Abstract The aim of present study is to formulate and evaluate the bilayered tablets containing Rosuvastatin as immediate release (IR) portion and Metformin Hydrochloride as sustained release (SR) portion in order to produce a single tablet containing two different classes of drugs as widely prescribed by doctors and to have better patient compliance. The sustained release layer of Metformin HCl was prepared by using different grades of swellable polymer HPMCK4M and HPMC E3 LV, Ethyl Cellulose by wet granulation method. The Immediate release tablets of Rosuvastatin by wet granulation method using various concentration of sodium starchglycolate as super disintegrant. The powders were evaluated for their flow properties and the finished tablets were evaluated for their physical parameters. The drug release study of Rosuvastatin and Metformin Hydrochloride were evaluated using
Type II (Basket) dissolution apparatus under sink condition. The release studies of Rosuvastatin were carried out for
30 minutes by using 900ml of pH 7.4 phosphate buffer was used as dissolution medium at a temperature of 37⁰C ±0.5⁰C. The paddle was stirred at a speed of 100 rpm by using UV- Visible spectrophotometer measured at 354 nm. And for Metformin hydrochloride the release studies were carried out for 10 hours in 900ml of 0.1N HCl was used as dissolution medium for first 2 hours followed by pH 6.8 phosphate buffer solution for next 8 hours maintained at a temperature of 37⁰C ±0.5⁰C. The paddle was stirred at a speed of 100 rpm by using UV-Visible spectrophotometer measured at 233 nm. The release rates of Rosuvastatin from all the formulations were more than 99.74% at the end of 30 minutes. In case of HPMC K4M and HPMC E3 LV, ETHYL CELLULOSE based tablets with the increasing of polymer content the release mechanism moved to super case. Total four trial batches of each drug have been manufactured to optimize and develop a robust and stable formulation, the stability studies of the products also comply with ICH guidelines.
Keywords Bilayer tablets, Rosuvastatin, Metformin Hydrochloride, HPMC, Sustained release, Immediate release.