A simple, precise, accurate and rapid high-performance thin-layer chromatographic method has been developed and validated for the estimation of atorvastatin calcium and ezetimibe simultaneously in combined dosage forms. The stationary phase used was precoated silica gel 60F ₂₅₄ . The mobile phase used was a mixture of chloroform: benzene: methanol: acetic acid (6.0:3.0:1.0:0.1 v/v/v/v). The detection of spots was carried out at 250 nm. The method was validated in terms of linearity, accuracy, precision and specificity. The calibration curve was found to be linear between 0.8 and 4.0 µg/spot for atorvastatin calcium and 0.1 and 1.0 µg/spot for ezetimibe. The limit of detection and the limit of quantification for atorvastatin calcium were found to be 170 ng/spot and 570 ng/spot respectively, and for ezetimibe, 20 ng/spot and 70 ng/spot respectively. The proposed method can be successfully used to determine the drug content of marketed formulation.

[ABSTRACT]  [FULL TEXT]  [PDF] [CITATIONS]

The antibacterial activities of 100 extracts of 50 Indian plant species were tested against six medically important bacterial strains, viz., B. cereus, S. aureus, S. epidermidis, K. pneumoniae, A. fecalis and P. aeruginosa . The antibacterial assay was done by both agar disc diffusion method and agar well diffusion method. The antibacterial activity exhibited by alcoholic extract was better than the aqueous extract. The results evaluated as the diameter of the inhibition zone of microbial growth showed that the extracts were more active against gram-positive bacteria than gram-negative bacteria. Amongst the investigated microorganisms, the most resistant bacteria were P. aeruginosa and A. fecalis . The most susceptible bacteria were gram-positive B. cereus and gram-negative K. pneumoniae , and the maximum activity was shown by T. chebula, M. indica and E. citriodora

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A simple, specific, accurate and precise reverse-phase high-performance liquid chromatographic method was developed for the simultaneous determination of atorvastatin calcium and amlodipine besylate in tablet dosage forms. A phenomenex Luna C-18, 5 µm column having 250 × 4.6 mm i.d. in isocratic mode, with mobile phase containing methanol: acetonitrile: 50 mM KH ₂ PO ₄ (20:50:30; pH 3.5) was used. The flow rate was 1.0 ml/min and effluent was monitored at 240 nm. The retention time of atorvastatin calcium and amlodipine besylate was 7.6 min and 3.2 min respectively. The linearity for atorvastatin calcium and amlodipine besylate was in the range of 5-120 µg/ml and 5-100 µg/ml respectively. The proposed method is accurate, precise, specific and rapid for simultaneous estimation of atorvastatin calcium and amlodipine besylate in tablets.

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In the present work an attempt has been made to carry out screening for the preliminary antibacterial activity of different plants used in Indian folk medicine. The aim of the study was to select an active plant extract which may be useful in developing new lead compounds to combat deadly diseases. Twelve plants were selected for preliminary screening for their antibacterial potentiality, viz., Abutilon indicum L., Acorous calamus L., Ammania baccifera L., Argyrea nervosa Burm. F., Bauhinia variegata L., Crataeva religiosa Forst., Hedychium spicatum L., Holarrhena antidysenterica L., Piper nigrum L., Plumbago zeylanica L., Psoralea corylifolia L., Saussurea lappa Costus. The antibacterial activity was done by both agar disc diffusion method and agar well diffusion method against five bacterial strains, viz., Bacillus cereus, Staphylococcus aureus, Klebsiella pneumoniae, Escherichia coli, Pseudomonas pseudoalcaligenes . The plant material was extracted with distilled water (aqueous) and methanol. The preliminary screening experiment revealed that methanol extracts were more potent than the aqueous extracts. The plant extracts were more active against gram-positive bacteria than gram-negative bacteria. The most susceptible bacteria were K. pneumoniae and the most resistant bacteria were E. coli . Bauhinia variegata L. exhibited remarkable antibacterial activity.

