maximum of 98% growth inhibition against HCT-15. This investigation is the first report of the anticancer activity in various parts of Withania somnifera cultivated in fly ash amended soil.

Preparation and Characterization of Ethosomes for Topical delivery of Aceclofenac.

Abstract: The aim of present study was to prepare and characterized ethosomes of aceclofenac which may deliver the drug to targeted site more efficiently than marketed gel preparation and also overcome the problems related with oral administration of drug. The formulations were prepared with varying the quantity of ethanol 10-50% (v/v), lecithin 1-4% (w/v), propylene glycol 5-20% (v/v) and evaluated for their vesicle size, shape and surface morphology, entrapment efficiency and in vitro drug permeation study. Ethosomes of average size of 1.112 μm with a spherical shape bearing smooth surface were observed by transmission electron microscopy and surface electron microscopy. The maximum entrapment of ethosomes was 91.06±0.79%. Cumulative amount of drug permeated through the biological membrane was found to be in the range of 0.26±0.014 to 0.49±0.032 mg/cm 2 . Stability profile of prepared system was assessed for 45 days and the results revealed that very less degradation of drug was observed during storage condition.

Antioxidant and Antimicrobial Activity of Alpinia officinarum.

Abstract: Alpinia officinarum is a rhizome belonging to the family zingeberaeceae. Hydro alcoholic extract by hot and cold maceration and methanol extract by percolation process Qualitative phytochemical analysis of extract of Alpinia officinarum rhizome showed a majority of the compound including tannins, alkaloids, flavonoids and saponins. Hydroalcoholic extract prepared by hot maceration process was found to contain more phenol and flavonol and it was measured as 50.1 mg/g and 54.02 mg/g, respectively. All the three extracts showed moderate to potent antimicrobial activity against the Bacillus cereus, Staphylococcus aureas, Pseudomonas auroginosa, Escherichia coli. None of the extracts showed antifungal activity against Aspergillus niger and Candida albicans. All the three extracts showed a concentration dependent radical scavenging activity by inhibiting diphenylpicrylhydrazyl free radical at the same time hydroalcoholic extract prepared by hot maceration process showed better reducing and total antioxidant activity.

Formulation and evaluation of mucoadhesive buccal films of enalapril maleate.

Abstract: Enalapril maleate is used in the treatment of hypertension and angina pectoris. It shows low bioavailability due to high hepatic first pass metabolism. Hence the present work was undertaken to formulate mucoadhesive buccal films of enalapril maleate with an objective to improve therapeutic efficacy, patient compliance and the bioavailability. In the present study ten formulations of mucoadhesive drug delivery system of enalapril maleate were prepared as buccal films, by solvent casting technique. Sodium carboxymethylcellulose, hydroxylpropylmethylcellulose, hydroxyethylcellulose and polyvinyl pyrrolidone K-90 were used as mucoadhesive polymers. Prepared films were evaluated for their weight, thickness, surface pH, swelling index, drug content uniformity, in vitro residence time, folding endurance in vitro release and permeation studies. Films exhibited controlled release over more than 10 h in permeation studies. It was concluded that the films containing 20 mg of enalapril maleate in sodium carboxymethylcellulose 2% w/v and hydroxyethyl cellulose 2% w/v (formulation F5), showed good swelling, a convenient residence time and promising controlled drug release, thus can be selected for the development of buccal film for effective therapeutic uses.

A New Improved RP-HPLC Method for Assay of Rosuvastatin Calcium in Tablets.

