Determination of ribavirin in human serum and plasma by capillary electrophoresis.
The electrophoretic separation of ribavirin and 5-methylcytidine (internal standard) by capillary electrophoresis was examined. Separation was achieved using reverse polarity in a 100 mM borate electrolyte, pH 9.1, with 5 mM spermine added to reduce the electroosmotic flow. Sample preparation based on acetonitrile protein precipitation was found to be unsuitable for ribavirin analysis in patient samples due to insufficient sensitivity and interferences. Solid-phase extraction employing phenyl boronic acid cartridges provided cleaner separations. Using this approach with 500 microL sample and reconstitution of the dried extract into 100 microL of 33% v/v 100 mM phosphate buffer, pH 6.4 / 67% v/v acetonitrile, the detection and quantitation limits were determined to be 0.05 and 0.10 microg/mL, respectively, a sensitivity that is suitable for therapeutic drug monitoring of ribavirin in human plasma and serum samples. The method was validated and compared to a high-performance liquid chromatography (HPLC) method, showing excellent agreement between the two for a set of samples that stemmed from patients being treated with ribavirin and interferon-alpha-2b for a hepatitis C virus infection.
Breadmore
Michael C
MC
Department of Clinical Pharmacology, University of Bern, Murtenstrasse 35, CH-3010 Bern, Switzerland.
Theurillat
Regula
R
Thormann
Wolfgang
W
D000097:Acetonitriles / Q000737:chemistry; D002851:Chromatography, High Pressure Liquid; D003562:Cytidine / Q000031:analogs & derivatives* / Q000032:analysis* / Q000097:blood; D019075:Electrophoresis, Capillary / Q000379:methods*; D019698:Hepatitis C, Chronic / Q000188:drug therapy / Q000378:metabolism; D006801:Humans; D000077190:Interferon alpha-2; D016898:Interferon-alpha / Q000494:pharmacology*; D011994:Recombinant Proteins; D012254:Ribavirin / Q000032:analysis* / Q000097:blood / Q000494:pharmacology
D000097:Acetonitriles; D000077190:Interferon alpha-2; D016898:Interferon-alpha; D011994:Recombinant Proteins; D012254:Ribavirin; D003562:Cytidine; C016568:5-methylcytidine; C032159:acetonitrile