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A simple, accurate and precise high performance thin layer chromatographic method has been developed for the estimation of ofloxacin and ornidazole simultaneously in tablet dosage form. The method employed silica gel 60GF254 precoated plates as stationary phase and a mixture of n-butanol: ethanol: ammonia (5:5:4 %v/v/v) as mobile phase. The plate was scanned and quantified at 295 nm using Camag TLC scanner. The method was validated for linearity, accuracy, precision, repeatability and specificity, proving its utility in estimation of ofloxacin and ornidazole in combined dosage form.

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Over the past three decades intensive efforts have been made to design novel systems able to deliver the drug more effectively to the target site. The ongoing intense search for novel and innovative drug delivery systems is predominantly a consequence of the well-established fact that the conventional dosage forms are not sufficiently effective in conveying the drug compound to its site of action and once in the target area, in releasing the active agent over a desired period of time. The potential use of macromolecular prodrugs as a means of achieving targeted drug delivery has attracted considerable interest in recent years. Macromolecules such as antibodies, lipoproteins, lectins, proteins, polypeptides, polysaccharides, natural as well as synthetic polymers offer potential applicabilities as high molecular weight carriers for various therapeutically active compounds. Dextrans serve as one of the most promising macromolecular carrier candidates for a wide variety of therapeutic agents due to their excellent physico-chemical properties and physiological acceptance. The present contribution attempts to review various features of the dextran carrier like its source, structural and physico-chemical characteristics, pharmacokinetic fate and its applications as macromolecular carrier with special emphasis on dextran prodrugs.

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2-Acetylnaphtho[2,1- b ]furan (1), obtained from 2-hydroxy-1-naphthaldehyde was converted into 2-bromoacetylnaphtho[2,1- b ]furan (2), which served as an intermediate for the synthesis of title compounds. The compound (2) was treated with thiourea to get 2-(2-aminothiozol-4-yl)naphtho[2,1- b ]furan (3), which produced 2-(2-arylideneaminothiozol-4-yl)naphtho[2,1- b ]furans (4a-i) on reacting with various aromatic aldehydes. Schiff bases (4a-i) yielded 2-[2-(2-aryl-4-thiazolidinone)thiazol-4-yl]naphtho[2,1- b ]furans (5a-i) on treating with thioglycolic acid. Compound (2) was reacted with different aromatic amines to obtain 2-(N-aryl-2-amino)acetylnaphtho[2,1- b ]furans (6a-k). Similarly reaction with substituted thiourea furnished 2-(2-N-arylaminothiazol-4-yl)naphtho[2,1- b ]furans (7a-k). All the newly synthesized compounds have been characterized by elemental analysis and spectral data, which have been screened for antimicrobial and anthelmintic activities. The selected compounds have been evaluated for antiinflammatory and diuretic activities.

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Buccoadhesive buccal delivery systems for isosorbide dinitrate in the form of unidirectional buccal films were developed and characterized for improving bioavailability. The films were formulated by solvent casting method using different bioadhesive polymers like Carbopol 934P and polyvinyl pyrrolidone by using two different plasticizers propylene glycol and diethyl phthalate. Unidirectional release was achieved by preparing composite films with backing membrane. The films were characterized on the basis of their physical characteristics, bioadhesive performance, and other parameters. In vitro studies revealed that release rate of isosorbide dinitrate was higher from carbopol films containing ratio of Eudragit RL100 and polyvinyl pyrrolidine in proportion of 1:2 and 2:1, respectively by using both plasticizers. Drug diffusion from buccal films showed apparently zero order kinetics and release mechanism was diffusion controlled after considerable swelling. All the films exhibited sufficient in vitro bioadhesion strength. Promising formulations were further studied for temperature dependent stability studies. Results of our preliminary experiments indicate that, therapeutic level of isosorbide dinitrate can be achieved using this buccaladhesive formulation.

