DEVELOPMENT AND EVALUATION OF CONTROLLED RELEASE LOSARTAN POTASSIUM FORMULATION USING DIFFERENT POLYMERS

Esmat Zien El-Deen, Ahmed Donia and Rasha Zidan*

ABSTRACT

The present study was undertaken to develop and evaluate controlled release formulations of Losartan potassium by using different polymers in various drug to polymer ratios [1:1, 1:2 &1:3]. Polymers used were Eudragit RS100, Eudragit L100, Eudragit S100, Ethyl cellulose and Hydroxypropylmethylcellulose (HPMC). Fourier Transform Infrared spectroscopy (FT-IR) as well as Differential Scanning Calorimetry (DSC) studies revealed no chemical interaction between the drug and polymer used. The micromeritic properties of the prepared formulations proved that by increasing the ratio of the polymer in the blend, it was followed by decreasing the angle of repose (from 40.20 0 of the plain drug to 29 0), Carr,s index (from 31.40% of the plain drug to 9% ), Hausner ratio (from 1.46 of the plain drug to 1.02). Drug release from the prepared formulations was followed at three pH values [1.0, 6.8 &7.4] representing the main segments of G I T. It was revealed that by increasing the concentration of the polymer in the blend a retarding effect of the drug release was observed in the orded 1:3> 1:2>1:1. Mixing the plain drug with solid dispersion system of Eudragit L100 (that offers drug release at pH6.8) and solid dispersion system of Eudragit S100 (that offers drug release at pH7.4) in a physical mixture offers both immediate and controlled release thus increase the patient compliance.

Keywords: Losartan potassium, solid dispersions, controlled release.