Iqbal Z, Watson D G, Midgley J M, Dennison P R, McGhee C N
Department of Pharmaceutical Sciences, University of Strathclyde, Glasgow, UK.
J Pharm Biomed Anal. 1993 Nov-Dec;11(11-12):1115-20. doi: 10.1016/0731-7085(93)80091-e.
Isolated bovine cornea was found to reduce the 20 ketone group in fluorometholone (FML) to produce a mixture of 20 alpha- and 20 beta-dihydrofluorometholone (DHFML). Incubation of FML with bovine cornea at pH 7.4 in phosphate buffer produced an increase in the amount of reduction products up to 8 h; after this time the rate of reduction decreased. The reduced products were quantified by GC-MS against [2H3] 20 alpha-DHFML. Variable amounts of 20 beta-DHFML were detected in six samples of human aqueous humour following topical application of 50 micrograms of FML to the eye. The rapid metabolism of the side chain of FML may account for the unexpected low concentrations of FML which are found in human aqueous humour following its application to the surface of the eye.
研究发现,分离出的牛角膜可使氟米龙(FML)中的20 - 酮基还原,生成20α - 和20β - 二氢氟米龙(DHFML)的混合物。在pH 7.4的磷酸盐缓冲液中,将FML与牛角膜一起孵育,还原产物的量在8小时内不断增加;此后还原速率下降。通过气相色谱 - 质谱联用仪(GC - MS),以[2H3] 20α - DHFML为对照对还原产物进行定量分析。对眼部局部应用50微克FML后,在六个样本的人房水中检测到了不同量的20β - DHFML。FML侧链的快速代谢可能是其应用于眼表后,人房水中FML浓度意外偏低的原因。