Abstract: A reliable and sensitive isocratic stability indicating RP-HPLC method has been developed and validated for assay of rosuvastatin calcium in tablets and for determination of content uniformity. An isocratic separation of rosuvastatin calcium was achieved on YMC C8, 150×4.6 mm i.d., 5 μm particle size columns with a flow rate of 1.5 ml/min and using a photodiode array detector to monitor the eluate at 242 nm. The mobile phase consisted of acetonitrile: water (40:60, v/v) pH 3.5 adjusted with phosphoric acid. The drug was subjected to oxidation, hydrolysis, photolysis and thermal degradation. All degradation products in an overall analytical run time of approximately 10 min with the parent compound rosuvastatin eluting at approximately 5.2 min. Response was a linear function of drug concentration in the range of 0.5-80 μg/ml (r(2)= 0.9993) with a limit of detection and quantification of 0.1 and 0.5 μg/ml respectively. Accuracy (recovery) was between 99.6 and 101.7%. Degradation products resulting from the stress studies did not interfere with the detection of rosuvastatin and the assay is thus stability-indicating.

Spectrophotometric and HPLC methods for simultaneous estimation of amlodipine besilate, losartan potassium and hydrochlorothiazide in tablets

Abstract: Two UV-spectrophotometric and one reverse phase high performance liquid chromatography methods have been developed for the simultaneous estimation of amlodipine besilate, losartan potassium and hydrochlorothiazide in tablet dosage form. The first UV spectrophotometric method was a determination using the simultaneous equation method at 236.5, 254 and 271 nm over the concentration range 5-25, 10-50 and 5-25 mug/ml for amlodipine besilate, losartan potassium and hydrochlorothiazide, respectively. The second UV method was a determination using the area under curve method at 231.5-241.5, 249-259 and 266-276 nm over the concentration range of 5-25, 5-25 and 10-50 mug/ml for amlodipine besilate, hydrochlorothiazide and losartan potassium, respectively. In reverse phase high performance liquid chromatography analysis is carried out using 0.025 M phosphate buffer (pH 3.7):acetonitrile (57:43 v/v) as the mobile phase and Kromasil C18 (4.6 mm i.dx250 mm) column as stationery phase with detection wavelength of 232 nm linearity was obtained in the concentration range of 2-14, 20-140 and 5-40 mug/ml for amlodipine besilate, losartan potassium and hydrochlorothiazide, respectively. Both UV-spectrophotometric and reverse phase high performance liquid chromatography methods were statistically validated and can be used for analysis of combined dose tablet formulation containing amlodipine besilate, losartan potassium and hydrochlorothiazide.

Polymers for colon targeted drug delivery.

Abstract: The colon targeted drug delivery has a number of important implications in the field of pharmacotherapy. Oral colon targeted drug delivery systems have recently gained importance for delivering a variety of therapeutic agents for both local and systemic administration. Targeting of drugs to the colon via oral administration protect the drug from degradation or release in the stomach and small intestine. It also ensures abrupt or controlled release of the drug in the proximal colon. Various drug delivery systems have been designed that deliver the drug quantitatively to the colon and then trigger the release of drug. This review will cover different types of polymers which can be used in formulation of colon targeted drug delivery systems.

Development and evaluation of pharmacosomes of aceclofenac

Abstract: Pharmacosomes are amphiphilic lipid vesicular systems containing phospholipid complexes with a potential to improve bioavailability of poorly water soluble as well as poorly lipophilic drugs. To improve the water solubility, bioavailability and minimize the gastrointestinal toxicity of aceclofenac, its pharmacosomes were prepared. Aceclofenac was complexed with phosphatidylcholine (80%) in two different ratios (1:1 and 2:1) using conventional solvent evaporation technique. Pharmacosomes thus prepared were subjected to solubility and drug content evaluation, scanning electron microscopy, differential scanning calorimetry, X ray powder diffraction and in vitro dissolution study. Pharmacosomes of aceclofenac were found to be disc shaped with rough surface in scanning electron microscopy. Drug content was found to be 91.88% (w/w) for aceclofenac phospholipid complex (1:1) and 89.03% (w/w) aceclofenac-phospholipid complex (2:1). Differential scanning calorimetric thermograms and X ray powder diffraction datas confirmed the formation of phospholipid complex. Solubility and dissolution profile of the prepared complex was found to be much better than aceclofenac.

