Exploring the Potentials of Corn Fiber Gum in Fabricating Mucoadhesive Floating Tablet of Poorly Gastro-retainable Drug.

AIM: To formulate and preliminary evaluated polysaccharide based mucoadhesive floating tablets of Cinnarizine. BACKGROUND: Gastro-retentive drug delivery systems has proved to be a successful approach to enhance the gastric residence with site specific targeting for achieving local or generalized effect. Various patents has also been filed globally employing gastro-retentive approach. OBJECTIVE: The study is designed to explore the mucoadhesive and low density characteristics of corn fibre gum (CFG) for preparation of gastro-retentive floating tablets of cinnarizine. METHODS: Floating tablets were prepared by direct compression technique using different concentrations of CFG (45, 50, 60% w/w). The formulated floating tablet batches were evaluated for their hardness, friability, drug content, floating duration/ lag time, swelling behavior, bioadhesive strength and in vitro drug release. RESULTS: Mucoadhesive strength was found to increase with an increment in the polysaccharide concentration. Swelling index was found to increase both with the increase in CFG concentration and with duration for which tablet remains in medium. The in vitro drug release studies indicated decrease in drug release (91% to 77%) with the increase in polymer concentration. The release data was further fitted to various kinetic models which revealed the drug release to be in accordance with Zero-order and Higuchi models, indicating polymer to exhibit the swellable matrix forming abilities. The value of n (between 0.458 and 0.997) from Korsemeyer Peppas model depicted the possibility of drug to follow more than one mechanism of release from the formulation i.e. diffusion and erosion. Stability studies revealed the preparations to retain their integrity and pharmaceutical characteristics at variable storage conditions. CONCLUSION: Thus from the research findings, CFG could be concluded to possess potential binder, release retardant and mucoadhesive characteristics which could be successfully employed for the formulation of gastro-retentive floating tablets.

Extraction and RP-HPLC determination of taxol in rat plasma, cell culture and quality control samples.

A rapid, sensitive, selective and validated reverse phase high-performance liquid chromatography (RP-HPLC) method for the estimation of paclitaxel in micro-sample of rat plasma and in culture of cancer cells was performed in this study. The mobile phase consisted of an optimized mixture of methanol:water: trifluroacetic acid (80: 20: 0.1, v/v/v). Column elution at a flow rate of 1 mL/minute with UV detection at 225 nm at room temperature was used. The RP-HPLC method was successfully applied for the determination of paclitaxel in plasma samples and in culture of cancer cells with nano-quantity of estimation. The validation studies were performed in accordance with the International Conference on Harmonization (ICH) guidelines. The intra- and inter-day precision showed that the coefficients of variation ranged from 1.07% to 4.27% at different levels of concentrations. To the best of our knowledge, this study also reported for the first time the optimization of different solvents for effective extraction of paclitaxel wherein tert.-butyl methyl ether (TBME): diethyl ether (DEE) in 50: 50 v/v composition was found most efficient with extraction efficiency ranging between 77.99% and 91.74% and between 76.14 and 93.66% in the plasma and cell culture, respectively. This proposed method was successfully applied to study the pharmacokinetics of paclitaxel and the influence of verapamil and all-trans retinoic acid (atRA) on paclitaxel pharmacokinetics in rat models. This proposed method might emerge as a valuable aid in the laboratory monitoring of paclitaxel in a variety of in vitro as well as in vivo scenarios.

In Vitro and In Vivo Study of Poly(ethylene glycol) Conjugated Ibuprofen to Extend the Duration of Action.

Ibuprofen-polyethylene glycol (PEG) conjugates (PEG-Ibu) were prepared and their potential as a prolonged release system was investigated. Two PEG-Ibu conjugates were synthesized from Ibuprofen and PEG with two different molecular weights by esterification in the presence of DCC and DMAP. The PEG-Ibu conjugates were characterized by FT-IR, (1)H NMR, Mass spectroscopy and DSC analysis. The solubility study in aqueous system showed an increase in solubility of conjugates. The dissolution / hydrolysis studies showed a specific acid-base catalysis pattern dependent on the pH of the medium. This indicated a good chemical stability in aqueous buffer solution of acidic medium and the extended release behavior was found in both prodrugs after 9 hour. The results demonstrate that, in the same condition, the rate of hydrolysis for PEG(4000)-Ibu is slower than other. The Writhing induced by acetic acid experiment and paw edema test after oral administration showed that both conjugates had extended analgesic and anti-inflammatory effects compared with Ibuprofen. These results suggest that PEG-Ibu could be a promising NSAID prodrug with an extended pharmacological effect owing to delayed-release of parent drug.

Simultaneous estimation of amlodipine besylate and nebivolol hydrochloride in tablet dosage forms by reverse phase-high-performance liquid chromatographic using ultraviolet detection.

BACKGROUND: The present study aimed to develop and validate the simultaneous estimation of amlodipine and nebivolol in tablet dosage forms. MATERIALS AND METHODS: An isocratic reversed phase high-performance liquid chromatographic (HPLC) method with ultraviolet detection at 268 nm has been developed for the determination of amlodipine besylate (ADB) and nebivolol hydrochloride in dosage formulation. RESULTS: Good chromatographic separation was achieved by using a stainless steel analytical column, the Lichrospher ODS RP-18 column (250 × 4 mm), particle size 5 µm. The system was operated at ambient temperature (25 ± 2°C) using a mobile phase consisting of acetonitrile (ACN) and a phosphate buffer (pH 3.0), mixed in a ratio of 40 : 60 at a flow rate of 0.8 ml/minute. The slope, intercept, and correlation coefficient were found to be 8818.2, - 18159, and 0.9993 for amlodipine and 9048.7, 108595, and 0.9998 for nebivolol, respectively. The proposed method was validated for its specificity, linearity, accuracy, and precision. CONCLUSION: The method was found to be suitable for the quality control of amlodipine besylate and nebivolol hydrochloride simultaneously in a bulk drug as well as in a formulation.

Antioxidant and hepatoprotective activity of ethanolic and aqueous extracts of Momordica dioica Roxb. leaves.

In present study, the hepatoprotective activity of ethanolic and aqueous extracts of Momordica dioica Roxb. leaves were evaluated against carbon tetrachloride (CCl4) induced hepatic damage in rats. The extracts at dose of 200mg/kg were administered orally once daily. The substantially elevated serum enzymatic levels of serum glutamate oxaloacetate transaminase (AST), serum glutamate pyruvate transaminase (ALT), serum alkaline phosphatase (SALP) and total bilirubin were restored towards normalization significantly by the extracts. Silymarin was used as standard reference and exhibited significant hepatoprotective activity against carbon tetrachloride induced haptotoxicity in rats. The biochemical observations were supplemented with histopathological examination of rat liver sections. The results of this study strongly indicate that Momordica dioica Roxb. leaves have potent hepatoprotective action against carbon tetrachloride induced hepatic damage in rats. Ethanolic extract was found more potent hepatoprotective. Meanwhile, in vivo antioxidant and free radical scavenging activities were also screened which were positive for both ethanolic and aqueous extracts. This study suggests that possible mechanism of this activity may be due to free radical-scavenging and antioxidant activities which may be due to the presence of flavonoids in the extracts.