Abstract: The positive electret was prepared by the constant voltage corona charging method. After the application of the electret on rat skin for 2 hours, the skin was analyzed by differential scanning calorimetry (DSC). The results indicate that (1) there are three peaks at 65 ℃, 87 ℃ and 122 ℃ in the DSC spectra for control rat skin; (2) with the increase of electret surface potential, the peak temperature and peak area decrease as compared with control rat skin. Therefore, the biological effect of positive electret changes the space structure of lamellar lipid and protein, and increases the fluidity of lipid. Positive electret can enhance the drug transdermal delivery.

Key words: electret; polypropylene; differential scanning calorimetry spectra; rat; skin