Abstract

A sustained release system for lansoprazole designed to increase its residence time in the stomach without contact with the mucosa was achieved through the preparation of floating micropellets by emulsion solvent diffusion technique. Floating micropellets of 1:1, 1:2 and 1:3 drug to carrier ratios were prepared using hydroxypropylmethylcellulose, methylcellulose and chitosan as a carrier. The yield of the micropellets was up to 82%. All floating micro pellet formulations showed good flow properties expect formulation contain hydroxypropylmethylcellulose as coating material and packability. Drug loaded micropellets were found to float on simulated gastric fluid and simulsted intestinal fluid for more than 12 h. The drug release studies were carried out in simulated gastric and intestinal fluid without enzymes at 37° for a period of 12 h. The Drug to chitosan ratio 1:1 showed good incorporation efficiency and high percentage in vitro release of lansoprazolc from micropeliets. The morphology and particle size analysis were analyzed by scanning electron microscopy and optical microscopy. The range of particle size is in between 327 to 431 pm. This method is simple, giving better yield and reproducible. The prepared lansoprazole floating micropellets can be used for sustained release in gastric media for more than 12 h, there by improving the oral bioavailability of lansoprazole by increasing gastric residence time because this helps to retained in stomach for a longer period.