Simultaneous densitometric determination of indomethacin and its degradation products, 4-chlorobenzoic acid and 5-methoxy-2-methyl-3-indoleacetic acid, in pharmaceutical preparations.
A densitometric method was developed for the identification and determination of indomethacin and its degradation products, 4-chlorobenzoic acid and 5-methoxy-2-methyl-3-indoleacetic acid, in pharmaceuticals. To separate these compounds, silica gel-coated thin-layer chromatography plates and the following mobile phase were used: 2-propanol-25% ammonia-water (8 + 1 + 1, v/v). UV densitometric measurements were made by comparing the absorption spectra and Rf values of appropriate standards with the pharmaceutical preparations examined. The conditions for separation were established and a low detection limit was obtained. Average recoveries were 100.69, 90.09, and 91.17% for indomethacin, 4-chlorobeznzoic acid, and 5-methoxy-2-methyl-3-indoleacetic acid, respectively.
Krzek
J
J
Jagiellonian University, Collegium Medicum, Department of Inorganic and Analytical Chemistry, Kraków, Poland. mfczekaj@cyf-kr.edu.pl
Starek
M
M
D000894:Anti-Inflammatory Agents, Non-Steroidal / Q000032:analysis*; D002723:Chlorobenzoates / Q000032:analysis; D002853:Chromatography, Liquid; D002855:Chromatography, Thin Layer; D003720:Densitometry / Q000379:methods*; D004340:Drug Contamination; D006801:Humans; D007210:Indoleacetic Acids / Q000032:analysis; D007213:Indomethacin / Q000032:analysis*; D004364:Pharmaceutical Preparations / Q000032:analysis*
D000894:Anti-Inflammatory Agents, Non-Steroidal; D002723:Chlorobenzoates; D007210:Indoleacetic Acids; D004364:Pharmaceutical Preparations; C030098:5-methoxy-methylindoleacetic acid; C040768:4-chlorobenzoic acid; D007213:Indomethacin