Development and Validation of a Stability Indicating Liquid Chromatographic Method for the Determination of Milnacipran in Bulk and its Formulations

A simple, sensitive and rapid isocratic reversed phase (RP) liquid chromatographic (LC) method was developed for the estimation of milnacipran in bulk and its formulations. Separations were carried out using the mobile phase consisting of 25mM phosphate buffer, acetonitrile and methanol on LiChrospher® 100 RP-18 analytical column at a flow rate of 1.0 mL/min and detection wavelength of 220 nm. The method developed as per the ICH guidelines, exhibited linearity over the analytical range of 25-3000 ng/mL with regression equation y = 801.1 x - 10767 [mean peak area = 801.1 concentration (ng/mL) - 10767] and regression coefficient, r2 = 0.999. The method demonstrated selectivity with no interfering peaks eluting in the vicinity of the drug peak and was consistent with good recovery. Forced degradation studies were also performed on the drug samples to demonstrate the stability indicating power of the method. The developed method being sensitive, precise and accurate in the studied range, can be employed for the routine estimation of in bulk and its formulations.