Formulation development of Empagliflozin and Metformin hydrochloride extended release tablets: Optimization of formulation using statistical experimental design

The objective of the present study was to develop empagliflozin and metformin hydrochloride extended release tablets, consisting of immediate release empagliflozin and extended release metformin hydrochloride in a single tablet. Impact of various formulation variables and critical process parameters on drug release of immediate release part was studied. Direct blending process was employed to formulate immediate release part empagliflozin and compressed along with extended release part metformin hydrochloride into bilayer tablets. Analysis of variance was used to assess impact of various formulation variables on immediate release part drug release. A 32 (two factor, three level) factorial design was employed to study the effect of independent variables (binder concentration [hydroxy propyl cellulose] and disintegrant [croscarmellose sodium] concentration) on dependent variable (drug release at 30 min). Optimization was done by fitting experimental data to the software program (design expert). The design space for formulation variables and its influence on drug release was developed. Fabricated tablets were characterized for various physicochemical parameters. The optimized formulation showed desired drug release of empagliflozin from immediate release part at 30 min as 84.0% ± 1.03. Empagliflozin and metformin hydrochloride extended release tablets were successfully developed by employing direct blending approach for immediate release part formulae optimization and formulation optimization of immediate release part was facilitated by experimental design.