title: Analysis of ketorolac and its related impurities by capillary electrochromatography.
abstract: Capillary electrochromatography (CEC) was employed for the assay of ketorolac (KT) and its known related impurities [1-hydroxy analog of ketorolac (HK), 1-keto analog of ketorolac (KK), ketorolac decarboxylated (DK)] in both drug substance and coated tablets. Detection was made at 323 nm and flufenamic acid was selected as internal standard. The experiments were performed in a 100 microm i.d. capillary packed with RP-18 silica particles (33.0, 24.5, 23.0 cm total, effective and packed lengths, respectively). The composition of the mobile phase was optimised by changing pH of the buffer and acetonitrile (ACN) content and by addition of other organic modifiers (methanol, ethanol, isopropanol, n-propanol) in order to evaluate the effect of these factors on the method performance (efficiency, retention and resolution). The optimum mobile phase consisted of a mixture of 50 mM ammonium formate buffer pH 3.5-water-acetonitrile (10:20:70, v/v/v), while voltage and temperature were set at 30 kV and 20 degrees C, respectively. Applying these conditions, all peaks were baseline resolved and the analysis was performed in less than 9 min. Selectivity, repeatability of retention time and peak area, detection and quantitation limits, linearity and range, precision and accuracy were also investigated. R.S.D. and bias values obtained for all the analytes were below 5% and sensitivity was satisfactory, thus the method was deemed suitable for pharmaceutical quality control. Applying the method to coated tablets, a recovery of 98.5+/-0.8% and an R.S.D. of 0.5% were found.
authors.affiliation: Institute of Chemical Methodologies, CNR, Area della Ricerca di Roma, Via Salaria km 29.300, 00016 Monterotondo Scalo, Rome, Italy.
authors.forename: Serena
authors.initials: S
authors.lastname: Orlandini
authors.forename: Sandra
authors.initials: S
authors.lastname: Furlanetto
authors.forename: Sergio
authors.initials: S
authors.lastname: Pinzauti
authors.forename: Giovanni
authors.initials: G
authors.lastname: D'Orazio
authors.forename: Salvatore
authors.initials: S
authors.lastname: Fanali
mesh_terms: D002138:Calibration; D020374:Chromatography, Micellar Electrokinetic Capillary / Q000379:methods*; D020910:Ketorolac / Q000032:analysis*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity
chemical_list: D020910:Ketorolac