A RESEARCH OF FORMULATION AND EVALUATION OF ESOMEPRAZOLE ENTERIC COATED TABLETS USING CELLULOSE ACETATE PTHALATE

Oral ingestion is the predominant and most preferable route for drug delivery mainly due to their convenience of administration, patient compliance and their suitability for delivery of drugs for systemic effects. Following oral administration most drugs have to be absorbed into the blood to produce therapeutic action. However certain drugs have a “region-specific absorption” or absorption window. Enteric-coated tablets with a low core pH will have longer in vivo disintegration time, due to the suppression of ionization of enteric coating polymers in the acidic environment. As a result, tablets with a high proportion of an acidic therapeutic agent or acidic excipients would probably exhibit retardation in dissolution if directly enteric coated. Considering the dissolution in general and stability in particular, the pH of the core tablet was basified using sodium bicarbonate (50 mg). Three different core tablets (C1- C3) of Esomeprazole (40 mg) were prepared with varying concentration of super disintegrants crospovidone (CP), Sodium starch Glycolate (SSG), croscarmellose sodium (CCS), Dissolution analysis was employed to assess the effect of the enteric coat composition and coverage levels on the release of the formulations. In vitro drug release was carried out for formulations with CAP 2%, 3%, 4% (C3F1-C3F3) in 0.1 N HCl for 2 h followed by phosphate buffer pH 6.8 for 60mins. Compares the dissolution profile of enteric coated Esomeprazole tablets prepared using CAP (2%, 3%, 4%) in phosphate buffer pH 6.8. It is evident that (C3F3) demonstrated excellent physical resistance to the acid medium with the acid uptake value 1.22±0.06 in 2 hrs. However, formulations which were enteric coated 2% and 3% CAP fail the disintegration test carried out at pH 1.2. The study indicates that 4% CAP suitable for enteric coating. It provides greater protection to the core under acidic condition while at the same time show the fastest drug release under intestinal pH. The optimized formulation was C3F3.