Evaluation of the on-off fluorescence method for facile measurement of vilazodone in pharmaceutical dosage form; Application to content uniformity testing and greenness evaluation.

Vilazodone is a recently approved antidepressant medicine used for treating major depressive disorder. A simple, extremely sensitive, accurate and green spectrofluorimetric method was constructed for its determination through formation of ion-pair complex with erythrosine B. The formation of ion-pair complex lowers the dye's native fluorescence emission measured at 552 nm (λ ex = 530 nm). In terms of analysis, the system's parameters for producing the vilazodone-erythrosine B complex have been optimized. The reaction was carried out in Teorell-Stenhagen buffering solution (pH 4.6). The fluorescence emission intensity of the dye decreased linearly in the range of 20 - 600 ng mL-1 and the correlation coefficient was 0.9999. The quantitation and detection limit values were 18.5 and 6.1 ng mL-1, respectively. The proposed strategy has been validated according to the ICH criteria. The proposed technique was thoroughly employed for evaluating vilazodone in raw material and pharmaceutical tablet dosage form. Furthermore, it was also successfully used for content uniformity testing. Lastly, using four advanced tools namely the Eco-Scale, the National Environmental Method Index (NEMI), the Green Analytical Procedure Index (GAPI), and the Analytical Greenness metric approach (AGREE), the greenness of the established technique was evaluated.

Development and Validation of a Stability-Indicating Liquid Chromatographic Method for Estimating Vilazodone Hydrochloride in Pharmaceutical Dosage Form Using Quality by Design.

A stability-indicating liquid chromatographic method was developed employing the principles of quality by design (QbD) to quantify vilazodone hydrochloride (VLN) in pharmaceutical dosage form. A Box-Behnken experimental design was employed to establish optimum conditions including method robustness by selecting organic phase proportion (%), mobile phase flow rate (mL/min) and pH of buffer as the factors, to study their effect on plate number as the response variable. Chromatography was performed on a C-18 column using methanol:phosphate buffer of pH 7.0 (85:15, v/v) as the mobile phase at a flow rate of 1.2 mL/min with photo diode array (PDA) detection at 285 nm. Calibration curve was linear over 5-80 µg/mL with values of accuracy within 99.4-100.8%. The limit of detection and quantification were found to be 1.5 and 5.0 µg/mL, respectively. The developed method revealed high specificity for VLN and its degradation products formed during forced degradation conditions. Furthermore, control strategies were developed based on system suitability test result. The QbD-based developed liquid chromatographic method was found suitable for routine analysis of VLN in bulk drug and pharmaceutical dosage form.