Kwong E, Pillai G K, McErlane K M
J Pharm Sci. 1982 Jul;71(7):828-30. doi: 10.1002/jps.2600710730.
Indomethacin and its impurities in suppository and capsule formulations were quantitatively determined by HPLC using a reversed-phase, octadecyl column and a mobile phase of methanol-water-acetonitrile-acetic acid (55:35:10:1). Analysis of the suppository formulations provided a mean potency for indomethacin of 103.8%. The same formulation was found to contain 4-chlorobenzoic acid (0.02%), 5-methoxy-2-methyl-3-indoleacetic acid (0.07%), 4-chlorobenzoic acid-alpha-monoglyceride (0.39%), and indomethacin-alpha-monoglyceride (0.9%) as impurities. The latter two impurities were a result of the interaction of indomethacin and 4-chlorobenzoic acid with glycerin used in the suppository base. Capsule formulations were likewise assayed with an average potency of 99.9 and 101.5% for 25- and 50-mg dosage forms, respectively. Only one of the two capsule formulations examined contained detectable quantities of 4-chlorobenzoic acid (0.05%).
采用高效液相色谱法，使用反相十八烷基柱，以甲醇 - 水 - 乙腈 - 乙酸（55:35:10:1）作为流动相，对栓剂和胶囊制剂中的吲哚美辛及其杂质进行定量测定。栓剂制剂分析显示吲哚美辛的平均效价为103.8%。发现同一制剂含有4 - 氯苯甲酸（0.02%）、5 - 甲氧基 - 2 - 甲基 - 3 - 吲哚乙酸（0.07%）、4 - 氯苯甲酸 - α - 单甘油酯（0.39%）和吲哚美辛 - α - 单甘油酯（0.9%）作为杂质。后两种杂质是吲哚美辛和4 - 氯苯甲酸与栓剂基质中使用的甘油相互作用的结果。对胶囊制剂同样进行了分析，25毫克和50毫克剂型的平均效价分别为99.9%和101.5%。所检测的两种胶囊制剂中只有一种含有可检测量的4 - 氯苯甲酸（0.05%）。
