Analysis of Pyridostigmine Bromide in Human Plasma and its Application in Bioequivalence Studies

Abstract

A high performance liquid chromatographic (HPLC) method was developed using liquid‐liquid extraction and ultra‐violet detection for quantifying pyridostigmine bromide in human plasma. Liquid chromatography was performed on a BDS Hypersil C18 coulmn (5 µm, 250×4.6 mm i.d.) using an isocratic mobile phase comprised of acetonitrile‐5 mM potassium dihydrogen phosphate (40∶60, v/v) and the eluent was detected at 269 nm by UV. Clonazepam was used as the internal standard. The limit of quantification was 20 ng/mL using 1 mL plasma. The intra and inter‐day precision expressed as the relative standard deviation was less than 15%. The assay was applied to the analysis of samples from a pharmacokinetic study. Following the oral administration of 60 mg pyridostigmine bromide (test) to volunteers, the maximum plasma concentration (Cmax), area under the curve (AUC) and elimination half‐life (t_1/2) were 176.03±9.176 ng/mL, 819.999±109.64 ng hr/mL and 3.787±0.08 hr, respectively. The method was demonstrated to be highly feasible and reproducible for pharmacokinetic studies of pyridostigmine bromide in humans.

Keywords:

• Pyridostigmine bromide
• Pharmacokinetics
• HPLC

Acknowledgments

The authors are thankful to Department of Science and Technology (DST), New Delhi for the financial support provided by them for carrying out this study and also to Shree Ganesh Pharmaceuticals Ltd., Mumbai, for supplying the samples.