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A pH sensitive multi-particulate system intended to approximate the chronobiology of angina pectoris is proposed for colonic targeting. The system comprising of Eudragit S-100 coated pellets was designed for chronotherapeutic delivery of diltiazem hydrochloride. The drug loaded core pellets were produced by aqueous extrusion spheronization technique using microcrystalline cellulose as a spheronizing aid and PVP K 30 as a binder. Different coat weights of Eudragit S-100 were applied to the drug loaded pellets in an automatic coating machine to produce the pH sensitive coated pellets. Scanning electron microscopy revealed that the core pellets were discrete, spherical, or oval with a slightly rough surface whereas the coated pellets were covered with a uniform and continuous acrylic film. Optical microscopic image analysis portrayed that the values of aspect ratio and pellet circularity were close to 1.0, indicating the core pellets were almost spherical in shape. The friability with glass spheres was below 1.0%, signifying the core pellets produced were sufficiently hard. In vitro dissolution studies of the coated pellets performed following pH progression method showed that the drug release from the coated pellets depended on the coat weights applied and pH of the dissolution media. Since, diltiazem hydrochloride is a drug, which exhibits a high solubility, it would be possible to minimize drug release from the coated pellets below pH 7.0, and effectively release the drug at colonic pH only with higher coat loads (15-20% weight gain).

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Matrix tablets of phenylpropanolamine were fabricated using karaya gum and guar gum, alone or in combination with other excipients. The tablets were evaluated for physical characteristics like hardness, weight variation, friability, swelling index and drug content. In vitro release of drug was performed in 0.1N HCl (pH 1.2) for 2 h and the rest of dissolution in phosphate buffer (pH 6.8). The effect of water-soluble (lactose) and water-insoluble (dicalcium phosphate) excipients on drug release was evaluated. All the physical characteristics of the fabricated tablets were within acceptable limits. The tablets with karaya gum exhibited greater swelling indices than those with guar gum. All the batches provided drug release over a period of 6 h. The level of matrix former in the tablets affects drug release. Incorporation of lactose or dicalcium phosphate influenced drug release, but at lower polymer levels only. A combination of karaya gum and guar gum exhibited more sustained release than individual gum.

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The poor bioavailability and therapeutic response exhibited by conventional ophthalmic solutions due to rapid precorneal elimination of drug may be overcome by the use of in situ gel-forming systems that are instilled as drops into the eye and undergo a sol-gel transition in the cul-de-sac. The present work describes the formulation and evaluation of an ophthalmic delivery system of an antibacterial agent, gatifloxacin, based on the concept of ion-activated systems. Sodium alginate was used as the gelling agent in combination with hydroxy propyl methyl cellulose (Methocel E50LV), which acted as a viscosity enhancing agent. The developed formulations were therapeutically efficacious, stable, non-irritant and provided sustained release of the drug over an eight hour period. The developed system is thus a viable alternative to conventional eye drops.

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Chemical investigation of Crataeva nurvala leaves resulted in the isolation of four compounds, which are dodecanoic anhydride, methyl pentacosanoate, kaemferol-3-O-α-D-glucoside and quercitin-3-O-α-D-glucoside. Dodecanoic anhydride and methyl pentacosanoate are being reported for the first time from this plant. Kaemferol-3-O-α-D-glucoside and quercitin-3-O-α-D-glucoside have already been reported from this plant.

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A simple, precise, accurate and rapid high performance thin layer chromatographic method has been developed and validated for the determination of etoricoxib in dosage forms. The stationary phase used was precoated silica gel 60F ₂₅₄ . The mobile phase used was a mixture of chloroform: methanol: toluene (4:2:4 v/v). The detection of spot was carried out at 289 nm. The calibration curve was found to be linear between 100 to 600 ng/spot for etoricoxib. The proposed method can be used to determine the drug content of marketed formulations.

