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1,2,4-triazole and Schiff bases are active against antimicrobial and antitubercular activities. Isoniazid itself reacts as antitubercular drug. The two dimensional quantitative structure activity relationship study was used to predicts the antitubercular activity of the synthetic derivatives. Two dimensional quantitative structure activity relationship generated model using partial least squares regression method which predict the statistically significant r²=0.8940, q²=0.8197, pred_r²=0.6675 and F test=50.6234. Two dimensional quantitative structure activity relationship generated equation of pMICs is denoted the antitubercular activity correlated with thermodynamic descriptor XAMostHydrophilic. Pharmacokinetic properties absorption, distribution, metabolism, excretion were also predicted which useful for design the derivatives. A designed derivatives of 1-(3-(substitutidene)amino)-5-(2,3,4,5-tetrafluoro-6-substitutedphenyl)-4H-1,2,4-triazol-4-yl)-3-(pyridin-4-yl)urea (B1-B10) were synthesized and spectrally evicted from fourier-transform infrared spectroscopy, 1H Nuclear magnetic resonance, 13C Nuclear magnetic resonance and Mass spectra as well as biologically evaluated against antitubercular and antimicrobial activities. From the biologically evaluated derivatives, compounds B2, B4, B7, B8, B9 and B10 were found to be active against the different antimicrobial species. Where as compound B2 also active against antitubercular species. [ABSTRACT FROM AUTHOR]

Curcumin, demethoxy curcumin and bis-demethoxy curcumin were isolated from the dried root powder of Curcuma longa through the combined application of flash chromatography and open column chromatography. Isolated constituents were identified using spectral methods. An analytical method was developed for simultaneous quantitative estimation of curcuminoids from fast dissolving tablets containing ethanolic extract of Curcuma sp., as an active ingredient. The separation was achieved in a C18 column using an isocratic mobile phase comprised of acetonitrile:water (aqueous phase containing 4 % v/v glacial acetic acid) (50:50 % v/v), with the flow rate set at 2.0 ml/min. The chromatogram was recorded at 425 nm, using a photodiode array detector. The developed analytical method was validated as per international conference on harmonisation guidelines. The developed analytical method was found to be linear in the concentration range of 5-120 µg/ml, precise and robust to minor modifications in selected chromatographic parameters. The average of recovery was found within the range of 98 %-102 %. Limit of detection and limit of quantification value for curcumin was determined to be 0.35 and 1.06, respectively. The tablets containing 100 mg Curcuma ethanolic extract were formulated using the directly compressible vehicle. Each tablet was found to contain 20.77 %±0.22 % w/w curcumin, 3.18 %±0.03 % w/w demethoxy curcumin and 0.33 %±0.006 % w/w bis-demethoxy curcumin when estimated using developed analytical method. [ABSTRACT FROM AUTHOR]

Epigallocatechin gallate is a potent phytomolecule with wide biological activity and is a class III drug. The therapeutic effect is limited, owing to poor stability and limited membrane permeability across the intestine. The aim of this study was to develop and evaluate colon-targeted microspheres of epigallocatechin gallate, using natural polymers. Water-in-oil emulsion crosslinking technique was used to prepare microspheres of epigallocatechin gallate using interpenetrating network of chitosan and gum acacia and glutaraldehyde was used as a crosslinking agent. Prepared microspheres were filled in capsules coated with Eudragit S100. The prepared microspheres were evaluated in vitro for preformulation studies, encapsulation efficiency, micromeritic properties, dissolution studies and stability studies. Fourier transform infrared spectroscopy and differential scanning calorimetry studies had proved that the drug and polymers are compatible. The good flow property of microspheres show that the microspheres are not aggregated. Scanning electron microscope micrographs of microspheres show a rough and folded surface morphology. The microspheres are spherical and uniform in shape. Formulations show good encapsulation efficiency. Formulation F1 to F6 show sustained release of drug for 10 h. The in vitro drug release of batch F1 to F6 were best explained by Higuchi models due to diffusion mechanism of drug release from polymeric matrix system. The selected formulation batch for a period of 3 mo at 40±2°/75±5 % RH show no significant changes. The current approach was helpful to develop polysaccharide based microspheres of epigallocatechin gallate to enhance colonic drug delivery. [ABSTRACT FROM AUTHOR]

