Improving the solubility of nevirapine using A hydrotropy and mixed hydrotropy based solid dispersion approach.

BACKGROUND: Nevirapine, an antiviral drug, is a potent reverse transcriptase inhibitor (NNRTI). It is used in combination with nucleoside analogues for treatment of HIV type-1 (HIV-1) infection and AIDS. Nevirapine is a BCS class II drug which shows dissolution rate limited absorption. OBJECTIVES: The aim of the present research was to provide a fast dissolving solid dispersion of nevirapine. MATERIAL AND METHODS: The solubility of nevirapine was initially determined individually in four hydrotropic agents - namely urea, lactose, citric acid and mannitol - at a concentration of 10, 20, 30 and 40% w/v solutions using purified water as a solvent. The highest solubility was obtained in the 40% citric acid solution. Then different combinations of 2 and 3 hydrotropic agents in different ratios were used to determine solubility, so that the total concentration of hydrotropic agents was always 40%. RESULTS: The highest solubility was obtained in a solution of lactose and citric acid at the optimum ratio of 15:25. This optimized combination was utilized in preparing solid dispersions by a common solvent technique using distilled water as a solvent. The solid dispersions were evaluated for XRD, DSC and FTIR to show no drug-hydrotrope interaction. CONCLUSIONS: It was concluded that the concept of mixed hydrotropic solid dispersion is a safe, novel and cost-effective technique for enhancing the bioavailability of poorly water-soluble drugs by dissolving the drug in a nonionized form. The enhancement in solubility of nevirapine using hydrotropy is a clear indication of its potential to be used in the future for other poorly water-soluble drugs in which low bioavailability is a major concern

Formulation, characterization and in-vitro evaluation of fast dissolving tablets containing gliclazide hydrotropic solid dispersions

© 2017 Bentham Science Publishers. Background: Low aqueous solubility is a major problem faced with new drug molecules. The purpose of this research was to provide a fast dissolving oral dosage form of Gliclazide (GLZ) using the concept of mixed hydrotropy. The recent patents on Adenosine (US20140107059A1), Growth hormone releasing factor peptide (EP0984788A1) and Paclitaxel (WO2002030466A2) helped in selecting the hydrotropes. Methods: Solubility of GLZ was determined individually in sodium salicylate, nicotinamide, lactose, sodium acetate, urea, trisodium citrate and sodium benzoate. Highest solubility was obtained in 40% sodium benzoate solution. In order to decrease the individual hydrotrope amount, mixed hydrotropic agents were used. Results: Highest solubility was obtained in 25:15 ratio of sodium salicylate and sodium benzoate. This optimized combination was utilized in the preparation of solid dispersions which were evaluated for X-ray diffractometry, Differential Scanning Calorimetry (DSC) and Fourier-transform infrared to show no drug-hydrotropes interaction. This solid dispersion was compressed to form fast dissolving tablets. Dissolution studies of prepared tablets were done using USP Type II apparatus. Conclusion: The batch G3 tablets showed 86% cumulative drug release within 14min with in vitro dispersion time of 33sec. It was concluded that the enhancement in solubility of GLZ is a clear indication of the potential of mixed hydrotropy which is a novel, safe and cost-effective technique to be employed for other poorly water-soluble drugs having low bioavailability