Tropical Journal of Pharmaceutical Research

Original Research Article | OPEN ACCESS

Facile Colorimetric Determination of Duloxetine in Formulations Using Methyl Orange as Ion-Pairing Agent

Pushparaj Hemalatha^1,2, Mani Ganesh^1,2, Mei Mei Peng^1,2, Hyun Tae Jang^1,2

¹Department of Chemical Engineering, Hanseo University; ²Korea Carbon Capture & Sequestration R&D Centre, 360 Daegok-ri, Haemi-myun, Seosan-si 356 706, Chungcheongnam-do, South Korea.

For correspondence:- Hyun Jang Email: htjang@hanseo.ac.kr Tel:+82416601423

Received: 30 April 2012 Accepted: 27 December 2012 Published: 21 February 2013

Citation: Hemalatha P, Ganesh M, Peng MM, Jang HT. Facile Colorimetric Determination of Duloxetine in Formulations Using Methyl Orange as Ion-Pairing Agent. Trop J Pharm Res 2013; 12(1):93-97 doi: 10.4314/tjpr.v12i1.15

© 2013 The authors.
This is an Open Access article that uses a funding model which does not charge readers or their institutions for access and distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0) and the Budapest Open Access Initiative (http://www.budapestopenaccessinitiative.org/read), which permit unrestricted use, distribution, and reproduction in any medium, provided the original work is properly credited..

Abstract

Purpose: To develop a new and fully validated ion-pair spectrophotometric method for the determination of duloxetine hydrochloride (DX).

Methods: Ion-pair spectrophotometric method was employed for the determination of duloxetine hydrochloride (DX) in bulk and pharmaceutical formulations using acidic dye methyl orange (MO) as ion-pairing agent at pH 4 (phthalate buffer). The yellow ion-pair complex was extracted with chloroform and spectrophotometrically estimated at 420 nm. The developed method was validated according to ICH and USP guidelines.

Results: The ion-pair complex of DX and MO obeyed Beer’s law in the range of 2 - 20 μg mL^-1of DX with a correlation coefficient of 0.998. Recovery was good, with a relative standard deviation (%RSD) of 0.88 - 1.02; precision (inter-day, 0.878 and intra-day, 0.921) was also within validation limits. The limit of detection (LOD) and limit of quantitation (LOQ) were 0.25 and 4 μg mL^-1, respectively. The method developed was successfully applied to determine DX in a formulation.

Conclusion: The developed method is accurate, precise, rugged, robust and reproducible. It is also sensitive and specific for the determination of DX in bulk and formulation.

Keywords: Duloxetine, Methyl orange, Ion-pair, Validation, Spectrophotometry