Sandwiched osmotic pump tablet for controlled release of water-insoluble drug
Liu, L-xiao.; Khang, G.; Rhee, J.Moon.; Lee, H.Bang.
Yao Xue Xue Bao 38(8): 620-623
2003
ISSN/ISBN: 0513-4870 PMID: 14628456 Document Number: 559226
Aim: To study sandwiched osmotic pump tablet for delivering water-insoluble drug for 24 hours. Methods: Sandwiched osmotic pump tablet was prepared using nifedipine as the model drug. The effects of various formulation variables and orifice size on drug release were studied. The mechanical properties of cellulose acetate membrane were also investigated. Results: Polyethylene oxide of drug layer and potassium chloride of push layer showed marked positive effects on drug release. In the range of 0.50 mm to 1.40 mm, orifice size hardly affects drug release. Cellulose acetate membrane is strong enough to assure the integrity of osmotic pump tablet and could sustain an internal pressure ranging from 0.34 MPa to 2.85 MPa. Conclusion: Sandwiched osmotic pump tablet can deliver water-insoluble drug constantly for 24 hours. Release media and agitation rate scarcely affect drug release. Compared with the commercialized push-pull osmotic pump tablet, sandwiched osmotic pump tablet is easy in preparation with exempting identification of drug layer before drilling.