Oleyl pyroglutamate for use as transdermal enhancer and its enhancing mechanism

To test the enhancing activity and the mechanism of oleyl pyroglutamate used as transdermal enhancer. The penetration-enhancing effects of oleyl pyroglutamate, oleyl alcohol and oleic acid on the three drugs (caffeine, tinidazole and cortisone) were observed; the transdermal enhancing mechanism of oleyl pyroglutamate was studied with the attenuated total reflectance Fourier-transfer infrared spectroscopy(ATR-FTIR) of the human stratum corneum in vivo. The penetration-enhancing ratio of the three drugs was 7.9 fold, 41.8 fold and 2.8 fold, respectively. The absorptions at 2,800-2,950 cm-1 and 1,642-1,646 cm-1 (amide-I) in the ATR-FTIR spectrum of the stratum were found to be shifted differently following removal of the stratum corneum which was treated with oleyl pyroglutamate. Oleyl pyroglutamate showed better penetration-enhancing effect on the penetration of drugs. Its transdermal enhancing mechanism may be that oleyl pyroglutamate induced not only disordering of the stratum corneum lipid, but also change o