Development and Validation of New RP-HPLC Method for Simultaneous Determination of Nortriptyline and Gabapentin in Combined Dosage Form

A simple, precise, rapid and accurate reverse phase high performance liquid chromatography method was developed for simultaneous estimation of Nortriptyline and Gabapentin in dosage form. Chromatographic separation was performed on Zorbax C18, (250 X 4.6mm, 5μm) column, with mobile phase comprising of mixture of buffer (pH 4.2) and acetonitrile in the ratio of 70:30v/v, at the flow rate 1.0 ml/min. The detection was carried out at 253nm. The retention times of Nortriptyline and Gabapentin were found to be 2.866 and 3.629 mins respectively with a run time of 6 mins, respectively. As per ICH guidelines the method was validated for linearity, accuracy, precision, limit of detection and limit of quantitation, robustness and ruggedness. Linearity of Nortriptyline was found in the range of 60-180μg/mL and that for Gabapentin was found to be 300-900μg/mL. The correlation coefficient for Nortriptyline and Gabapentin were 1.000 and 0.9999 respectively. The LOD values for nortriptyline and gabapentin were found to be 0.0013µg/mL and 0.007µg/mL, respectively and the LOQ values 0.004µg/mL and 0.024µg/mL respectively.