TY - JOUR AU - Green, Michael D. AU - Nettey, Henry AU - Wirtz, Robert A. T1 - Determination of Oseltamivir Quality by Colorimetric and Liquid Chromatographic Methods T2 - Emerging Infectious Disease journal PY - 2008 VL - 14 IS - 4 SP - 552 SN - 1080-6059 AB - We developed a colorimetric and chromatographic assay for oseltamivir to assess the authenticity of Tamiflu (F. Hoffmann-La Roche Ltd., Basel, Switzerland) because of a growing concern about counterfeit oseltamivir. The colorimetric assay is quantitative and relies on an extractable colored ion-pair complex of oseltamivir with Congo red or bromochlorophenol blue. The reverse-phase chromatographic assay uses an alkaline mobile phase with UV detection. Both methods were evaluated for variability and selectivity and subsequently applied to batches of oseltamivir products acquired through the Internet. The Congo red test showed greater assay sensitivity, linearity, and accuracy. Colorimetric and chromatographic analysis showed all batches of oseltamivir product were within ±15% of the stated amount of active ingredient. KW - Oseltamivir KW - bird flu KW - avian influenza KW - colorimetric KW - chromatography KW - research DO - 10.3201/eid1404.061199 UR - https://wwwnc.cdc.gov/eid/article/14/4/06-1199_article ER - End of Reference