Formulation and In vitro Evaluation of Carvedilol Transdermal Delivery System

Purpose: To develop and optimize carvedilol transdermal delivery system. Methods: Solvent casting method was used to prepare patches using polymethyl methacrylate (PMMA) and Eudragit E100 (EE100) polymers, dimethylsulfoxide (DMSO) penetration enhancer, dibutylphthalate (DBP) plasticizer and Tween 80 surfactant. A 2^3 factorial design was used based on three variables (PMMA, EE100, DMSO). at two levels Second order polynomial equations indicating interplay of ingredients were obtained by factorial design using SigmaTech software for 1, 4, 8 and 20 h release data. so the design was extended to central composite design (CCD). The target formulation was obtained from contour plots and evaluated for various physicochemical parameters. including in-vitro dissolution studies. Results: Curvature effect was observed in F1 to F8 formulations, highlighting the interplay of ingredients. The interaction term (X2X3)exhibited highest Sum of Squares SS ratio at 1, 4, and 8 h data with positive coefficients indicating interaction; and so extended to CCD. From contour plots target formulation, F19, was identified and evaluated. The release data, were subjected to kinetic analysis, which followed Higuchi (diffusion) model (R^2 = 0.9886). Conclusion: F19 yielded release profile nearer to the theoretical predictions with R^2 of 0.9888 and followed Higuchi kinetics. Thus, a diffusion-mediated carvedilol matrix patch was successfully developed.