Abstract: Objective To study the distribution pattern of liposome podophyllotoxin(LP)in rat skin.Methods The rats were divided into two groups:0.5% liposome podophyllotoxin suspension was applied to LP group,0.5% podophyllotoxin tincture was applied to control group.The skin specimens were obtained 1、2、4、6、12 and 24h after drug application,the amount of fluorescent stain was observed under confocal laser scanning microscope and converted to the values of area under the curve(AUC).Results The epidermal AUC of fluorescent amount in LP group was 1.5-fold than that in control group,dermal AUC was 2.3-fold higher.The unit area fluorescent amount in both epidermis and dermis was highest 2 hours after topical medication in control group(1585.52/μm² and 2005.66μm²),and quickly reduced after 4 hours.But the epidermal and dermal unit area fluorescent amount in LP group was rather low in 4 hours after topical medication,and gradually increased after6hours,and peaked after 12 hours(750.28/μm² and 1073.08/μm²).Conclusion Liposome preparation of podophyllotoxin can be slowly released and lasts longer in the skin.

Key words: Liposomes, Podophyllotoxin, Administration,cutaneous