Development and Validation of a Reversed-Phase HPLC Method for the Estimation of Zolpidem in Bulk Drug and Tablets

E Konoz,M Bahrami-Zonoz,R Abdolahnejad,A H Mohsen Sarrafi

doi:10.1155/2013/357890

Abstract

In the present study an isocratic reversed-phase high-performance liquid chromatography method was developed for the estimation of zolpidem in bulk drug and pharmaceutical dosage forms. The quantification was carried out on C18columns. A mixture of acetonitrile-ammonium acetate (pH=8.0, 0.02 M) (60 : 40 v/v) was used as the mobile phase, at flow rate of 1.0 mL/min and the determination wavelength at 245 nm. The retention time of zolpidem was found to be 3–5 min. The validation of the proposed method was carried out for specificity, linearity, accuracy, precision, limit of detection, limit of quantification, and robustness. The linear dynamic range was from 2.5 to 30 μg mL−1. Regression equation was found to bey=0.1416x+0.0183with correlation coefficientr=0.9996. The percentage recovery obtained for zolpidem was greater than 96.5%. Limit of quantification and limit of detection were found to be 2.5 μg mL−1and 0.83 μg mL−1, respectively. The developed method can be used for routine quality control analysis of zolpidem in tablet formulations.

Highlights

Zolpidem, 2-(4-methyl phenyl) N, N-6-trimethyl-imidazol [1, 2-αα] pyridine-3-acetamide, an imidazopyridine derivative, is a nonbenzodiazepine hypnotic indicated for the shortterm treatment of insomnia
E free base has a molecular weight of 307.4, with the salt form having a formula weight of 764.9. e salt has an appearance of a white to off-white powder, with a melting point of 193–197∘C. e tartrate salt is slightly soluble in water (23 g/L at 20∘C), sparingly soluble in methanol, and practically insoluble in methylene chloride. e Ultraviolet (UV) spectrum of zolpidem in 0.1 N HCL exhibits the λλ maximum of 294 nm [1,2,3,4,5,6]
Several analytical methods have been reported for quanti cation of zolpidem in human body uids and organ samples including capillary electrophoresis (CE) [7], GC [8,9,10], HPLC [1, 3, 11,12,13,14,15,16,17], GC/MS [9, 18, 19], LC/MS [20], LC/MS/MS [21,22,23], and radioimmunoassay [24]

Summary

Introduction

2-(4-methyl phenyl) N, N-6-trimethyl-imidazol [1, 2-αα] pyridine-3-acetamide, an imidazopyridine derivative, is a nonbenzodiazepine hypnotic indicated for the shortterm treatment of insomnia. Zolpidem (Figure 1) behaves as a sleep inducer without the muscle relaxant and anticonvulsant effects of the benzodiazepines Zolpidem is not a difficult drug to extract, detect over the therapeutic range, or detect at overdose levels. It has been measured in various biological specimens using a variety of different analytical techniques. In the HPLC methods, the sensitivity of zolpidem is higher with uorimetric detection than with UV detection [25]. Among these technologies, LC/MS and GC/MS are very expensive and are not o en affordable for a common laboratory nowadays, and the derivative procedure made GC difficult to be a robust tool for monitoring zolpidem in many samples. E main objective of the present work was to develop simple, fast, inexpensive, sensitive, and accurate method which could be applied to analyses of zolpidem in pure form and in pharmaceutical dosage form

Experimental

Results and Discussion

Method Validation

Conclusions