Formulation and Evaluation of Rabeprazole Microspheres

Microspheres can be tailored to provide targeted and/or sustained release in different parts of the body, including those of eye, nasal cavity, urinary, colon and gastrointestinal tract, thus offering the possibilities of localized as well as systemic controlled release of drugs. Prolonged release of drugs and a reduction in frequency of drug administration can highly improve the patient compliance. Recent advances in targeted drug delivery and sustained release of drug uses this mechanism even for the delivery of protein and peptide drugs, antigens for vaccination and plasmid DNA for gene therapy. In the present work we have developed the formulation of microspheres for an anti-ulcer drug Rabeprazole which has very less plasma half life 0.85 hrs, hence it is necessary to develop the formulation which will provide the sustained release of the drug thereby reducing the dose of the drug. We developed and characterized the microsphere formulation which improved the efficacy of the drug and hence reduce the side effects. Characterization also showed that there is no drug excipients interaction. The present study was planned to prepare microspheres for sustained release of using Rabeprazole & various cellulose polymers such as Ethyl cellulose, Cellulose acetate phthalate, cellulose acetate by employing solvent evaporation technique. Microspheres were Characterized for the particle size distribution, wall thickness by Scanning electron microscopy (SEM), angle of repose, drug content , bulk density, entrapment efficiency and in vitro dissolution studies. Drug excipients compatibility was determined by FTIR and DTA. Accelerated stability studies were also carried out following ICH Guidelines. SEM shows that microspheres were found spherical in shape and free flowing. The entrapment efficiency and wall thickness was found in between 68.85% & 42.88%, 120.28μ & 72.32μ respectively. The drug release was extended maximum up to 12 hrs with ethyl cellulose. FTIR and DSC results showed Rabeprazole was compatible with excipients. The curve fitting data shows that the drug release followed first order kinetics, Higuchi’s and Peppa’s plots stated non-fickian diffusion controlled.