Development and optimization of Clinacanthus nutans liquid spray using a two-level full factorial design.

Abstract

This study aimed to develop and optimize a topical Clinacanthus nutans liquid spray that dries quickly after spraying and has low stickiness. An experimental design was adopted to evaluate the effects of the amounts of polyvinylpyrrolidone (X1) and glycerol (X₂) and the ratio of acetone:ethanol (X₃) on the stickiness (Y1 ), solution viscosity (Y₂), evaporation rate (Y₃), and spray coverage radius (Y₄) of the solution. Results revealed that all independent factors had a substantial effect on Y1 -Y₃. In this model, the synergistic effect was uncommon. The optimized formulation consisted of X1 of 0.1%, X₂ of 1.0%, and X₃ of 59:41. The response values of Y1, Y₂, Y₃, and Y₄ were 92.24 mN, 4.63 cP, 0.0959%, and 9.40 cm, respectively. The actual results were close to those predicted by the experimental design model. Therefore, the optimized topical spray formulation can be used in actual practice.