Medication error management around the globe: An overview

Abstract: Medical mistakes that include medication errors have raised concerns about medication safety. Due to high consumption of medicines and self-treatment by all, especially the aging population, the issue of proper medication use and safety is at the forefront of public health concerns globally. Each country has a different approach towards medication event monitoring that is compliant with its own health care system. This paper focuses on the efforts and endeavors of some of the countries around the world to create an efficient error reporting systems to ensure public safety. Our analysis indicates that there are established and effective medication vigilance systems in many developed countries. The different countries undertake activities which range from collecting information about prescriptions, surveying physicians about adverse drug events, and conducting sophisticated post-marketing surveillance studies. There is still need for such sophisticated system in India; however recent promising developments are occurring towards building a medication vigilance system. Development of these systems may eventually contribute to a global medication vigilance system, which could reduce concern with medication errors and safety.

Antidiabetic and Free Radicals Scavenging Potential of Euphorbia hirta Flower Extract.

Abstract: The present study was carried out to evaluate antidiabetic and in vitro free radicals scavenging effects of flower extract of Euphorbia hirta. The ethanolic and petroleum ether extracts (250 and 500 mg/kg) were orally tested for 21 days in alloxan induced diabetic mice and blood glucose level was measured with glucometer. Administration of extract resulted in significant reduction in serum cholesterol, triglycerides, creatinine, urea, alkaline phosphatase levels but high density lipoprotein levels and total proteins were found to be increased after treatments. Free radicals scavenging effect of ethanolic extract was also evaluated by various antioxidant assays, including 1, 1-diphenyl-2-picryl hydrazyl free radical scavenging activity, superoxide anion radical scavenging, nitric oxide scavenging, and reducing power assay. It was compared with standard antioxidants compounds such as butylated hydroxyl anisole and ascorbic acid. All the extracts showed antioxidant activity in all the tested methods.

Effect of formulation and processing variables on the characteristics of tolmetin microspheres prepared by double emulsion solvent diffusion method

Abstract: The aim of this study was to evaluate microencapsulated controlled release preparations of tolmetin sodium using ethylcellulose as a retardant material. Microspheres were prepared by using water-in-oil-in-oil (W/O 1 /O 2 ) double-emulsion solvent diffusion method, using different ratios of ethylcellulose to tolmetin sodium. Span 80 was used as the droplet stabilizer and n-hexane was added to harden the microspheres. The prepared microspheres were characterized for their micromeritic properties, drug content, loading efficiency, production yield, and particle size. Fourier transform infrared spectroscopy, differential scanning calorimetry, X-ray powder diffractometry and scanning electron microscopy were used to characterize microparticles. The in vitro release studies were performed in pH 1.2 and 7.4. The prepared microspheres were spherical in shape. The drug-loaded microspheres showed near to the theoretical of entrapment and release was extended up to 24. The X-ray diffractogram and differential scanning thermographs showed amorphous state of the drug in the microspheres. It was shown that the drug: polymer ratio, stirring rate, volume of dispersing medium and surfactant influenced the drug loading, particle size and drug release behavior of the formed microparticles. The results showed that, generally, an increase in the ratio of drug: polymer (0.5:1) resulted in a reduction in the release rate of the drug which may be attributed to the hydrophobic nature of the polymer. The in vitro release profile could be modified by changing various processing and formulation parameters to give a controlled release of drug from the microparticules. The release of tolmetin was influenced by the drug to polymer ratio and particle size and was found to be diffusion and erosion controlled. The best-fit release kinetic was achieved with Peppas model.

