Design and Formulation of Esomeprazole controlled porosity osmotic pump System Using micro and Nanosuspension Coating method and evaluation of drug release

Abstract

Introduction: Osmotic pump systems have many advantages over conventional pharmaceutical form. The zero-order release of active ingredients form drug formula and independence of drug release from external conditions such as the pH of the digestive system are prominent advantages of these formulations. Controlled porosity osmotic pump (CPOP) is considered one of the most attractive systems due to its ease of production (no need for special and complex devices) and greater ability to control the release pattern.Purpose: Development of D24-hour controlled porosity osmotic pump (CPOP) of esomeprazole with zero order release.Methodology: Osmotic pump’s drug reservoir was prepared by direct compression method and then coated by immersion method. Drug release was measured by USP II standard dissolution rate measuring device (paddle model). The formulation of the porous membrane in this study includes cellulose acetate as a semi-permeable membrane, castor oil as a hydrophobic plasticizer, and polyethylene glycol as a pore forming agent. In this study, four parameters, including D24h (total amount of release after 24 hours), tL (lag time) , MPDzero (mean proportional difference) , and RSQzero (squared correlation coefficient), to compare different formulations and select the one with most satisfactory results. Results: from the results obtained from the release profile of different samples, three formulations represented competent zero order results. Sodium carbonate, lactose, magnesium stearate, sorbitol, avicel, hydroxyl propyl methyl cellulose (HPMC), Cellulose acetate, castor oil, glycerin, and PEG400 were used in these formulations. In the end, the most benfitting one was selected to be represented as the optimized formulation.