title: Determination of ethambutol hydrochloride in the combination tablets by precolumn derivatization.
abstract: A new high-performance liquid chromatography method for the quantitative determination of ethambutol hydrochloride in combination tablets is presented. Ethambutol is derivatized with phenylethylisocyanatate at room temperature (22 +/- 2 degrees C) for 5 min. Separation is performed by a C(18) column using methanol-water-glacial acetic acid (70:30:0.2, v/v/v) as the mobile phase. The method is linear for drug concentrations in the range of 20-120 microg/mL (r=0.9995). The intra- and inter-day precisions are lower than 1.46% and 2.22%, respectively. The average recovery of the samples at three levels is 99.8%. The results show that derivatization of ethambutol is stable at 30 degrees C for 24 h. This method is simple, rapid, and stable in the presence of common excipients and antituberculosis drugs in the tablets.
authors.affiliation: Department of Pharmacy, The Northern Hospital, Wenhua Road 83, Shenyang, 110016, P.R. China. ymyx@sina.com
authors.forename: Ming
authors.initials: M
authors.lastname: Yan
authors.forename: Tao
authors.initials: T
authors.lastname: Guo
authors.forename: Hongtao
authors.initials: H
authors.lastname: Song
authors.forename: Qingchun
authors.initials: Q
authors.lastname: Zhao
authors.forename: Yin
authors.initials: Y
authors.lastname: Sui
mesh_terms: D000995:Antitubercular Agents / Q000032:analysis*; D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D004338:Drug Combinations; D004977:Ethambutol / Q000032:analysis*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D021241:Spectrometry, Mass, Electrospray Ionization; D013056:Spectrophotometry, Ultraviolet; D013607:Tablets / Q000737:chemistry*
chemical_list: D000995:Antitubercular Agents; D004338:Drug Combinations; D013607:Tablets; D004977:Ethambutol