Abstract

FORMULATION AND EVALUATION OF EFAVIRENZ IMMEDIATE RELEASE TABLETS BY USING MIXED HYDROTROPIC SOLUBILIZATION TECHNIQUE

S. Saibabu*, Jyothirmayi Pasam, K. Ratnaraju, M. Prathap, Y. Ashok Kumar

ABSTRACT

Low aqueous solubility is a major problem faced during formulation development of new drug molecules. Efavirenz (EFV) is an anti retroviral agent and is a good example of the problems associated with low aqueous solubility. Efavirenz is practically insoluble in water. Hence, purpose of this research was to enhance the solubility of EFV by using the concept of mixed hydrotropy. Initially, solubility of EFV was determined individually in sodium acetate, sodium citrate, urea and sodium benzoate at concentration of 10% w/v solutions using purified water as a solvent. Highest solubility was obtained in 10% sodium benzoate solution. In order to decrease the individual Hydrotrope concentration mixed hydrotropic agents were used. Highest solubility was obtained in 1:6:1 ratio of Urea + Sodium benzoate + Sodium acetate. This optimized combination was utilized in the preparation of solid dispersions by using distilled water as a solvent. Fourier-transform infrared to show no drug-hydro tropes interaction has occurred. Formulation of Immediate release tablets of Efavirenz using mixed hydro trophy technique with different concentrations of super disintegrants such as Crosspovidone, Croscarmellose sodium and sodium starch Glycolate were prepared by using direct compression method. Dissolution studies of prepared tablets were done using USP Type II apparatus. The batch CF3 tablets show 99.0% cumulative drug release within 40 min. It was concluded that the concept of mixed hydrotropic solid dispersion is novel, safe and cost-effective technique for enhancing the bioavailability of poorly water-soluble drugs. The miraculous enhancement in solubility and bioavailability of Efavirenz was clear indication of the potent mixed hydrotropy to be used in future for other poorly water-soluble drugs in which low bioavailability is a major concern.

Keywords: Efavirenz, Mixed hydrotropy, Solid dispersions.