This study was designed to evaluate the neuroprotective activity of ethanol extract of Pongamia pinnata stem bark in monosodium glutamate-induced neurotoxicity in rats. Neurotoxicity was induced by intraperitoneal injection of monosodium glutamate 2 g per kg body weight daily for 7 days. Ethanol extract of Pongamia pinnata stem bark (200 and 400 mg/kg) was administered orally after 1 h of monosodium glutamate treatment. Dextromethorphan (30 mg/kg, p.o.) was used as standard drug for the comparison. The degree of protection was determined by various behavioural, locomotor, muscle grip activity, lipid peroxidation and measurement of antioxidant status of glutathione, catalase and superoxide dismutase. Estimation of calcium, sodium and potassium ions in brain tissue and gamma aminobutyric acid level in serum was carried out. The histopathological study of brain tissue was also carried out. Treatment with Pongamia pinnata significantly improved monosodium glutamate-induced alteration in behavioural and locomotor activity and muscle strength. Significant decrease in lipid peroxidation and increase in glutathione, superoxide dismutase and catalase was observed in Pongamia pinnata treated group. Further, Pongamia pinnata also significantly reduced the monosodium glutamate-induced excitotoxicity by decreasing the level of Ca+2 and Na+ with concomitant increase in the level of K+. Serum gamma aminobutyric acid level was also increased in Pongamia pinnata treated animals. Further, the histopathological evidence supports the neuroprotective activity of Pongamia pinnata. In conclusion, the present study suggests that the ethanol extract of stem bark of Pongamia pinnata possesses significant neuroprotective activity in albino rats. [ABSTRACT FROM AUTHOR]

A novel series of chalcones, pyrimidines and imidazolinone is described; chalcones (4a-o) were prepared from the ead molecule 4-[2-(5-ethylpyridin-2-yl)ethoxy]benzaldehyde. Pyrimidine (5a-o) derivatives were prepared from the reaction of chalcones and guanidine nitrate in alkali media. Imidazolinones (6a-o) were synthesized from reaction of pyrimidine and oxazolone derivatives (prepared by Erlenmeyer azlactone synthesis). The structures of the synthesized compounds were assigned on the basis of elemental analysis, IR, ¹H and 13C NMR spectral data. All the products were screened against different strains of bacteria and fungi. Most of these compounds showed better inhibitory activity in comparison to the standard drugs. [ABSTRACT FROM AUTHOR]

A simple, sensitive and precise RP-HPLC method was developed for the determination of dutasteride in tablet dosage form. The RP-HPLC separation was achieved on phenomenex C18 column (250 mm, id 4.6 mm, 5 µm) using mobile phase methanol:water (90:10 v/v) at a flow rate of 1 ml/min at an ambient temperature. Quantification was achieved with photodiode array detection at 235 nm over the concentration range 1-12 µg/ml. The method was validated statistically and was applied successfully for the determination of dutasteride in tablets. [ABSTRACT FROM AUTHOR]

A single dose, crossover bioequivalence study of two different brands of clonidine hydrochloride 25 µg tablets was conducted in 24 (+2 stand by) healthy, adult, male, Indian subjects under fasting conditions to check the implication of enterohepatic re-circulation on assessment of bioequivalence. After an overnight fasting of at least 10 h, the subjects received single oral dose of test or reference product with either of the product as per randomization schedule in each period with a washout period of 10 days. The pre-dose blood sample was collected within a period of one h before dosing. The post-dose blood samples were collected at specified time intervals up to 96 h. The plasma concentrations of clonidine were quantified by validated LCMS/MS method and pharmacokinetic parameters were computed. The 90% confidence intervals of test/reference ratios for Cmax and area under the plasma-concentration- time-curve AUC under 0-t were found to be between 0.80 and 1.25 for log-transformed data. Analysis of variance did not show significant difference to these parameters. No meaningful values of Kel and therefore AUC under 0-infinity could be calculated for significant number of subjects due to enterohepatic re-circulation. Based on the results obtained, two different brands of clonidine 25 µg tablets have comparable rate and extent of absorption after oral administration but failed to show bioequivalence as per regulatory requirement of Food and Drugs Administration-united states. [ABSTRACT FROM AUTHOR]

