In vitro study on capsule formulations of omeprazole containing enteric coated granules

Omeprazole is a unique and effective agent for suppression of gastric acid secretion. It promises to be especially useful in Zollinger-Ellison Syndrome (1) and in other patients who have failed to respond to H2 antagonist therapy. The dose requirement for zollinger-ellison syndrome (ZES) disease is upto 180 mg per day. The drug omeprazole shows biological half life of 2-3 hours. (2) Considering its proven therapeutic efficacy for ZES disease, this study is attempted to formulate sustained release capsule containing enteric coated granules. For formulating sustained release drug delivery system immediate release dose (IR) is calculated as 10 mg of drug and sustained release dose (SR) is taken as 50 mg. (3) The polymers used for retarding the release are Ethyl Cellulose (EC) and Hydroxy Propyl Methyl Cellulose (HPMC). Solvent evaporation technique is followed to prepare sustained release granules. Granules are finally coated with enteric coating of Suteric (Polyvinly acetate phthalate, PVAP). Thus the eight capsule formulations are prepared and formulation found very close to theoretical sustained release (TSR) according to in vitro study (4) is subjected to stability studies. Results show that product should be stored at room temperature or below ambient temperature.