Abstract
Different batches of slow release mebeverine-HCl beads were prepared by pan coating technique using different release retarding polymers viz Eudragit RL100, Eudragit RS100 and Ethyl cellulose. The thickness of the coats was controlled by changing the amounts of the added polymers. Pre- and overcoating of the beads with bees wax was also carried out. Mixtures of pre-waxed Eudragit RS100 coated and uncoated beads in different ratios were prepared to control both drug content and release.
Dissolution profiles of mebeverine HCl from the prepared beads were investigated using USP XX rotating basket method. Prolonged release of mebeverine-HCl was obtained from different batches of the coated beads with the advantage of no initial dumping of the water soluble drug. The release of mebeverine-HCl from the beads coated with acrylic resins and ethyl cellulose as well as waxed acrylic resins coated beads was diffusion controlled according to Higuchi model. Beads coated with ethyl cellulose showed a different release pattern when pre-or overcoated with wax. By altering the ratios of prewaxed Eudragit Rs100 coated and uncoated beads in formulated mixtures, it was possible to control both mebeverine-HCl content and release rate.