Formulation and evaluation of press coated tablets of esomeprazole for colonic delivery

Abstract

The present study was aimed to formulate press‐coated tablets of esomperazole magnesium trihydrate for colon specific delivery. Press coated tablets were formulated with an aim to prevent the gastric degradation of drug so as to improve the bioavailability of drug.Various polymers such as pH‐dependent (Eudragit L100, Eudragit S100), enzyme‐dependent (Pectin),and time‐dependent (HPMC K4M) were selected for press coating the drug‐incorporated core tablets. Fourier Transform Infrared (FTIR) analysis was performed to check the compatibility of drug and polymers. Core and coating materials were evaluated for pre‐compression parameters like bulk density, tapped density, angle of repose, carrs index, and hausner’s ratio.Press coated tablets were evaluated for hardness, thickness, friability, tensile strength, drug content, and in vitro drug release. In vitro release studies were performed for 24 hours, first 2 hours in 0.1 N HCl, 3 hours in phosphate buffer (pH 6.8), and then for 19 hours in phosphate buffer (pH 7.4). In vitro drug release studies revealed that the tablets coated with pH‐dependent,enzyme‐dependent, and time‐dependent polymers showed no drug release in 0.1 N HCl, except for tablets coated with Pectin (25% and 50%, w/w). Kinetic modeling showed that the release exponent (n) value for all formulations was >0.89,indicating super case II transport to be the drug release mechanism. Press coated tablets for colonic delivery of esomeprazole magnesium trihydrate were successfully developed.