ABSTRACT
Three new simple, different and sensitive spectrophotometric methods are suggested for the determination of Dropropizine [DRO]. The first is based on the reduction of ferric into ferrous in presence of 0-phenanthroline by the mentioned drug to form a highly stable orange-red ferroin chelate[Fe-[Phen][3]][2+], measured at [lambda][max] 510.5 nm for zero-order [D[degree sign]] while the peak amplitude was measured at 537.5 the nm for the first derivative [D[1]] using distilled deionized water as a solvent. Beer's law was obeyed in the range of 0.5-2.2 micro g/ml for both D[degree sign] and D[1] with mean percentage recoveries of 100.08 +/- 1.370 and 100.03 +/- 1.064, respectively. The second method is based on the reaction of DRO with 7,7,8,8- tetracyanoquinodimethane [TCNQ] in acetonitrile solvent to form a highly stable charge transfer colored complex that was measured at 734.5 nm. Beer's law was obeyed in the range of 10-55 micro g/ml with mean percentage recovery of 99.93 +/- 1.070. The last method is based on the reaction of DRO with cerium [IV] ammonium sulphate in acidic medium to form a highly stable colored oxidative product that was measured at 486.5 nm. Beer's law was obeyed in a concentration range 145 - 335 micro g/ml with mean percentage recovery of 99.67 +/- 1.077. The optimum assay conditions and their applicability for the determination of the cited drug in pharmaceutical formulation were described. The proposed methods were statistically compared with the reported method revealing good accuracy and precision