A binary mixture of imipramine HCl and chlordiazepoxide was determined by three different spectrophotometric methods. The first method involved determination of imipramine HCl and chlordiazepoxide using the simultaneous equations and the second method involved absorbance ratio method. Imipramine has absorbance maxima at 251 nm, chlordiazepoxide has absorbance maxima at 264.5 nm and isoabsorptive point is at 220 nm in methanol. Linearity was obtained in the concentration ranges of 1-25 and 1-10 µg/ml for Imipramine HCL and Chlordiazepoxide, respectively. The third method involved determination of these two drugs using the first-derivative spectrophotometric technique at 219 and 231.5 nm over the concentration ranges of 1-20 and 2-24 µg/ml with mean accuracies 99.46±0.78 and 101.43±1.20%, respectively. These methods were successively applied to pharmaceutical formulations because no interferences from the tablet excipients were found. The suitability of these methods for the quantitative determination of the compounds was proved by validation. [ABSTRACT FROM AUTHOR]

A binary mixture of fluoxetine HCl and olanzapine was determined by two different methods. The first method involved determination of fluoxetine HCl and olanzapine using reversed-phase liquid chromatography using acetonitrile:methanol:0.032 M ammonium acetate buffer (45:05:50, v/v/v) as the mobile phase at a flow rate of 1.5 ml/min. Quantitation was achieved with ultraviolet detection at 235 nm over concentration ranges of 0.2-4 and 0.1-2 µg/ml; mean accuracies were 101.16±0.59 and 99.79±0.56% for fluoxetine HCL and olanzapine, respectively. The second method was based on the high performance thin layer chromatography separation of the two drugs followed by densitometric measurements of their spots at 235 nm. The separation was carried out on Merck TLC aluminium sheets of silica gel 60 F254 using acetone:methanol:triethyleamine (5:3:0.5, v/v/v), as mobile phase. The linearity was found to be in the range of 300-1000 and 150-500 ng/spot; mean accuracies were 100.95±0.52 and 99.31±0.51% for fluoxetine HCl and olanzapine, respectively. The method was successively applied to tablets because no chromatographic interferences from the tablet excipients were found. The methods retained their accuracy and precision when the standard addition technique was applied. The results obtained by applying the proposed methods were statistically analyzed. [ABSTRACT FROM AUTHOR]

A binary mixture of amitriptyline HCl and chlordiazepoxide was determined by three different methods. The first method involved determination of amitriptyline HCl and chlordiazepoxide using the first derivative spectrophotometric technique at 219 and 230 nm over the concentration ranges of 1-20 and 2-24 µg/ml with mean accuracies 100.9±0.87 and 99.2±1.0%, respectively. The second method was reversed-phase high performance liquid chromatography using methanol: acetonitrile: 0.065 M ammonium acetate buffer (50:20:30, v/v/v), final pH adjust to 5.5 ± 0.02 with ortho phosphoric acid as the mobile phase and was pumped at a flow rate of 1.0 ml/ min. Quantification was achieved with ultraviolet detection at 240 nm over concentration ranges of 0.25-4 and 0.1-1.6 µg/ml; mean accuracies were 100.55±0.62 and 100.71±0.81%, respectively. The third method utilized high performance thin layer chromatography method in tablet dosage form. The method was based on separation of the two drugs followed by densitometric measurements of their spots at 240 nm. The separation was carried out on Merck thin layer chromatographic aluminium sheets of silica gel 60 F254 using carbon tetrachloride: acetone: triethylamine (6:3:0.2, v/v/v) as mobile phase. The linearity was found to be in the range of 50-600 and 20-240 ng/spot for amitriptyline hydrochloride and chlordiazepoxide, respectively. The methods were successively applied to pharmaceutical formulation because no chromatographic interferences from the tablet excipients were found. The suitability of these methods for the quantitative determination of the compounds was proved by validation. [ABSTRACT FROM AUTHOR]