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Two simple, specific, accurate and precise methods, namely, reverse phase high performance liquid chromatography and high performance thin layer chromatography were developed for estimation of carvedilol in bulk drug and pharmaceutical formulations. For the high performance liquid chromatography method, Lichrospher 100 C-18, 5 µm column consisting of 200×4.6 mm i.d. in isocratic mode, with mobile phase containing 50 mM KH ₂ PO ₄ buffer (pH 3.0±0.1): acetonitrile: methanol (60:50:10 v/v/v) was used. The flow rate was 1.0 ml/min and effluent was monitored at 242 nm. The retention time was 4.56±0.03 min. For the high performance thin layer chromatography method a Camag high performance thin layer chromatography system comprising of Linnomat V automatic sample applicator, Hamilton Syringe, Camag TLC Scanner-3, Camag Win CAT software with stationary phase precoated silica gel 60F ₂₅₄ and mobile phase consisting of ethyl acetate: toluene: methanol (1:4:3.5 v/v/v). The detection of spot was carried out at 242 nm. The Rf value was 0.65±0.02. The methods were validated in terms of linearity, accuracy and precision. The linearity curves were found to be linear over 1-35 µg/ml for high performance liquid chromatography and 50-300 ng/spot for high performance thin layer chromatography. The limit of detection and limit of quantification for high performance liquid chromatography were found to be 0.2 and 0.85 µg/ml, respectively, and for high performance thin layer chromatography, 10 and 35 ng/spot, respectively. The proposed methods were successfully used to determine the drug content of marketed formulations.

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Rapid, precise, accurate, and specific ratiospectra derivative spectrophotometry and a simple UV spectrophotometry using simultaneous equation methods are developed for the simultaneous determination of bisoprolol fumarate and hydrochlorothiazide from combined pharmaceutical dosage forms. For ratiospectra derivative spectrophotometry, the amplitudes were measured at 202.6 nm for bisoprolol fumarate and the difference in amplitudes at 212.6 and 230 nm were measured for the determination of hydrochlorothiazide. In the simultaneous equation method, the signals were measured at 223 nm and 271.6 nm. Concentration of each drug was obtained by using the absorptivity values calculated for the drugs at two wavelengths, 223 and 271.6 nm. Commercial tablet formulations were successfully analyzed using the developed methods.

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2-Hydroxy-1-naphthonitrile (1) on treatment with different α-haloketones affords corresponding 2-acyl-3-aminonaphtho[2,1- b ]furans (2a-2d). The compounds 2a-2d on reacting with ammonium thiocyanate and benzoyl chloride produce N-acyl-N1-(2-acylnaphtho[2,1- b ] furan)thiourea (3a-3d), which on further refluxing with sodium hydroxide yield 2-mercapto-4-acylnaphtho[2,1- b ]furo[3,2-d]pyrimidines (4a-4d). These on stirring with chloroacetic acid give S-(4-acylnaphtho[2,1- b ]furo[3,2-d]pyrimidine)-mercaptoacetic acid (5a-5d). The structures of newly synthesized compounds have been established by elemental analysis and spectral studies. In addition, they have been screened for antimicrobial, diuretic, and antiinflammatory activities. The compounds 4c, d, 5c and 5d were found to be active against bacteria and fungi. The compounds 4c, 5a, 5c, and 5d showed significant diuretic activity having T/S values of 0.89, 0.68, 0.62, and 0.68, respectively. The compounds 5c and 5d showed considerable antiinflammatory activity having percentage protection value of 55.64 and 63.7.

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Two simple, accurate, and precise methods for simultaneous estimation of tramadol hydrochloride and chlorzoxazone in combined dosage form have been described. The first method employs formation and solving of simultaneous equations using 272.20 and 248.30 nm as two analytical wavelengths. The second method is absorption ratio method, which uses 272.20 and 257.50 nm as two analytical wavelengths. Both the methods allow the simultaneous determination of tramadol hydrochloride and chlorzoxazone in concentration ranges employed for this purpose with the standard deviation of <1.0% in the assay of tablet.

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The present study was undertaken with an objective to find out the gelling potentials of a natural gum obtained from plant Moringa oleifera . The gum was extracted by using water as solvent and precipitated using acetone as non-solvent. Physical characteristics such as, solubility, swelling index, loss on drying, and pH were studied. Diclofenac sodium was used as model drug for the formulation of gels. Seven batches of drug loaded gels with concentration of mucilage ranging from 5.5, 6.0, 6.5, 7.0, 7.5, 8.0, and 8.5 were formulated by using glycerin as plasticizer and methyl paraben as preservative. The pH, viscosity, and in vitro diffusion profiles were studied. The gels prepared with 8.0% of mucilage were found to be ideal and comparable with a commercial preparation.

