Formulation Development and Evaluation of Osmotic Controlled Drug Delivery System

A method for the preparation of controlled porosity osmotic pump tablet was obtained by modulating atenolol solubility with acid. Tartaric acid was used as solubility promoter, sodium chloride as osmotic agent. Ethyl cellulose was employed as semipermeable membrane containing polyethylene glycol 400 as pore forming agent. The effect of various variables on the release rate was studied and the optimized batch is selected. The optimal osmotic pump tablet was found to be able to deliver atenolol at the rate of approximate zero-order up to 24 h. The approach of solubilitymodulated by acid-alkali reaction might be used for the preparation of osmotic pump tablet of other poorly watersoluble drugs with alkaline or acid groups.