Schep L J, Jones D S, Shepherd M G
School of Pharmacy, University of Otago, Dunedin, New Zealand.
Pharm Res. 1995 May;12(5):649-52. doi: 10.1023/a:1016291021552.
The absorption of three quaternary ammonium compounds (QAC), cetylpyridinium chloride, cetrimide and benzalkonium chloride, onto the surface of blastospores of Candida albicans (MEN strain) was examined at room temperature. Equilibrium uptake occurred in less than 30 seconds for cetylpyridinium chloride and cetrimide whereas 5 min contact time was required for benzalkonium chloride. The adsorption of all three agents may be mathematically described as Langmuirian and hence a concentration-dependent formation of drug-monolayer on the surface of the blastospore occurred. From this the number of molecules adsorbed onto the surface of a single blastospore was calculated to be 1.33 x 10(12), 3.17 x 10(12) and 2.32 x 10(12) for cetylpyridinium chloride, cetrimide and benzalkonium chloride, respectively. These dissimilarities are most likely due to differences in the orientations of both the cationic nitrogen atom and the accompanying lipophilic portions of each QAC at the blastospore surface. Relating these observations to the known antiadherence effects of cetylpyridinium chloride and cetrimide, it can be concluded that monolayer coverage of the blastospore surface with QAC does not account for the observed reduced adherence. This suggests that the anti-adherence effects are due to either direct interaction with, or steric blockade of, adhesions on the blastospore surface.
在室温下，研究了三种季铵化合物（QAC），即十六烷基氯化吡啶、西曲溴铵和苯扎氯铵，在白色念珠菌（MEN菌株）芽生孢子表面的吸收情况。十六烷基氯化吡啶和西曲溴铵在不到30秒内达到平衡摄取，而苯扎氯铵则需要5分钟的接触时间。所有这三种药剂的吸附在数学上都可以描述为符合朗缪尔吸附等温线，因此在芽生孢子表面发生了药物单层的浓度依赖性形成。据此计算，十六烷基氯化吡啶、西曲溴铵和苯扎氯铵吸附在单个芽生孢子表面的分子数分别为1.33×10¹²、3.17×10¹²和2.32×10¹²。这些差异很可能是由于每种QAC的阳离子氮原子及其伴随的亲脂部分在芽生孢子表面的取向不同所致。将这些观察结果与十六烷基氯化吡啶和西曲溴铵已知的抗黏附作用联系起来，可以得出结论，QAC对芽生孢子表面的单层覆盖并不能解释所观察到的黏附减少现象。这表明抗黏附作用是由于与芽生孢子表面的黏附素直接相互作用或空间位阻所致。