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Three simple, accurate and economic methods multicomponent, two wavelength and simultaneous equations using area under curve have been described for the simultaneous determination of gatifloxacin and ornidazole in tablet dosage form. Gatifloxacin shows absorption maximum at 287.5 nm and ornidazole shows absorption maximum at 319.5 nm in distilled water. Beer's law was obeyed in the concentration range of 2-20 µg/ml for gatifloxacin and 10-60 µg/ml for ornidazole. The methods allow rapid analysis of binary pharmaceutical formulation with accuracy. Results of analysis for three methods were validated statistically and by recovery studies and were found satisfactory.

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A new rapid, sensitive, simple, and cost-effective spectrofluorimetric method was developed for the estimation of gatifloxacin in bulk and pharmaceutical formulations. The relative fluorescence intensity of gatifloxacin in 10 mM hydrochloric acid (pH 2.0) was measured at excitation wavelength (λexc ) of 292 nm and emission wavelength (λem ) of 482 nm. Linearity range was found to be 20-160 ng/ml with regression equation, relative fluorescence intensity = 36.05 ´ concentration in ng/ml + 12.60 with regression coefficient (r ²) = 0.9998. The method was tested and validated for various parameters according to ICH guidelines and USP. The detection and quantitation limits were found to be 5.48 and 16.61 ng/ml, respectively. The results demonstrated that the procedure is accurate, precise, and reproducible (relative standard deviation <2%), while being simple and less time consuming. The method is applicable for the estimation of gatifloxacin in different dosage forms and the results are in good agreement with label claims.

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Ethanol extract of leaves and flavonoid (isolated from leaves extract) from Tephrosia purpurea were evaluated for hepatoprotective activity in rats by inducing hepatotoxicity with carbon tetrachloride. These fractions were administered orally at a dose of 100 mg/kg/day. Serum level of transaminases, alkaline phosphate, and total bilirubin were used as biochemical markers of hepatotoxicity. Histopathological changes in the liver were also studied. The results of the study indicated that the hepatoprotective activity was more in ethanolic extract of leaves than isolated flavonoid.

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Pressure is mounting on the pharmaceutical industry to reduce both the cost of drugs and the time to market. The large number of targets made available in the last decade has created a new area for technologies that can rapidly identify quality lead candidates. Virtual screening is one such technology that is gaining increasing importance in the drug discovery process. Virtual screening is a reliable and inexpensive method currently being employed as a complementary approach to high-throughput screening. Virtual screening can be adopted irrespective of the structural information of the target receptor. In the absence of structural data, virtual screening using pharmacophore-based search is a major in silico tool. However, when the structure of the receptor is available, virtual screening using both pharmacophore-based and docking techniques can be employed. Both of these methods can be synergistically integrated to improve the drug design and development process. In this article, we provide an overview of methods for virtual screening - in particular, docking and pharmacophore-based - along with commercial algorithms implementing these methods, and a successful example in this arena. Further, we enumerate the potential for patenting such kind of studies.

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DNA triple helices offer new perspectives towards oligonucleotide-directed gene regulation. Triple helix forming oligonucleotides, which bind to double-stranded DNA, are of special interest since they are targeted to the gene itself rather than to its mRNA product (as in the antisense strategy). However, the poor stability of some of these structures might limit their use under physiological conditions. Specific ligands can intercalate into DNA triple helices and stabilize them. This review summarizes recent advances in this field while also highlighting major obstacles that remain to be overcome, before the application of triplex technology to therapeutic gene repair can be achieved.

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Isolation of isomeric furocoumarins from the seeds of Psoralea corylifolia Linn. (Family Leguminosae) is being reported for the first time from the variety found in western Rajasthan. On the basis of physical and spectral parameters, i.e., UV, IR, NMR, mass and chemical reactions such as hydrolysis, alkali fusion and oxidation, they have been identified as 2H-furo[3',2'-g][1] benzopyran-2-one (1) and 2H-furo[2',3'-h] [1-] benzopyran-2-one (2).

