Innovative spectrofluorometric protocol based on micro-environment improvement for determination of Quetiapine in dosage forms and rat plasma.

Abstract

Quetiapine (QUT) is an atypical antipsychotic drug indicated for the treatment of schizophrenia and acute manic episodes associated with bipolar disorders. A simple, rapid, and highly sensitive micellar spectrofluorometric method has been developed and validated for quantitation of QUT in its pharmaceutical formulations with application to content uniformity test, in presence of its degradation product and in rat plasma. The proposed method was based on the enhancement of the fluorescence intensity of QUT in 2% v/v tween 80 micellar solution. The fluorescence intensity was measured at 372nm after excitation at 261nm. A linear relationship was achieved between the fluorescence intensity and the drug concentration in the range of 20-1000ng/mL with 18.5 and 6.3ng/mL as limits of quantitation and detection, respectively. The proposed method was extended to study the stability of QUT after its exposure to different forced degradation conditions such as; acidic, alkaline, oxidative, photolytic and thermal conditions according to ICH guidelines. The study revealed that QUT is stable under all the of these conditions except the oxidative one. Furthermore, the high sensitivity of the micellar method permits its application for determination of QUT in rat plasma with good percentage recovery as well as determination of Cmax.