UV-Visible Spectrophotometric Determination of Triflupromazine Hydrochloride using Cerium(IV) Ammonium Nitrate in Pure and Pharmaceutical Forms

This study presents a novel, rapid, and cost-effective UV-visible spectrophotometric method for the quantitative determination of triflupromazine hydrochloride (TFM·HCl) in both pure and pharmaceutical forms. The method is based on the oxidative coupling reaction between TFM·HCl and diammonium cerium(IV) nitrate (CAN), resulting in the formation of a stable, colored complex. The experimental parameters influencing the reaction, such as pH, ion concentration, volume, reaction time, temperature, and order of addition, were optimized. Under the optimal conditions, the reaction product exhibited a maximum absorbance at 498.6 nm, with excellent adherence to the Beer–Lambert law over the concentration range of 2–70 μg mL-¹. The stoichiometric ratio between TFM·HCl and CAN was determined to be 1:1. The developed method demonstrated good sensitivity, with a calculated limit of detection (LOD) of 0.244 μg∙mL-¹ and a limit of quantification (LOQ) of 0.813 μg∙mL-¹. Sandell’s sensitivity was found to be 0.1075 μg∙cm-². Moreover, a redshift of 220.6 nm was observed in the absorption spectrum of the product compared to the parent compound, confirming the formation of a new chromophore. These findings highlight the method’s potential applicability in routine pharmaceutical analysis.