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The present study was conducted to evaluate the hepatoprotective effects of the Centella asiatica extract in carbon tetrachloride-induced liver injury in rats. Sprague Dawley rats were treated with alcohol extract of Centella asiatica orally in two doses (20 and 40 mg/kg/day) for 3 mo along with intraperitoneal injection of carbon tetrachloride (1 ml/kg). Biochemical parameters such as serum total protein, albumin and marker enzymes (aspartate aminotransferase, alanine aminotransferase and alkaline phosphatase) were estimated both before and after the experiment. Histopathological studies of liver were also carried out to confirm the biochemical changes. Carbon tetrachloride-induced hepatotoxic effects were evident by a significant (p < 0.05) increase in the serum marker enzymes and a decrease in the total serum protein and albumin. Administration of extract of Centella asiatica effectively inhibited these changes in a dose-dependent manner; maximum effect was with 40 mg/kg. Histopathological examination of liver tissue corroborated well with the biochemical changes. Hepatic steatosis, hydropic degeneration and necrosis were observed in carbon tetrachloride-treated group, while these were completely absent in the treatment group. Centella asiatica extract exhibited hepatoprotective action against carbon tetrachloride-induced liver injury. This effect is attributed to the presence of asiaticoside (14.5%) in the extract.

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A simple and sensitive spectrophotometric method has been developed for the determination of fexofenadine hydrochloride in bulk and pharmaceutical dosage forms. The method is based on the chloroform-extractable pale yellow colour complex formed by the reaction of fexofenadine with bromothymol blue at pH 2.6. The chromogen can be estimated at 412 nm against a reagent blank. This method obeys Beer's law in the concentration range of 10-50 µg/ml of the drug. The optimum reaction conditions and other analytical parameters were also evaluated. The proposed method has been successfully applied to the analysis of bulk drugs and their dosage forms.

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The substituted 2-acetyl benzofurans on bromination gave substituted 2-(2-bromoacetyl) benzofurans 2a-f. These on reaction with thiourea, urea, thiosemicarbazide and semicarbazide in presence of sodium acetate under microwave irradiation resulted 3a-f, 4a-f, 5a-f and 6a-f respectively. The structures of newly synthesised compounds have been established by elemental analysis, spectral data and screened for antimicrobial, anthelmintic, antiinflammatory and analgesic activities.

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Three different methods for extraction of colchicine have been studied, and it was found that extraction with petroleum ether and chloroform was the best and most reliable method. The amount of colchicine in six different species of Gloriosa , viz., Gloriosa superba, Gloriosa rothchildiana, Gloriosa planti, Gloriosa lutea, Gloriosa casuariana and Gloriosa vuchuria , has been determined using high performance liquid chromatography. Of the six different species of Gloriosa considered for this study, Gloriosa planti exhibited the highest level of colchicines, followed by Gloriosa lutea, Gloriosa casuariana and Gloriosa superba . The relatively high colchicine content in the above-mentioned species of Gloriosa , these could be recommended as substitute plants for Colchicum for the alkaloid colchicine.

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Four dihydroxy flavone derivatives viz 5,3´-, 7,3´-, 2´,3´- and 2´,4´-dihydroxy flavones were evaluated for their antinociceptive response in doses ranging from 3 to 200 mg/kg (s.c). Antinociception in mice was studied employing acetic acid induced abdominal constrictions, formalin induced nociception and tail immersion assay procedures. Involvement of opioid mechanism in the antinociceptive action of dihydroxy flavones was investigated using naloxone in acetic acid assay. All the four tested dihydroxy flavones exhibited a significant, dose related antinociceptive response in these assay procedures. The inhibition of nociceptive response was more than 98% in acetic acid writhing assay and 100% in the chronic phase of formalin assay. Naloxone almost completely antagonized the antinociceptive response of the four-dihydroxy flavone compounds. In conclusion, all the four investigated dihydroxy flavones exhibited opioid mediated antinociceptive response in mice.

