Sensitive and Selective Extractive Spectrophotometric Method for the Determination of Hydroxyzine Dihydrochloride in Pharmaceuticals

Abstract

Hydroxyzine dihydrochloride (HDH), a piperazine H1-receptor antagonist and antihistamine, is a rapid acting anxiolytic used principally as an anti-emetic. A sensitive, selective, and precise and accurate spectrophotometric method based on the formation of an ion-pair with orange II (ORG II) as ion-pair complexing agent was developed and validated for the determination of HDH in pharmaceuticals. The chloroform-extractable ion-pair complex exhibited an absorption maximum at 480 nm. Optimization of different experimental conditions is described. Beer’s law is obeyed in the range of 1.5-15 μg mL-1 with an apparent molar absorptivity value of 2.07 x 104 L mol-1 cm-1 and Sandell’s sensitivity value of 0.0216 μg cm-2. The limit of detection (LOD) and limit of quantification (LOQ) are 0.14 and 0.41 μg mL-1, respectively. A Job’s plot of absorbance versus molar ratio of HDH to ORG II indicated (1:2) stoichiometric ratio. Within- and between-day relative standard deviations at three different concentration levels were < 3%. The developed method was successfully applied to commercial tablets. The results obtained were in good agreement with those obtained using the official method.
 No interference was encountered from co-formulated substances.
 Recoveries were 96-109 %.