New Derivative Spectrophotometric Methods for the Determination of Zolpidem Tartrate in Pharmaceutical Dosage Forms

Abstract

Two simple, rapid and sensitive first derivative spectrophotometric methods were developed for the determination of zolpidem tartrate in pharmaceutical formulations in phosphate buffer pH 8.0 and borate buffer pH 9.0. Beer's law was obeyed in a concentration range of 1-30 μg/mL in phosphate buffer pH 8.0 and borate buffer pH 9.0 respectively with correlation coefficient of r 2 =0.999 in both the methods. The linear regression equations are found to be y=0.008x+0.001 and y = 0.0094x + 0.0033 in phosphate and borate buffer respectively. The %RSD for intra-day and inter-day precision studies were found to be 0.23 and 0.56 in phosphate buffer pH 8.0 and 0.63 and 0.68 in borate buffer pH 9.0 respectively which is less than 2.0 indicating that the methods are precise. The %RSD in accuracy studies was also found to be less than 2.0. The proposed methods are suitable for the determination of zolpidem tartrate in pharmaceutical formulations. No interferences were observed from the excipients in the formulations. The methods were validated according to ICH guidelines.