Development and Evaluation of Dual Release Tablet of Metformin and Pioglitazone for the Treatment of Diabetes Mellitus

The objective of present work is to develop and characterize dual release tablet formulation containing Metformin in extended release matrix form and Pioglitazone in immediate release form for the treatment of Diabetes mellitus. Different formulations containing Metformin HCl were manufactured using 32 factorial designs. Influences of hydrophobic carrier, hydrophilic polymer on drug release were studied. Immediate release layer of Pioglitazone was optimized using different disintegrants. All formulations were evaluated for percentage drug release and analyzed according to various release kinetic models. Optimization results indicated that release rate of Metformin is directly proportional to the levels of stearic acid (SA) and poly-ethylene-oxide (PEO). Kinetic analysis showed that formulation M6 was good releasing with f2 value of 81.08 and follows Higuchi and Peppas model with correlation coefficient value 0.9780 and 0.9910 respectively. Similarly, optimization study indicated that release of Pioglitazone is dependent on the level and type of disintegrant, formulation P5 shown highest f2 value of 84.08. Results confirmed that dual-release inlay-tablet formulation containing extended release of Metformin HCl and immediate release of Pioglitazone HCl could be developed for the treatment of Diabetes mellitus.