RP-HPLC Method for Determination of Oseltamivir Phosphate in Capsules and Spiked Plasma

Abstract

A new, sensitive RP-HPLC method was developed for the determination of oseltamivir phosphate in capsules and plasma. The method was based on the reaction of the drug with 4-chloro-7-nitrobenzofurazan in borate buffer solution of pH 8.50. Isocratic chromatography was performed on a C₁₈ column with acetonitrile–10 mM nitric acid (pH 3, 60 + 40, v/v) as the mobile phase with fluorescence detection (λex: 470 nm, λem: 541 nm). Mexiletine hydrochloride was used as an internal standard. Analytical parameters were evaluated. The calibration range was linear from 50.0–750.0 ng/ml. The mean percentage recovery in capsules and plasma were 99.95% and 95.42%, respectively.

Keywords:

• 4-Chloro-7-nitrobenzofurazan
• Drug analysis
• HPLC
• Oseltamivir phosphate
• Plasma

This work was supported by Research Fund of the Istanbul University. Project number: 478/27122005.