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Mucoadhesive tablets for buccal administration of nicotine were prepared as an alternative to the available nicotine dosage forms. Three types of tablets were developed each containing two mucoadhesive components (HPMC, K4M and sodium alginate), (HPMC, K4M and carbopol) (Chitosan and sodium alginate). For each of these types, batches were produced changing the quantity of polymers resulting in nine different formulations. The tablets were evaluated for release pattern, and mucoadhesive performance. Pharmacokinetic studies were conducted in smokers. A peak plasma concentration of 16.78±2.27 ng was obtained in two hours, which suggests potential clinical utility in nicotine replacement therapy.

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Proton pump inhibitors have revolutionized the management of acid-peptic disorders in recent years. They have a broadly similar mechanism of action and are extensively metabolized in the liver via cytochrome P450 2C19 and 3A4 enzymes. A wide inter-individual variability in pharmacokinetics due to polymorphism in cytochrome P450 2C19 has been demonstrated for the first-generation proton pump inhibitors. Since this report, cytochrome P450 2C19 related pharmacokinetics of proton pump inhibitors has been demonstrated in populations other than Indians. Hence, it was of interest to explore inter-individual variations in pharmacokinetics of proton pump inhibitors, i.e., pantoprazole, omeprazole, rabeprazole, and lansoprazole in healthy Asian Indian male subjects after oral administration of the respective formulations. In this report, the pharmacokinetics of four proton pump inhibitors were investigated after single oral dose administered to healthy Indian male subjects. The plasma concentration time profiles of subjects showed high inter-individual variations for all four proton pump inhibitors. Furthermore, the subjects can be classified in groups based on the various patterns of pharmacokinetic profiles. Subjects with higher concentrations of the drug can be grouped as apparent poor metabolizers of the drug and subjects with comparatively lower concentrations of the drug can be categorized as apparent extensive metabolizers of the drug. The mean pharmacokinetic parameters C _max , T _max , AUC _0-t , AUC _0-00 and t _1/2 for the various groups were statistically significantly different from each other. The results demonstrated that the phenotypic polymorphism and extent of variability in plasma concentration - time profiles of proton pump inhibitors in healthy Indian males were in line with the other populations. Moreover, this information will be helpful in deciding the dose regimens that take the differences in drug metabolic capacity into account as Klotz has already suggested that the lower dosage of pantoprazole should be given to patients of poor metabolizer group with severe liver impairment for the same pharmacodynamic response.

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The objective of the study was to obtain the pharmacokinetic data of two controlled release formulations of (75 mg) indomethacin and to compare the relative bioavailability of the test formulation (product B cetostearyl alcohol microspheres) with standard formulation (product A-Microcid®SR 75 mg capsule). A single dose randomized (4×2) complete cross over study of the indomethacin (75 mg) was carried out on 8 healthy albino sheep. The study was carried out on two separate occasions with a washout period of 2 weeks. Blood samples were collected at pre-determined time intervals. Plasma indomethacin concentrations and other pharmacokinetic parameters obtained were statistically analyzed. The results of the paired t-test for the comparison of pharmacokinetic data showed that there was no significant variation between the products A and B. Products did not show any significant difference between them with regard to the T _max , C _max , AUC _0-24 , AUC_o-oo, MRT, Ka, K_el , K _1/2 , 3.0 h, 2054 ± 55.78 ng/ml, 9637 ± 132.87 ng h/ml, 9870 ± 129.22 ng h/ml, 4.76 ± 0.10 h, 0.3812 ± 0.002 h ^-1, 0.2713 ± 0.004 h ^-1, 2.55 ± 0.03 h ^-1, respectively for product A and 3.5 h, 1929 ± 20.32 ng/ml, 8343 ± 40.04 ng h/ml, 8617 ± 46.88 ng h/ml, 4.98 ± 0.02 h, 0.3648 ± 0.002 h ^-1, 0.2427 ± 0.010 h ^-1, 2.86 ± 0.20 h ^-1 for product B. From the dissolution studies and in vivo bioavailability studies, it was concluded that the products A and B are bioequivalent.

