Development of a high-performance liquid chromatographic-mass spectrometric assay for the specific and sensitive quantification of Ro 64-0802, an anti-influenza drug, and its pro-drug, oseltamivir, in human and animal plasma and urine

J Chromatogr B Biomed Sci Appl. 2000 Aug 18;745(2):373-88. doi: 10.1016/s0378-4347(00)00300-5.


Oseltamivir phosphate (Ro 64-0796/002) is a pro-drug of the anti-influenza neuraminidase inhibitor, Ro 64-0802, and as Tamiflu, has been developed for the treatment of both A and B strains of the disease. This paper describes an HPLC-MS-MS assay for both compounds in plasma and urine which fulfils all of the criteria for a good analytical method. It is sensitive with limits of quantification of 1 and 10 ng/ml for the pro-drug and active neuraminidase inhibitor, respectively. It is both accurate and precise with typical coefficients of variation from some 5,000 quality control samples of approximately +/-3 and +/-6%, respectively. Extensive stability studies have demonstrated the absence of significant problems associated with the decomposition of either compound, although ex vivo hydrolysis of Ro 64-0796 to Ro 64-0802 in rodent plasma has to be prevented by the use of the esterase inhibitor, dichlorvos.

MeSH terms

  • Acetamides / blood
  • Acetamides / pharmacokinetics*
  • Acetamides / urine
  • Animals
  • Antiviral Agents / blood
  • Antiviral Agents / pharmacokinetics*
  • Antiviral Agents / urine
  • Chromatography, High Pressure Liquid / methods*
  • Humans
  • Influenza, Human / drug therapy
  • Mass Spectrometry
  • Oseltamivir
  • Reference Standards
  • Reproducibility of Results
  • Sensitivity and Specificity


  • Acetamides
  • Antiviral Agents
  • Ro 64-0802
  • Oseltamivir