Development and Physicochemical Characterization of Hydroxypropylmethylcellulose Patches Containing Derris scandens extract

Abstract

Formulations of topical patches containing Derris scandens extracts (DSE) were developed and their physicochemical properties were investigated. The patches were prepared by solvent casting evaporation technique using various proportions of DSE concentrations (A), the polymer ratios of HPMC E4M and E15LV (B), and the amount of PEG 400 (C). Central composite design was adopted to determine the effect of the above formulation factors on the tensile strengths of the patches. It was found that tensile strengths were in the range of 151.88+46.58 g/cm2 to 902.89+101.05 g/cm2, with suitable hardness and brittleness. The mathematical equation was used to fit the independent variables with tensile strength of the patches. The optimization model showed the prediction of the tensile strength with A, B, and C levels of 0.6 g, 48:52 and 40%, respectively. The optimal composition resulted in suitable tensile strength of 571.28 ± 37.61 g/cm2 and showed a good correlation between predicted and observed values. The in vitro drug release from the DSE patches was performed in 10% w/v ethanol in phosphate buffer saline and 50% w/v ethanol. Maximum concentrations of drug released were obtained within 6 hours and 1 hour for 10% w/v ethanol in phosphate buffer saline and 50% w/v ethanol, respectively. The release rates were found to decrease with increasing polymer proportions of HPMC E4M and E15LV. The drug release kinetics of Higuchi models fit well to DSE release data of optimized patches. Hence, DSE patches have potential as an alternative dosage form to oral preparation and could be further developed for the study of in vitro skin permeation of DSE.