メトキシケイヒ酸2-エチルヘキシルの皮膚移行に与える
2-Methacryloyloxyethylphosphorylcholine Butylmethacrylate 共重合体の影響
藤井まき子*，和久井 京*，花田真隆*，大谷寿子*，石川亜紀子*，近藤昌夫*，渡辺善照*
Effect of 2-Methacryloyloxyethylphosphorylcholine Butylmethacrylate Copolymer on the Skin Penetration of 2-Ethylhexyl Methoxycinnamate
Makiko FUJII*, Miyako WAKUI*, Masataka HANADA*, Hisako OTANI*, Akiko ISHIKAWA*, Masuo KONDOH*, Yoshiteru WATANABE*
Abstract:
We studied a formulation which inhibits skin penetration of 2-ethylhexyl methoxycinnamate (MCO). Emulsions(o/w) containing 50MCO and 50 soybean oil (SO) were prepared using 2-methacryloyloxyethyl phosphorylcholine butylmethacrylate copolymer (PMB), egg phosphatidylcholine (PC) or polysorbate 80 (TO) as an emulsifier. The use of a high-pressure emulsifier resulted in a mean oil droplet size of 200500 nm, which did not change over at least one month. Skin penetration of MCO was determined by testing with Yucatan micropig skin in vitro. When emulsions were applied under infinite conditions (2 ml/cm2, closed), there was no di#erence among the formulations.
Under finite conditions (2 ml/cm2, open), about 900 of the MCO was retained in the stratum corneum when the emulsion made with 40PMB was used; this proportion was significantly higher than those obtained with other emulsions. The emulsions made with PC and TO changed phase from o/w to w/o in drying process; however, the emulsion made with PMB showed no phase change and was dried with maintenance of the oil phase (MCO1SO) in PMB. An in vivo study with rabbits also showed high retention in the stratum corneum when a 40PMB emulsion was used. Thus, polymer surfactant PMB is useful for achieving retention of MCO on the surface of the skin and preventing penetration into the viable epidermis.
Key Words:
2-ethylhexyl methoxycinnamate, skin penetration, 2-methacryloyloxyethylphosphorylcholine butylmethacrylate copolymer, emulsion.
* 昭和薬科大学薬剤学研究室
Dept. Pharmaceutics and Biopharmaceutics, Showa Pharmaceutical University