Antiinflammatory, Analgesic and Antipyretic Activities of Mimusops elengi Linn

Abstract: In the present study, 70% ethanol extract of Mimusops elengi Linn. bark was assessed for antiinflammatory, analgesic and antipyretic activities in animals. The antiinflammatory activity of ethanol extract of Mimusops elengi (200 mg/kg, p.o) was evaluated using carrageenan-induced paw edema and cotton pellet-induced granuloma models. Analgesic effect was evaluated using acetic acid-induced writhing and Eddy's hot plate models and antipyretic activity was assessed by Brewer's yeast-induced pyrexia in rats. The ethanol extract of Mimusops elengi (200 mg/kg, p.o) significantly inhibited the carrageenan-induced paw oedema at 3rd and 4th h and in cotton pellet model it reduced the transudative weight and little extent of granuloma weight. In analgesic models the ethanol extract of Mimusops elengi decreases the acetic acid-induced writhing and it also reduces the rectal temperature in Brewer's yeast induced pyrexia. However, Mimusops elengi did not increase the latency time in the hot plate test. These results show that ethanol extract of Mimusops elengi has an antiinflammatory, analgesic and antipyretic activity.

Synthesis of thiolated alginate and evaluation of mucoadhesiveness, cytotoxicity and release retardant properties.

Abstract: Modification of polymers by covalent attachment of thiol bearing pendant groups is reported to impart many beneficial properties to them. Hence in the present study, sodium alginate-cysteine conjugate was synthesized by carbodiimide mediated coupling under varying reaction conditions and the derivatives characterized for thiol content. The thiolated alginate species synthesized had bound thiol content ranging from 247.8±11.03-324.54±10.107 ΅mol/g of polymer depending on the reaction conditions. Matrix tablets based on sodium alginate-cysteine conjugate and native sodium alginate containing tramadol hydrochloride as a model drug were prepared and mucoadhesive strength and in vitro drug release from the tablets were compared. Tablets containing 75 mg sodium alginate-cysteine conjugate could sustain release of 10 mg of model drug for 3 h, whereas 90% of the drug was released within 1 h from corresponding tablets prepared using native sodium alginate. An approximately 2-fold increase in the minimal detachment force of the tablets from an artificial mucin film was observed for sodium alginate-cysteine conjugate as compared to native sodium alginate. In vitro cytotoxicity studies in L-929 mouse fibroblast cells studied using an MTT assay revealed that at low concentrations of polymer, sodium alginate-cysteine conjugate was less toxic to L-929 mouse fibroblast cell line when compared to native sodium alginate. Hence, thiolation is found to be a simple route to improving polymer performance. The combination of improved controlled drug release and mucoadhesive properties coupled with the low toxicity of these new excipients builds up immense scope for the use of thiolated polymers in mucoadhesive drug delivery systems.

Antioxidant Effect of Tinospora cordifolia Extract in Alloxan-induced Diabetic Rats.

Abstract: Many plants are claimed to possess antidiabetic and antioxidant activity. In practice, it is being increasingly recognized to be an alternative approach to modern medicine. This study assess the antioxidant capacity of Tinospora cordifolia stem methanol extract in daily oral administration of 500 mg/kg of body weight for 40 days in alloxan induced diabetic rats. The erythrocytes membrane lipid peroxide and catalase activity was increased where as the activities of superoxide dismutase, glutathione peroxidase were found to be decreased significantly (P<0.01) in alloxan-induced diabetic rats. The levels of lipid peroxide in liver of diabetic rats increased significantly (P<0.01) and catalase, superoxide dismutase, glutathione peroxidase in liver was significantly decreased in alloxan-induced diabetic rats, when compared to normal rats. After treatment of methanol Tinospora cordifolia stem extract brings back to normal (P<0.01) in the erythrocytes membrane and liver cell enzymes activities.

