Statistical optimization of tretinoin-loaded penetration-enhancer vesicles (PEV) for topical delivery.

Background: The aim of this study was to develop and optimize deformable liposome for topical delivery of tretinoin.

Methods: Liposomal formulations were designed based on the full factorial design and prepared by fusion method. The influence of different ratio of soy phosphatidylcholine and transcutol (independent variables) on incorporation efficiency and drug release in 15 min and 24 h (responses) from liposomal formulations was evaluated.