Abstract
BACKGROUND: Combination of curcumin with anti-inflammatory drug like caffeine shows augmented antipsoriatic action compared to curcumin alone and reduce the time taken for treatment of Psoriasis. OBJECTIVE: The objective of the present study was to develop nanosponge (NS) based topical gel of curcumin (CUR) and caffeine (CFN) combination that acts as a potential system for the treatment of psoriasis. METHODS: NS composed of dimethyl carbonate (DMC) as crosslinker and beta-cyclodextrin (β-CD) as polymer were prepared by hot melt method and incorporated in topical gels. Factorial design (3(2)) was constructed in a fully randomized manner to study all nine possible experimental runs. The gels were prepared by varying the content of carbopol-934 (gelling agent) (X1) and guar gum (polymer) (X2). The effect of these two independent variables on viscosity (Y1) and in vitro percent drug release (Y2) of prepared gels was evaluated. Other evaluation studies for NS and nanogels were conducted. In vivo animal studies were carried out for optimized formulation using mouse model of imiquimod-induced psoriasis. RESULTS: The physical and chemical characteristics exhibited by the prepared NS and gels (F1-F9) were found to be optimal. The optimization resulted in achieving formulation N10 with 69.72% in vitro drug release and 12,329.78cp viscosity. Histopathology studies revealed that prepared nanogel has promising anti-psoriatic activity. The results concluded that CUR and CFN combination has reduced the time required for showing anti-psoriatic activity to 10 days when compared to CUR alone that took around 20 days. Moreover, the nanogel has depicted sustained drug release till 12 h. CONCLUSIONS: From the experimental findings it has been concluded that CUR and CFN combination significantly augmented the anti-psoriatic efficacy with respect to individual components and also reduced the time required for onset of effect. Thus, the proposed nanogel would be an imperative drug delivery system for more effective anti-psoriatic therapy. Graphical abstract.