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Determination of oseltamivir quality by colorimetric and liquid chromatographic methods.

Green MD, Nettey H, Wirtz RA - Emerging Infect. Dis. (2008)

Bottom Line: Hoffmann-La Roche Ltd., Basel, Switzerland) because of a growing concern about counterfeit oseltamivir.Both methods were evaluated for variability and selectivity and subsequently applied to batches of oseltamivir products acquired through the Internet.Colorimetric and chromatographic analysis showed all batches of oseltamivir product were within +/-15% of the stated amount of active ingredient.

View Article: PubMed Central - PubMed

Affiliation: Centers for Disease Control and Prevention, Atlanta, GA 30333, USA. mgreen@cdc.gov

ABSTRACT
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.

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Structure of oseltamivir.
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Related In: Results  -  Collection


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Figure 1: Structure of oseltamivir.

Mentions: Simple and affordable colorimetric assays provide a practical means to rapidly monitor drug quality in resource-poor areas. Because oseltamivir phosphate (Figure 1) possesses amine groups, the protonated form may act as a cationic site for anionic dyes such as Congo red and bromochlorophenol blue to produce colored ion-pairing complexes. Congo red has been used in colorimetric determinations of chitosan and poly (N-vinyl-2-pyrrolidone) while bromophenol blue has been used in colorimetric assays for antimalarial drugs (4-6). Therefore, our objective was to develop and evaluate a colorimetric technique, as well as a high-performance liquid chromatographic method (HPLC), to measure the concentration of oseltamivir phosphate in pharmaceutical preparations. The HPLC method described here was used to validate the colorimetric test. To date, there are few published reports of HPLC methods for measuring oseltamivir. A sensitive HPLC-mass spectrometry assay for oseltamivir carboxlate in plasma and urine and an HPLC assay for oseltamivir phosphate in pharmaceutical preparations have been described (7,8). In our study, we validated, compared, and applied colorimetric and HPLC techniques to the testing of alleged Tamiflu product purchased through the Internet.


Determination of oseltamivir quality by colorimetric and liquid chromatographic methods.

Green MD, Nettey H, Wirtz RA - Emerging Infect. Dis. (2008)

Structure of oseltamivir.
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC2570928&req=5

Figure 1: Structure of oseltamivir.
Mentions: Simple and affordable colorimetric assays provide a practical means to rapidly monitor drug quality in resource-poor areas. Because oseltamivir phosphate (Figure 1) possesses amine groups, the protonated form may act as a cationic site for anionic dyes such as Congo red and bromochlorophenol blue to produce colored ion-pairing complexes. Congo red has been used in colorimetric determinations of chitosan and poly (N-vinyl-2-pyrrolidone) while bromophenol blue has been used in colorimetric assays for antimalarial drugs (4-6). Therefore, our objective was to develop and evaluate a colorimetric technique, as well as a high-performance liquid chromatographic method (HPLC), to measure the concentration of oseltamivir phosphate in pharmaceutical preparations. The HPLC method described here was used to validate the colorimetric test. To date, there are few published reports of HPLC methods for measuring oseltamivir. A sensitive HPLC-mass spectrometry assay for oseltamivir carboxlate in plasma and urine and an HPLC assay for oseltamivir phosphate in pharmaceutical preparations have been described (7,8). In our study, we validated, compared, and applied colorimetric and HPLC techniques to the testing of alleged Tamiflu product purchased through the Internet.

Bottom Line: Hoffmann-La Roche Ltd., Basel, Switzerland) because of a growing concern about counterfeit oseltamivir.Both methods were evaluated for variability and selectivity and subsequently applied to batches of oseltamivir products acquired through the Internet.Colorimetric and chromatographic analysis showed all batches of oseltamivir product were within +/-15% of the stated amount of active ingredient.

View Article: PubMed Central - PubMed

Affiliation: Centers for Disease Control and Prevention, Atlanta, GA 30333, USA. mgreen@cdc.gov

ABSTRACT
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.

Show MeSH