Validated Spectrophotometric Methods Based on Charge Transfer Complexation Reactions for the Quantification of Antimalarial Drug: Chloroquine Phosphate in Pure and Dosage Forms

Abstract

Chloroquine phosphate (CQP), an antimalarial medication, has been determined using two straightforward, sensitive, quick, and verified spectrophotometric techniques. The procedures were based on the generation of charge transfer complexes in methanol utilizing alizarin red S (ARS) and quinalizarin (Quinz) as chromogenic reagents, respectively, with absorption maxima at 560 and 531 nm for each. Investigated was the optimization of the reaction conditions, including the kind of solvent, reagent concentration, and reaction time. Beer's law is effectively observed using Quinz and ARS, respectively, in the concentration ranges of 1.0-20 and 1.0-16 g mL-1, with strong correlation coefficients (r2 ≥0.9995) and low relative standard deviations (RSD%≤ 1.07). Calculations were also made for the molar absorptivity, Sandell sensitivity, detection, and quantification limitations. The approaches were successfully used to identify CQP in pharmaceutical formulations, and the standard addition technique. was used to evaluate the methods' validity. Results from the suggested procedures for pure CQP and dosage forms were in good agreement with those from the previously described approach.