A rapid, selective and stability-indicating high performance thin layer chromatographic method was developed and validated for the simultaneous estimation of olanzapine and fluoxetine in combined tablet dosage form. Olanzapine and fluoxetine were chromatographed on silica gel 60 F254 TLC plate using methanol:toluene (4:2 v/v) as the mobile phase and spectrodensitometric scanning-integration was performed at a wavelength of 233 nm using a Camag TLC Scanner III. This system was found to give compact spots for both olanzapine (Rfvalue of 0.63±0.01) and fluoxetine (Rf value of 0.31±0.01). The polynomial regression data for the calibration plots showed good linear relationship with r²=0.9995 in the concentration range of 100-800 ng/spot for olanzapine and 1000-8000 ng/ spot for fluoxetine with r²=0.9991. The method was validated in terms of linearity, accuracy, precision, recovery and specificity. The limit of detection and the limit of quantification for the olanzapine were found to be 30 and 100 ng/spot, respectively and for fluoxetine 300 and 1000 ng/spot, respectively. Olanzapine and fluoxetine were degraded under acidic, basic and oxidation degradation conditions which showed all the peaks of degraded product were well resolved from the active pharmaceutical ingredient. Both drugs were not further degraded after thermal and photochemical degradation. The method was found to be reproducible and selective for the simultaneous estimation of olanzapine and fluoxetine. As the method could effectively separate the drugs from their degradation products, it can be employed as a stability-indicating method. [ABSTRACT FROM AUTHOR]

Floating tablets of carbamazepine were developed using melt granulation technique. Bees wax was used as a hydrophobic meltable material. Hydroxypropylmethylcellulose, sodium bicarbonate and ethyl cellulose were used as matrixing agent, gas-generating agent and floating enhancer, respectively. The tablets were evaluated for in vitro buoyancy and dissolution studies. A simplex lattice design was applied to investigate the combined effect of 3 formulation variables i.e. amount of hydroxypropyl methylcellulose (X1), ethyl cellulose (X2) and sodium bicarbonate (X3). The floating lag time (Flag), time required for 50% (t50) and 80% drug dissolution (t80) were taken as responses. Results of multiple regression analysis indicated that, low level of X1 and X2, and high level of X3 should be used to manufacture the tablet formulation with desired in vitro floating time and dissolution. Formulations developed using simplex lattice design were fitted to various kinetic models for drug release. Formulation S3 was selected as a promising formulation and was found stable at 40° and 75% relative humidity for 3 months. Present study demonstrates the use of simplex lattice design in the development of floating tablets with minimum experimentation. [ABSTRACT FROM AUTHOR]

Alternate copolymers of n-butyl methacrylate and maleic anhydride were prepared and characterized. Amoxycillin was bound on copolymers through pendent anhydride groups by chemical bonding. In vitro release rates were investigated in 0.1 M phosphate buffer solution with varying pH at 370 as well as in biological media. The release rates of the investigated model drug molecules followed first order kinetics and were dependent on buffer concentration and pH. It was observed that molecular weight of copolymers varied from 8000 to 22,000 g/mol and duration of the delay period prior to release increased from 6 to 9 d. P(BMA-MA-1) showed increase in cumulative release rate with increase in pH unit from 3.8 to 7.2, which further decreased from pH 7.8 and 8.0, respectively. With P(BMA-MA-2) gradual increase in release activity was observed in acidic range and in neutral to alkaline condition (pH 7.0 to 8.0) the release activity lasted for 7 to 9 d respectively. Similar condition for P(BMA-MA- 3) showed cumulative release activity for 9 d in acidic pH, which further decreased to 7 d from pH 7.0 to 8.0. P(BMA-MA-1, 2 and 3) showed maximum inhibition of 40%, 59.3% and 72.8% towards Bacillus subtilis, 40%, 44% and 65.4% inhibition against Staphylococcus aureus and 41.2%, 51.7% and 69.1% inhibition against Escherichia coli at 48 h of incubation. [ABSTRACT FROM AUTHOR]

A simple and sensitive high performance thin layer chromatography (HPTLC) method has been developed for the quantitative estimation of linezolid in its single component tablet formulations (600 mg). Linezolid was chromatographed on Silica Gel 60 F254 TLC plate using methanol: benzene (2:8 v/v) as mobile phase. Linezolid showed Rf value 0.45 ± 0.03 and scanned at 258 nm using a Camag TLC scanner 3. The method was validated in terms of linearity (200-1400 ng/spot), precision (intra-day variation, 0.75 to 1.26% and inter-day variation, 1.2 to 2.8%), accuracy (97.8 to 100.4%) and specificity. The limit of detection and limit of quantification for linezolid were found to be 16.7 ng/spot and 50.7 ng/spot, respectively. The developed method was successfully used for the assay of linezolid tablet formulations. The method was found to be simple, sensitive, specific, accurate and precise and can be used for the routine quality control testing of linezolid marketed formulations. [ABSTRACT FROM AUTHOR]

