FORMULATION AND PHYSICAL EVALUATION OF TOPICAL PATCH CONTAINING DERRIS SCANDENS

Abstract

Formulation of topical patch containing Derris scandens extracts (DSE) for topical and transdermal drug delivery systems were developed and their physical properties including drug release were investigated. The topical patches of DSE were prepared by solvent casting evaporation technique using various proportions of DSE concentration (A), the polymer proportion 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, demonstrating the patches with suitable hardness and brittleness. The mathematical equation was used to relate independent variables with tensile strength. The optimization model predicted the desired tensile strength with A, B, and C levels of 0.6 g, 48:52 and 40 %, respectively.  This optimum composition resulted in suitable tensile strength of 571.28 ± 37.61 g/cm2 and showed a good correlation between predicted and observed value. The in vitro drug release from the DSE patches were studied in 10%w/v ethanol in phosphate buffer saline and 50% w/v ethanol. Maximum concentrations of drug released obtained within 12 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 the increase in polymer proportion of HPMC E4M and E15LV. The drug releasee kinetics of Higuchi models fit well to DSE release data of optimized patches. Hence DSE patches have a potential as an alternative dosage form to oral preparation and could be further developed for the study of in vitro skin permeation of DSE.