Specific high-performance liquid chromatography assay for determination of rifabutin plasma concentration following Extrelut column extraction.
A specific, precise and accurate assay for determination of rifabutin in human plasma using Extrelut column extraction was developed and validated. Rifabutin concentrations were calculated with a standard curve ranging from 5 to 800 ng ml(-1). using a split-curve approach. Chromatographic peaks were separated by means of a 5 microm Symmetry Shield RP8 using a KH2PO4 (0.05 M) buffer-acetonitrile mobile phase. Detection wavelength was set at 275 nm. Chromatography was carried out at room temperature (20-25 degrees C). The limit of quantification was 5 ng ml(-1). The recovery was over 71%. The intra-day precision of the assay was 5, 7, and 1% while the inter-day precision was 11.2, 8.1, and 5.8% at concentrations of 30, 150 and 500 ng ml(-1), respectively. The accuracy ranged from 99 to 108%. Forty of the drugs most commonly administered to HIV-positive patients were found not to interfere with the assay. The assay has been used in a comparative study of rifabutin pharmacokinetics in HIV-positive patients with or without wasting syndrome. reserved.
1st Department of Infectious Diseases, University of Genova, Ospedale San Martino, Italy.
G
G
Gatti
C R
CR
De Pascalis
F
F
Miletich
R
R
Casazza
D
D
Bassetti
D000904:Antibiotics, Antitubercular / Q000097:blood* / Q000493:pharmacokinetics; D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D015658:HIV Infections / Q000097:blood; D019247:HIV Wasting Syndrome / Q000097:blood; D006801:Humans; D015203:Reproducibility of Results; D017828:Rifabutin / Q000097:blood* / Q000493:pharmacokinetics; D012680:Sensitivity and Specificity; D013056:Spectrophotometry, Ultraviolet
D000904:Antibiotics, Antitubercular; D017828:Rifabutin