Two simple, rapid and accurate spectrophotometric procedures are proposed for
the determination of quetiapine fumarate (QTF) in pharmaceuticals and in
spiked human urine. The methods are based on charge transfer complexation
reactions of free base form of the drug (quetiapine, QTP), as n-electron
donor (D), with either p-chloranilic acid (p-CAA) (method A) or
2,3-dichloro-5,6-dicyanoquinone (DDQ) (method B) as ?-acceptors (A). The
coloured charge transfer complexes produced exhibit absorption maxima at 520
and 540 nm, in method A and method B, respectively. The experimental
conditions such as reagent concentration, reaction solvent and time have been
carefully optimized to achieve the maximum sensitivity. Beer?s law is obeyed
over the concentration ranges of 8.0 - 160 and 4.0 - 80.0 ?g ml-1, for method
A and method B, respectively. The calculated molar absorptivity values are
1.77 ? 103 and 4.59 ? 103 l mol-1cm-1, respectively, for method A and method
B. The Sandell sensitivity values, limits of detection (LOD) and
quantification (LOQ) have also been reported. The stoichiometry of the
reaction in both cases was accomplished adopting the limiting logarithmic
method and was found to be 1: 2 (D: A). The accuracy and precision of the
methods were evaluated on intra-day and inter-day basis. The proposed methods
were successfully applied for the determination of QTF in pharmaceutical
formulations and spiked human urine.
Spectrophotometric Determination of Domperidone in its Pharmaceutical Formulation Through Charge Transfer Complexation Reactions
