Design Expert based Optimization and Permeation Study of Novel Topically Applied Anti-acne gel

In present study, Propylene glycol (PG) and Polyethylene glycol (PEG) were used as permeation enhancers to increase percutaneous absorption and release of CCT gel through silicone membrane. Gel formulations containing Clarithromycin (Macrolide antibiotic) and Cetirizine HCl (a non-sedative, anti-histaminic H-1 receptor) were formulated and optimized by using Response Surface Methodology (RSM) containing different ratios of PG and PEG. PG(X1) and PEG(X2) were taken as two independent variables whereas cumulative amount of Clarithromycin was used to calculate dependent (response) variables (Y1…Y7). From all formulated gels, Clarithromycin was released and permeated through silicon membrane using Franz diffusion cell at 37±1ºC. Fick's laws of diffusion were used to calculate permeation kinetic parameters like lag time (tlag), diffusion co-efficient (D), K, permeation co-efficient (Kp), Flux (J), enhancement ratios (ER) and input rate (IR). The physical properties of all gel formulations like clarity, pH, viscosity, solubility, partition co-efficient (Ko/w), homogeneity, spreadability and Ex-vivo Panel test, Draize's irritation test were performed. Analysis of variance (ANOVA) was conducted to evaluate the results which showed that the independent variables have remarkable effects (p < 0.05) on dependent variables. Multiple linear regression analysis was used to compare the results among control and different formulations of CCT gels. Contour plots were also constructed to show the response between dependent and independent variables. Two gels G4 and G5 were optimized. In optimized gels maximum cumulative amounts permeated through silicon membrane were high as compared to Gc. It was found that permeation was increased with the increase in concentration of both permeation enhancers in combination i.e. PG and PEG. Thus it was concluded that PG and PEG can be successfully used in combination as permeation enhancers for transdermal delivery of CCT gel.