Chemical Industry and Chemical Engineering Quarterly (Sep 2011)
EXTRACTIVE SPECTROPHOTOMETRIC DETERMINATION OF QUETIAPINE FUMARATE IN PHARMACEUTICALS AND HUMAN URINE USING CALMAGITE AS AN ION-PAIR REAGENT
Abstract
Quetiapine fumarate (QTF) is an antipsychotic drug belonging to the benzisoxazole derivatives indicated for the treatment of schizophrenia. A sensitive and selective method based on dichloromethane-extractable ion-pair of QTF with calmagite (CGT), which exhibited an absorption maximum at 490 nm, is described. At this wavelength, Beer’s law is obeyed over the concentration range of 3.0–30.0 µg ml-1. The apparent molar absorptivity, limit of detection (LOD) and quantitation (LOQ) values are 1.32×104 l mol-1 cm-1, 0.27 and 0.81 µg ml-1, respectively. The reaction is extremely rapid at room temperature and the absorbance values remain unchanged up to 19 h. The precision results, expressed as intra-day and inter-day relative standard deviation values, are satisfactory (RSD ≤ 2.2%). The accuracy is satisfactory as well (RE ≤ 2.44%). The method was successfully applied to the determination of QTF in pharmaceuticals and spiked human urine with satisfactory results. No interference was observed from common pharmaceutical adjuvants in tablets. Statistical comparison of the results with the official method showed an excellent agreement and indicated no significant difference in precision.
