Spectrophotometric determination of trifluoperazine HCl and isopropamide iodide in binary mixture using second derivative and second derivative of the ratio spectra methods

Two methods are presented for the simultaneous determination of trifluopera zine hydrochloride and isopropamide iodide in binary mixture. The first met hod depends on second derivative (D-2) ultraviolet spectrophotometry, with zero crossing and peak to base measurement. The second derivative amplitude s at 270.4 and 230.2 nm were selected for the assay of trifluoperazine hydr ochloride and isopropamide iodide, respectively. The second method depends on second derivative of the ratio spectra by division of the absorption spe ctrum of the binary mixture by a normalized spectrum of one of the componen ts and then calculating the second derivative of the ratio spectrum. The se cond derivative of the ratio amplitudes at 257 and 228 nm were selected for the determination of trifluoperazine hydrochloride and isopropamide iodide , respectively. The two proposed methods were successfully applied to the d etermination of the two drugs in laboratory prepared mixtures and in commer cial tablets. (C) 2001 Elsevier Science B.V. All rights reserved.