Non-wood Fibre Production of Microcrystalline Cellulose from Sorghum caudatum: Characterisation and Tableting Properties

Abstract: The microcrystalline cellulose is an important ingredient in pharmaceutical, food, cosmetic and other industries. In this study, the microcrystalline cellulose, obtained from the stalk of Sorghum caudatum was evaluated for its physical and tableting characteristics with a view to assessing its usefulness in pharmaceutical tableting. The microcrystalline cellulose, obtained from the stalk of Sorghum caudatum, obtained by sodium hydroxide delignification followed by sodium hypochlorite bleaching and acid hydrolysis was examined for its physicochemical and tableting properties in comparison with those of the well-known commercial microcrystalline cellulose grade, Avicel PH 101. The extraction yield of this microcrystalline cellulose, obtained from the stalk of Sorghum caudatum was approximately 19%. The cellulose material was composed of irregularly shaped fibrous cellulose particles and had a moisture content of 6.2% and total ash of 0.28%. The true density was 1.46. The flow indices showed that the microcrystalline cellulose, obtained from the stalk of Sorghum caudatum flowed poorly. The hydration, swelling and moisture sorption capacities were 3.9, 85 and 24%, respectively. Tablets resulting from these cellulose materials were found to be without surface defects, sufficiently hard and having disintegration time within 15 min. The study revealed that the microcrystalline cellulose, obtained from the stalk of Sorghum caudatum compares favourably with Avicel PH 101 and conformed to official requirement specified in the British Pharmacopoeia 1993 for microcrystalline cellulose.

Triterpenoids from Psidium guajava with Biocidal Activity.

Abstract: In continuation of our studies on the phytochemical investigation of medicinal plants available in the foothills of Darjeeling and Teri, we report herein the isolation of two triterpenoids betulinic acid and lupeol from the leaf extract of Psidium guajava and their potential antimicrobial and phytotoxic activities. All the structures of the isolated compounds were confirmed by spectral (IR, NMR) analysis and by comparison with the literature reports.

Development and validation of HPLC method for the determination of pregabalin in capsules

Abstract: A simple, precise, specific, and accurate reverse phase HPLC method has been developed for the determination of pregabalin in capsule dosage form. The chromatography was set on Hypersil BDS, C8, 150×4.6 mm, 5 μm column using photodiode array detector. The mobile phase consisting of phosphate buffer pH 6.9 and acetonitrile in the ratio of 95:05 with flow rate of 1 ml/min. The method was validated according to ICH guidelines with respect to specificity, linearity, accuracy, precision and robustness. Lower limit of quantification is 0.6 mg/l. The pregabalin sample solution was found to be stable at room temperature for about 26 h.

Multiparticulate system for colon targeted delivery of ondansetron.

Abstract: Targeted delivery of drugs to colon has the potential for local treatment of a variety of colonic diseases. The main objective of the study was to develop a multiparticulate system containing chitosan microspheres for the colon targeted delivery of ondansetron for the treatment of irritable bowel syndrome. This work combines pH-dependent solubility of eudragit S-100 polymers and microbial degradability of chitosan polymers. Chitosan microspheres containing ondansetron were prepared by emulsion cross linking method. The effect of process variables like chitosan concentration, drug-polymer ratio, emulsifier concentration and stirring speed were studied on particle size and entrapment efficiency of chitosan microspheres. In vitro drug release studies in simulated gastro intestinal fluids showed a burst drug release pattern in the initial hour necessitating microencapsulation around the chitosan microspheres. The optimized formulation was then subjected to microencapsulation with eudragit S-100 by solvent evaporation technique. The effect of different coat/core ratio on particle size, drug entrapment efficiency and in vitro drug release were studied. Formulation which contain 1:10 core/coat ratio released lesser amount of drug in the upper gastro intestinal conditions and so selected as best formulation and then subjected to in vitro drug release studies in presence of rat ceacal contents to assess biodegradability of chitosan microspheres in colon. In order to study the drug release mechanism in vitro drug release data was fitted into various kinetic models. Analysis of regression values suggested that the possible drug release mechanism was Peppas model.

Development and Evaluation of pH-Dependent Micro Beads for Colon Targeting.

