A site-specific controlled-release system for metformin |
| |
Authors: | Di Colo Giacomo Zambito Ylenia Baggiani Andrea Carelli Vera Serafini Maria Francesca |
| |
Affiliation: | Department of Bioorganic Chemistry and Biopharmaceutics, University of Pisa, Via Bonanno 33, 56126 Pisa, Italy. giadic@farm.unipi.it |
| |
Abstract: | Oral absorption of the antihyperglycaemic agent metformin hydrochloride (MF-HCl) is confined to the upper part of the intestine, therefore rational controlled-release formulations of this drug should ensure a complete release during transit from stomach to jejunum. The aim of this study was the preparation of a system able to sustain release of high MF-HCl doses in compliance with the above requirement. Matrices (6 mm diameter; 50 mg weight) comprising varying drug-Precirol ATO 5 ratios were prepared by compression. The matrix containing 70% drug was coated on one face with Eudragit L100-55. Drug release to simulated gastric (SGF), jejunal (SJF) and ileal (SIF) fluids in sequence was studied using a modified USP rotating basket method. Release depended on drug load whereas it was independent of dissolution medium pH and hydrodynamics. Release kinetics were of radical t type and were determined by drug diffusion in aqueous pores created in the matrix by drug dissolution. An equation correlating rate-determining factors was developed, whereby the release pattern could be optimized. The half-coated matrix started release in SGF and completed it in SJF. The half-coated matrix, synchronizing drug release and matrix transit across the small intestine, may improve drug bioavailability and reduce side effects. |
| |
Keywords: | |
本文献已被 PubMed 等数据库收录! |
|