Design and Evaluation of Bi-layer Drug Delivery System of Atorvastatin and GlipizideAuthor(s): V. Suriya Narayanan, A. Abdul Hasan Sathali and P. Ashok Kumar
The main focus of this study is to develop bi-layer tablets containing immediate release (I. R.) layer of atorvastatin and extended release (E. R.) layer of glipizide. atorvastatin I. R. tablets and glipizide E. R. tablets were prepared separately and were evaluated. From the in vitro dissolution studies, the I. R. formulation (A3) and the E. R. formulation (K1) were selected for further formulation into bi-layer tablets. The in vitro dissolution study of the bi-layer tablet showed that the percentage of atorvastatin released from I. R. layer was 76.9% within 45 min and the percentage of glipizide released from the E. R. layer was 31.64% in 8 hrs. All the formulations showed no change in physical appearance and in drug content after storage at 40 ± 2°C / 75 ± 5%RH for 3 months. DSC studies indicated no possibility of interaction between drugs and other formulation excipients.