Plant products serve as an alternative to synthetic products because of local accessibility, eco-friendly nature and lower prices compared to imported synthetic products. Natural gums and mucilage have been widely explored as pharmaceutical excipients. The present study was undertaken to separate mucilage from the seeds of Ocimum americanum Linn. and explore its use as a tablet disintegrant. Methods for extraction of mucilage from the seeds were developed and the yield by the method C was found to be 14%. The mucilage was evaluated for various parameters as per Indian Pharmacopoeia. The loss on drying, ash value and microbial load were well within the official limits. The disintegrating efficiency of separated mucilage was compared with that of the starch in tablets prepared using lactose, propranolol hydrochloride and polyvinyl pyrrolidone as model diluent, drug and binder, respectively. The disintegration time for tablet formulations prepared using mucilage (10% w/w) was less (154 s) than that of the tablet formulations prepared using starch as a disintegrant (269 s). The mucilage not interfered with the release of a drug from tablet formulations. Formulated tablets were found stable at 45° C for 4 weeks without significant change in hardness, disintegration time and in vitro drug release. [ABSTRACT FROM AUTHOR]

The present investigation describes the influence of content of polyethylene oxide and ratio of lactose to starch 1500 on dipyridamole release from self correcting floating matrix tablets using 3² full factorial design. Tablets were evaluated for in vitro floating ability and drug release study using USP 24 type II apparatus using 0.1 N HCI at 100 rpm and temperature of 37±0.5°. Multiple regression analysis and two way analysis of variance followed by Tukey test were performed for dependent variables. All formulations floated within 2 min regardless of factors studied and had total floating time of more than 12 h. It was observed that both the factors had significant influence on all dependent variable studied (<0.05) except the ratio of lactose to starch 1500 did not significantly contribute for Q1 (>0.05). As content of polymer increased the release rate declined with increase in value of diffusion exponent giving anomalous drug release to zero order drug release (<0.05). It was observed that above a certain threshold level of polymer content further increase did not contribute significantly for percentage drug release. Lactose gave higher drug release with release mechanism towards zero order compared to starch 1500 which gave slower release with release mechanism towards diffusion based. Although both the factors significantly contribute for percentage drug release at different time point, the content of polymer dominated. It was observed that polymer content was a dominant controlling factor for drug release kinetics and it could be controlled by employing various blends of fillers. [ABSTRACT FROM AUTHOR]

A simple, precise, accurate and rapid high performance thin layer chromatographic method has been developed and validated for the simultaneous estimation of irbesartan and hydrochlorothiazide in combined dosage forms. The stationary phase used was precoated silica gel 60F254. The mobile phase used was a mixture of acetonitrile: chloroform: glacial acetic acid (7:3:0.1 v/v/v). The detection of spots was carried out at 260 nm. The method was validated in terms of linearity, accuracy, precision and specificity. The calibration curve was found to be linear between 100 to 700 ng/spot for irbesartan and 100 to 350 ng/spot for hydrochlorothiazide. The limit of detection and the limit of quantification for the irbesartan were found to be 30 and 100 ng/spot respectively and for hydrochlorothiazide 25 and 100 ng/spot respectively. The proposed method can be successfully used to determine the drug content of marketed formulation. [ABSTRACT FROM AUTHOR]

Present investigation describes statistically the influence of viscosity of hydroxypropyl methylcellulose and types of filler on dipyridamole release from floating matrix tablets using 32 full factorial design. Tablets were prepared using direct compression technique. Tablets were evaluated for in vitro floating ability and drug release study using USP 24 types II paddle apparatus using 0.1 N HCl (pH 1.2) at rotation of 100 rpm and temperature of 37±0.5°. Multiple regression analysis was performed for dependent variables studied and to evaluate contribution of factors with their levels two way ANOVA was performed followed by Tukey test. Polynomial equations and response surface plots were generated for all dependent variables. It was observed that both the factors had significant influence on all dependent variable studied (p<0.05). It was observed that as viscosity of polymer increases the release rate constant was decreased. Release rate obtained was highest when microcrystalline cellulose was employed as filler followed by dicalcium phosphate and lactose. Mechanism of drug release was anomalous types and depends upon viscosity of polymer and types of filler used. Microcrystalline cellulose gave release mechanism nearer to diffusion mechanism while dicalcium phosphate and lactose gave anomalous release. It was observed that both the factors had significant contribution on all dependent variables studied. A major controlling factor for kinetics of drug release was viscosity of polymer and it can be modified by incorporation of different types of filler. In initial phase of drug release viscosity of polymer and types of filler both governs the drug release while in later phase only the viscosity of polymer predominates. [ABSTRACT FROM AUTHOR]

