Further Evaluation of a New Penetration Enhancer,HPE-101

Abstract— The penetration enhancer, 1-[2-(decylthio)ethyl]azacyclopentan-2-one (HPE-101), significantly enhanced the excretion of topically applied [¹⁴C]indomethacin when dissolved in dipropylene glycol, triethylene glycol, diethylene glycol, 1,3-butylene glycol, trimethylene glycol, glycerin, water, silicone or triethanolamine, but not when dissolved in ethanol, isopropyl alcohol, oleyl alcohol, olive oil, peppermint oil, isopropyl myristate or hexylene glycol. HPE-101 significantly enhanced the excretion of [¹⁴C]indomethacin, [¹⁴C]nicotinic acid, [¹⁴C]5-fluorouracil, [³H]oestradiol and [³H]triamcinolone acetonide, but not that of [³H]testosterone. HPE-101 also significantly enhanced the excretion of [¹⁴C]indomethacin applied to intact skin of rabbit, guinea-pig and rat, and to tape-stripped skin of guinea-pig, but did not enhance the excretion of [¹⁴C]indomethacin applied to tape-stripped skin of rat or rabbit.