Abstract: The purpose of this research was to develop and evaluate multiparticulates of alginate and chitosan hydrogel beads exploiting pH sensitive property for colon-targeted delivery of theophylline. Alginate and chitosan beads were prepared by ionotropic gelation method followed by enteric coating with Eudragit S100. All formulations were evaluated for particle size, encapsulation efficiency, swellability and in vitro drug release. In vitro dissolution studies performed following pH progression method demonstrated that the drug release from coated beads depends on coat weights applied and pH of dissolution media. Mechanism of drug release was found to be swelling and erosion-dependent. The studies showed that formulated alginate and chitosan beads can be used effectively for the delivery of drug to colon and a coat weight of 20% weight gain was sufficient to impart an excellent gastro resistant property to the beads for effective release of drug at higher pH values.

Stability Indicating RP-HPLC Method for Simultaneous Determination of Simvastatin and Ezetimibe from Tablet Dosage Form.

Abstract: A simple, specific and sensitive reverse phase high performance liquid chromatographic method was developed and validated for simultaneous determination of ezetimibe and simvastatin from pharmaceutical dosage forms. The method uses C18 ODS Hypersil column and isocratic elution. The mobile phase composed of acetonitrile:phosphate buffer (pH 4.5, 0.01M) in the ratio of 65:35 v/v was used at a flow rate of 1.0 ml /min. UV detector was programmed at 232 nm for first 10 min and at 238 nm for 10 to 20 min. All the validation parameters were in acceptable range. The developed method was effectively applied to quantitate amount of ezetimibe and simvastatin from tablets. The method was also applied suitably for determining the degradation products of ezetimibe and simvastatin.

Development and validation of a RP-HPLC method for estimation of montelukast sodium in bulk and in tablet dosage form

Abstract: The present work describes a simple, precise and accurate HPLC method for estimation of montelukast sodium in bulk and in tablet dosage form. The separation was achieved by using octadecylsilane column (C18) and acetonitrile:1 mM sodium acetate adjusted to pH 6.3 with acetic acid in proportion of 90:10 v/v as mobile phase, at a flow rate of 1.5 ml/min. Detection was carried out at 285 nm. The retention time of montelukast sodium was found to be 3.4 min. The limit of detection was found 1.31 μg/ml and limit of quantification 3.97 μg/ml. The accuracy and reliability of the proposed method was ascertained by evaluating various validation parameters like linearity (1-100 μg/ml), precision, accuracy and specificity according to ICH guidelines. The proposed method provides an accurate and precise quality control tool for routine analysis of montelukast sodium in bulk and in tablet dosage form.

Comparison and suitability of gel matrix for entrapping higher content of enzymes for commercial applications

Abstract: To check the suitability of enzyme entrapped beads for use in pharmaceutical industry, amylase enzyme was entrapped in agar/agarose, polyacrylamide gels and calcium alginate beads. Sodium alginate of 1% concentration was found to be best with respect to immobilization efficiency and calcium alginate beads so obtained were not much susceptible to breakage. When sodium alginate- amylase mixture was added from a height of about 20-30 cm. into CaCl(2) solution, size of beads was large at higher alginate concentration due to the increase in the size of droplet formation before entering into CaCl(2) solution. Enzyme entrapped polyacrylamide and agar/agarose gels were fragile and could not withstand repeated use whereas enzyme entrapped in large calcium alginate beads was used successfully for 50 cycles for the conversion of starch into product without much damage to the beads under stirring conditions. Amylase preparation was also mixed with urease, lysozyme and coimmobilized in large sized calcium alginate beads. These beads were used for 10 repeated cycles to check the conversion of substrates into their products by their respective enzymes and we concluded that an enzyme or mixture of two or three enzymes can be immobilized in the same large sized calcium alginate beads. This will save the additional cost of bioreactor, manpower, maintenance conditions required for the conversion of one drug into another using enzyme/s entrapped in large sized beads.