Entrapment of FePO4 in a polymeric matrix and their application to FIA-spectrophotometric determination of thioridazine and chlorpromazine in pharmaceutical formulations

Abstract

The present article deals with an FIA-spectrophotometric[fn1] procedure for the determination of thioridazine hydrochloride and chlorpromazine hydrochloride based on the reaction of the drug with iron (III). The metalic reagent is released by an HCl solution when flowing through a solid-phase reactor containing FePO4, immobilized in a polymeric resin. The FIA manifold was of the merging-zones configuration in which sample and HCl [to release the iron (III)] were simultaneously injected; the assembly was provided with a homemade double-injection-valve device. The calibration graph was linear over the range 250–400 μg mL−1 and 250–500 μg mL−1 for thioridazine hydrochloride and chlorpromazine hydrochloride, respectively. The detection limit was of 8 μg mL−1 and a sample throughput of 28 h−1 for both drugs. The procedure was applied to the determination of both phenotiazines in pharmaceutical formulations. © 1998 John Wiley & Sons, Inc. Lab Robotics and Automation 10: 33–37, 1998