ABSTRACT Clindamycin HCl is used in the treatment of acne. Development of an ethosomal delivery system to overcome the problem of penetration of clindamycin HCl into the skin layer. The aim of this study was to obtain good ethosomal characteristics of clindamycin HCl by optimization process. Optimization was carried out using a factorial design method of 22 through Design-Expert 12® with a pho…