Carnevale L
J Pharm Sci. 1983 Feb;72(2):196-8. doi: 10.1002/jps.2600720227.
The separation and simultaneous determination, by high-performance liquid chromatography, of acetaminophen (I), guaifenesin (II), pseudoephedrine hydrochloride (III), and pholcodine (IV), together with a series of parabens (methyl to butyl, V-VIII) in a cough mixture, has been demonstrated using a chemically bonded octadecylsilane stationary phase with a mobile phase of methanol-water-acetic acid (45:55:2) containing the ion-pairing agent octanesulfonic acid. Retention volumes for the active ingredients were 3.8 ml, 5.4 ml, 9.4 ml, and 15.6 ml for compounds I-IV, respectively. Corrected retention volumes for the parabens [5.4 ml for methyl (V), 9.6 ml for ethyl (VI), 18.5 ml for propyl (VII), and 37.9 ml for butyl (VIII)] showed an exponential relationship with chain length of the esterifying alcohols. Excipients did not interfere with the estimation of any of the compounds, hence pretreatment of the sample was unnecessary. Average recoveries of the active ingredients and of the parabens from laboratory prepared samples were essentially 100% of theoretical with standard deviations of 1.7, 0.3, 1.5, 0.3, 0.3, 3.3, 0.7, and 2.7% for I-VIII, respectively.
采用十八烷基硅烷化学键合固定相，以含有离子对试剂辛烷磺酸的甲醇 - 水 - 乙酸（45:55:2）为流动相，通过高效液相色谱法，已证明可对止咳合剂中的对乙酰氨基酚（I）、愈创甘油醚（II）、盐酸伪麻黄碱（III）、福尔可定（IV）以及一系列对羟基苯甲酸酯（甲基至丁基，V - VIII）进行分离和同时测定。化合物I - IV的活性成分保留体积分别为3.8 ml、5.4 ml、9.4 ml和15.6 ml。对羟基苯甲酸酯的校正保留体积[甲基（V）为5.4 ml，乙基（VI）为9.6 ml，丙基（VII）为18.5 ml，丁基（VIII）为37.9 ml]与酯化醇的链长呈指数关系。辅料不干扰任何化合物的测定，因此无需对样品进行预处理。从实验室制备的样品中，活性成分和对羟基苯甲酸酯的平均回收率基本上为理论值的100%，I - VIII的标准偏差分别为1.7%、0.3%、1.5%、0.3%、0.3%、3.3%、0.7%和2.7%。