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 60F254. 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 FROM AUTHOR]

A binary mixture of trifluoperazine HCl and chlordiazepoxide was determined using reversed-phase liquid chromatography method using methanol:water (97:03, v/v) pumped at a flow rate of 1.0 ml/min. Quantification was achieved with ultraviolet detection at 262 nm over concentration ranges of 0.1-1 and 0.5-5 µg/ml; mean accuracies were 101.05±0.47 and 98.97±0.33 %, respectively. The method was successively applied to tablet dosage forms as no chromatographic interferences from the tablet excipients were observed. The method retained its accuracy and precision when the standard addition technique was applied. [ABSTRACT FROM AUTHOR]

A simple, precise, accurate and rapid high performance thin layer chromatographic method has been developed and validated for the simultaneous estimation of valsartan and hydrochlorothiazide in combined dosage forms. The stationary phase used was precoated silica gel 60F254. The mobile phase used was a mixture of chloroform: methanol: toluene: glacial acetic acid (6:2:1:0.1 v/v/v/v). The detection of spots were carried out at 260 nm. The method was validated in terms of linearity, accuracy, precision and specificity. The calibration curve was found to be linear between 300 to 800 ng/spot for valsartan and 100 to 600 ng/spot for hydrochlorothiazide. The limit of detection and the limit of quantification for the valsartan were found to be 100 and 300 ng/spot respectively and for hydrochlorothiazide 30 and 100 ng/spot respectively. The proposed method can be successfully used to determine the drug content of marketed formulation. [ABSTRACT FROM AUTHOR]

Simple, specific, accurate and precise method, namely, reverse phase high performance liquid chromatography was developed for estimation of duloxetine HCl in pharmaceutical formulations. For the high performance liquid chromatography method, Phenomenox C-18, 5 µm column consisting of 250x4.6 mm i.d. in isocratic mode, with mobile phase containing 0.01M 5.5 pH phosphate buffer: acetonitrile (60:40 v/v) and final pH adjust to 5.5±0.02 with phosphoric acid was used. The flow rate was 1.2 ml/min and effluent was monitored at 231 nm. The retention time was 5.61 min. The method was validated in terms of linearity, accuracy and precision. The linearity curve was found to be linear over 0.25-4 µg/ml. The limit of detection and limit of quantification were found to be 0.10 and 0.25 µg/ml respectively. The proposed method was successfully used to determine the drug content of marketed formulations. [ABSTRACT FROM AUTHOR]

A simple, precise, accurate and rapid high performance thin layer chromatographic method has been developed and validated for the estimation of olmesartan medoxomil and hydrochlorothiazide simultaneously in combined dosage forms. The stationary phase used was precoated silica gel 60F254. The mobile phase used was a mixture of acetonitrile:chloroform:glacial acetic acid (7:2:0.5, v/v/v). The detection of spots was carried out at 254 nm. The method was validated in terms of linearity, accuracy, precision and specificity. The calibration curve was found to be linear between 500 to 750 ng/spot for olmesartan medoxomil and 100 to 600 ng/spot for hydrochlorothiazide. The limit of detection and the limit of quantification for the olmesartan medoxomil were found to be 170 and 500 ng/spot, respectively and for hydrochlorothiazide 30 and 100 ng/spot, respectively. The proposed method can be successfully used to determine the drug content of marketed tablet formulation. [ABSTRACT FROM AUTHOR]

Swetiamarin is one of the phytoconstituents present in Enicostemma littorale Linn. Enicostemma littorale is known for its hypoglycemic activity from ancient times. In the present study an attempt has been made to develop a HPTLC method for quantitative estimation of swetiamarin in plants and different marketed antidiabetic polyherbal formulations. This HPTLC method was found to be reproducible, accurate and precise and could detect swetiamarin concentration at nanogram level. The developed HPTLC method would be an important tool in the way of acceptability of quality control method of polyherbal formulations. [ABSTRACT FROM AUTHOR]

