Sireesha Dodda*, Raj Narayana K and Ajitha Makula Pages 1 - 10 ( 10 )
Introduction: A selective, sensitive, precise and rapid analytical method using liquid chromatography-tandem mass spectrometry (LC/MS/MS) for simultaneous determination of oseltamivir and oseltamivir carboxylic acid in plasma has been developed and validated, using oseltamivir-D5 and oseltamivir acid-D3 as internal standards. Method: The analytes were extracted from 300µL of human plasma using solid phase extraction technique. A mixture of methanol and 0.1% formic acid (60:40, v/v) was used as mobile phase at a flow rate of 0.7mL/min, to separate the analytes on Zorbax SB-C18 (50x4.6mm, 3.5µm) analytical column. Results: The calibration curves obtained were linear over the concentration ranges of 0.5-200ng/mL and 2.0-800ng/mL for oseltamivir and oseltamivir carboxylic acid respectively. A run time of 2.5min makes it possible to analyze more than 350 plasma samples in a day, thereby increasing the productivity. Conclusion: The present method was applied successfully to a clinical pharmacokinetic study in South Indian male subjects with 75mg oseltamivir phosphate capsule under fasting conditions and the results were authenticated by incurred sample reanalysis.
Oseltamivir, Oseltamivir carboxylic acid, bioanalytical method, LC/MS/MS, pharmacokinetics
Department of Pharmacy, Anurag group of Institutions (Formerly Lalitha College of Pharmacy), Hyderabad-500088, Department of pharmaceutical Sciences, IST, JNTUH, Hyderabad- 500085, Biotechnica Pharma, Hyderabad – 500085