Penetration enhancement of lidocaine hydrochlorid by a novel chitosan coated elastic liposome for transdermal drug delivery.

An effective transdermal delivery system for local anaesthetic was developed with lidocaine hydrochloride (LID) as model drug. Chitosan coated elastic liposome (CCEL) were proposed and its in vitro/in vivo skin permeation properties were evaluated. Elastic liposome composed of soya lecithin with sodium deoxycholate (SDC) as edge activator, was prepared by rotary evaporation-sonication method. Chitosan (CH) (0.1-0.5%, w/v) coated elastic liposome by electrostatic attraction of negative elastic liposome and positive CH. CH coating changed the elastic liposome surface charge and increased the vesicle size. The drug encapsulation efficiency (EE) decreased with the increase of CH content. CH coated elastic liposome demonstrated an improved physicochemical stability at 4 degrees C in a 3 months storage period. After coated, CCEL displayed a prolonged drug release profile in vitro release study. The in vitro/in vivo studies showed that CCEL were able to give a statistically significant improvement of skin permeation of LID and significantly reduced pain in comparison with elastic liposome and CH solution.