A simple, precise, accurate and rapid high performance thin layer chromatographic method has been developed and validated for the determination of cefpodoxime proxetil in dosage form. The stationary phase used was precoated silica gel 60F254. The mobile phase used was a mixture of chloroform: methanol: toluene (4:2:4 v/v/v). The detection of spot was carried out at 289.0 nm. The method was validated in terms of linearity, accuracy, precision and specificity. The calibration curve was found to be linear between 100 to 700 ng/spot for cefpodoxime proxetil. The limit of detection and the limit of quantification for the cefpodoxime proxetil were found to be 30 ng/spot and 90 ng/spot, respectively. The proposed method can be successfully used to determine the drug content in marketed formulation. [ABSTRACT FROM AUTHOR]

A simple new spectrophotometric method has been developed for determination of rabeprazole in pharmaceutical bulk dosage form. The method was based on the formation of ion-pair complexes of the drug with four dyes, viz. bromo thymol blue, bromocresol green, bromophenol blue and bromocresol purple in acidic buffer solutions followed by their extraction in chloroform. The absorbance of the organic layer was measured at its respective wavelength of maximum absorbance against the corresponding reagent blank. The method has been statistically evaluated and was found to be precise and accurate. Phosphate buffer of pH 2 and bromocresol green dye gave maximum absorbance of rabeprazole at 454 nm. [ABSTRACT FROM AUTHOR]

Simple and reproducible HPTLC method was developed for the separation and quantitation of simvastatin, pravastatin sodium and rosuvastatin calcium, cholesterol lowering agents in pharmaceutical dosage forms. The stationary phase used was precoated silica gel 60F254. The mobile phase used was a mixture of chloroform:methanol:toluene (6:2:2, v/v/v). The method has been completely validated and proved to be rugged. Calibration curves were linear over the studied ranges with correlation coefficients grater than 0.999. All the drugs were extracted from the respective tablets using methanol. The percentage recoveries ranged from 100 to 101 for simvastatin, 98 to 101 for pravastatin sodium and 98 to 102 for rosuvastatin calcium. The LOD for simvastatin, pravastatin sodium and rosuvastatin calcium were found to be 15, 9 and 8 ng/spot, respectively and LOQ were 200 ng/spot for simvastatin and 100 ng/spot for pravastatin sodium and rosuvastatin calcium. The method can be useful in the quality control of bulk manufacturing and tablet dosage forms. [ABSTRACT FROM AUTHOR]

A simple, precise, accurate and rapid high performance thin layer chromatographic method has been developed and validated for the determination of cefuroxime axetil in dosage form. The stationary phase used was precoated silica gel 60F254. The mobile phase used was a mixture of chloroform:methanol:toluene (4:2:2 v/v). The detection of spot was carried out at 290 nm. The method was validated in terms of linearity, accuracy, precision and specificity. The calibration curve was found to be linear between 300 to 800 ng/spot for cefuroxime axetil. The limit of detection and the limit of quantification for the cefuroxime axetil were found to be 50 ng/spot and 100 ng/ spot. The proposed method can be successfully used to determine the drug content of marketed formulation. [ABSTRACT FROM AUTHOR]

Two simple, sensitive, rapid, accurate and economical methods were developed for the estimation of ciprofloxacin and ornidazole in two-component solid dosage form. First method is based on the simultaneous equation, and second method is based on Q-analysis (absorbance ratio method). Ciprofloxacin has absorbance maxima at 271.4 nm, and ornidazole has absorbance maxima at 320 nm in distilled water. The linearity was obtained in the concentration range of 2-10 µg/ml for ciprofloxacin and 2-20 µg/ml for ornidazole. In the first method, the concentrations of the drugs were determined by using simultaneous equations; and in the second method, the concentrations of the drugs were determined by using ratio of absorbances at isoabsorptive point and at the λmax of one of the drugs. The results of analysis have been validated statistically and by recovery studies. [ABSTRACT FROM AUTHOR]

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 60F254. 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. [ABSTRACT FROM AUTHOR]