Abstract
A stability-indicating LC method for the estimation of related substances of duloxetine hydrochloride
Author(s): K.Rama Seshaiah, M.Vishnumurthy, V.Krishna Reddy, V.V.N.K.V.Prasadaraju, Katkam Srinivas, K.Mukkanti, V.Ranga ReddyA simple, inexpensive and rapid LC method has been developed for the quantative determination of duloxetine , an anti-depressant drug. Themethod can also be employed for the determination of duloxetine and its impurities in the bulk drug. Degradation studies were performed on the bulk drug by heating to 105ï‚°C, exposure to UV light at an energy of 200Watt hours/ m2and toVisible light at an illumination of not less than 1.2million lux hours, acid (0.1 N hydrochloric acid), base (5.0N sodium hydroxide) aqueous hydrolysis and oxidationwith 6.0%v/v hydrogen peroxide. Considerable degradation was observed under acid, base and oxidation conditions. Good resolution between the peaks corresponding to impurities produced during synthesis, degradation products and the analyte was achieved on a Symmetry C8 LC column using a mobile phase consisting of a mixture of aqueous potassium dihydrogen phosphate, Sodium-1-octane sulfonate and acetonitrile. The degradation samples were assayed against the reference standard of duloxetine and the mass balance in each case was close to 99.9%. Validation of the method was carried out as per ICH requirements.
