Derivative spectrophotometric, thin layer chromatographic-densitometric and high performance liquid chromatographic determination of trifluoperazine hydrochloride in presence of its hydrogen peroxide induced-degradation product

Three methods are presented for the determination of trifluoperazine HCl in presence of its hydrogen peroxide induced degradation product. The first m ethod was based on measurement of first (D-1) and second (D-2) derivative a mplitudes of trifluoperazine HCl in 0.1 N hydrochloric acid at the zero cro ssing point of its sulfoxide derivative, main degradation product, (at 268. 4 and 262.5 nm for D-1 and D-2, respectively). The second method was based on the separation of trifluoperazine HCl from its sulfoxide derivative foll owed by densitometric measurement of the intact drug spot at 255 nm. The se paration was carried out on Merck aluminum sheet of silica gel 60 F-254, us ing chloroform-methanol (7:3 v/v) as mobile phase. The third method was bas ed on high performance liquid chromatographic separation of trifluoperazine HCl from its sulfoxide derivative on reversed phase, ODS column, using a m obile phase of acetonitrile-phosphate buffer pH 4.2 (60:40 v/v) at ambient temperature. Quantitation was achieved with UV detection at 255 nm based on peak area. The first derivative spectrophotometric method was utilized to investigate the kinetics of the hydrogen peroxide degradation process at di fferent temperatures. The apparent pseudo first-order rate constant, half l ife and activation energy were calculated. (C) 2002 Elsevier Science B.V. A ll rights reserved.