Novel spectrophotometric methods for determination of desloratidine in pharmaceutical formulations based on charge transfer reaction

AbstractA facile, rapid, sensitive and validated spectrophotometric methods for the determination of desloratidine (DES) in pure and in dosage forms is described. The methods are based on the formation of charge transfer complexes between DES and the chromogenic reagents alizarin (I), alizarin red S (II) and quinalizarin (III) producing charge transfer complexes in alcoholic medium which showed an absorption maximum at 528, 505 and 560nm for I, II and III, respectively. The optimization of the reaction conditions such as the type of solvent, reagent concentration and reaction time was investigated. Beer's law is obeyed in the concentration ranges 1.0–16, 0.5–12 and 2.0–20μgmL−1 for I, II and III, respectively. The molar absorptivity, Sandell sensitivity, detection and quantification limits are also calculated. The correlation coefficient was ⩾0.9993 (n=6) with a relative standard deviation (R.S.D.) of ⩽1.13. The methods are successfully applied to the determination of DES in pharmaceutical formulations and the validity assesses by applying the standard addition technique, which compared with those obtained using the reported method