Abstract

DETERMINATION OF PIMAVANSERIN IN PURE AND PHARMACEUTICAL FORMS USING ACIDIC TRIPHENYLMETHANE DYES: A SPECTROPHOTOMETRIC STUDY

Nandu Vadla and Veeraiah Tadooru*

ABSTRACT

Four new methods have been developed for the estimation of Pimavanserin based on the interaction of Pimavanserin with triphenyl methane dyes viz., bromocresol green (BCG), bromocresol purple (BCP), bromophenol blue (BPB) and bromothymol blue (BTB) to form ion-pair complexes in acidic medium. The extracted ion-pair complexes formed with BCG, BCP, BPB and BTB showed absorbance maxima at 420, 418, 412 and 408 nm respectively. The stoichiometry of the ion- pair complex is found to be 1:1 in each case. Beer’s law is obeyed in the concentration ranges 2.0-25, 3.0-30, 3.5-35 and 4.0-40 μg/ml with BCG, BCP, BPB and BTB respectively. The effect of concentration of dye, pH, and interference of excipients have been studied for optimization. The limits of detection and quantification have been determined for all the four methods and the results of analysis have been validated statistically as per the guidelines of ICH through recovery studies. The ion-pair complexes of Pimavanserin and their maximum absorbances offer a basis for the determination of the drug. The developed methods are simple, sensitive, reproducible and can be used for routine analysis of Pimavanserin in pure and pharmaceutical dosage forms.

Keywords: Spectrophotometry, Pimavanserin, Bromocresol green, Bromocresol purple, Bromophenol blue, Bromothymol blue, Ion-pair complex, Validation.