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A high performance liquid chromatographic method is described for simultaneous estimation of amiodarone and its metabolite desethylamiodarone in plasma. After precipitation with acetonitrile, the separation of amiodarone, desethylamiodarone and internal standard was accomplished using reversed phase chromatography. The mobile phase, a combination of ammonium acetate (pH 3.5 adjusted with ortho phosphoric acid) and acetonitrile was run isocratically through a C18 analytical column. The UV detection was done at 242 and 247 nm for amiodarone and desethylamiodarone respectively. Analytical run time was 10 min. Mean recovery was 84% for 0.5 µg/ml concentrations. The assay exhibited good linear relationship between peak height ratios and plasma concentration. Quantification limit was at least 0.01 µg/ml of amiodarone and desethylamiodarone. Accuracy and precision were over the concentration range of 0.01-10 µg/ml. Assay was successfully applied to the measurement of amiodarone and its metabolite desethylamiodarone in human plasma of patients who were on long-term oral therapy on amiodarone.

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Cyclooxygenase-2 inhibitors of indomethacin ester derivative series were subjected to quantitative structure activity relationship analysis with an attempt to derive and understand a correlation between the biological activity as dependent variable and various descriptors as independent variables. Several statistical regression expressions were obtained using multiple linear regression analysis. The analysis resulted in the following 2-D equation, which suggests that, BA = (0.8098) MR + (-0.0385) FR(-0.7764) F(-5.8964), n = 20, r = 0.912, r² = 0.831, f = 7.133, t = 2.671, std = 0.64. The cyclooxygenase-2 inhibition by ester derivatives of indomethacin is highly correlated with the thermodynamic (MR) and sterimol (B5, L) parameters, which in turn describes the importance of steric effect, indicating that a lipophilic bulkier group width-wise is required for good biological activity. This study can help in rational drug design and synthesis of new selective cyclooxygenase-2 inhibitors with predetermined affinity.

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A simple extractive spectrophotometric determination of saccharin is described. The method is based on bromination of saccharin to form N-bromo derivative, which on reaction with potassium iodide liberates iodine, imparting yellow colour to the solution. On addition of surfactant cetyl trimethyl ammonium bromide, the intensity of yellow colour increases; it is then extracted in isoamyl alcohol. The absorption maximum was observed at 400 nm, and Beer's law was found to obey over the range 1.5-15 µg of saccharin per 50 ml final solution (0.03-0.3 ppm). The molar absorptivity and Sandell's sensitivity were found to be 4.76 × 10 ⁵ l mol ^-1 cm ^-1 and 3.8 × 10 ^-4 µg cm ^-2 respectively. The method is sensitive, reproducible and free from interferences of common ions and ingredients commonly present in food products and has been successfully applied in the determination of saccharin in food and pharmaceutical products.

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Piperazine and its salts are reacted with alcoholic p-benzoquinone and buffered at pH 5.4 to give a coloured product with maximum absorption at 516 nm. The piperazine base has a molar absorptivity of 0.96 × 10 ⁴ 1/mol/cm, and Beer's law is obeyed in the range of 4-20 µg/ml. When applied to two commercial preparations, the proposed method gave mean recoveries within 1%, and relative standard deviation was less than 1%.

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An high performance liquid chromatography method for simultaneous estimation of piperacillin and tazobactam was developed using Wakosil II, C18, 250 × 4.6 mm, 5 µm column, with mobile phase composition of methanol, phosphate buffer-pH 4 and acetonitrile in the ratio of 1:2:1 v/v/v with the flow rate of 1 ml/min and UV detection at 220 nm. The retention time for piperacillin and tazobactam was found to be 6.4 and 3.1 min respectively. Linearity was observed over the concentration range of 10-80 µg/ml for piperacillin and 2-10 µg/ml for tazobactam. Recovery was found to be 100.7-104.7% for piperacillin and 103.6-105.7% for tazobactam.

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Medicine information is the provision of unbiased, evidence-based and critically evaluated information about medicines. Medicine information pharmacists have a wide spectrum of activities, i.e., answering enquiries, proactive provision of information, adverse drug reaction reporting, provision of a medicine helpline for public, support for drug and therapeutic committees and training and education. Apart from these usual responsibilities, medicine information pharmacist now provides information to drug discovery and development departments in the pharmaceutical industry. This article illustrates various roles of medicine information in the pharmaceutical industry.

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