A competitive protein binding assay for allopurinol and oxipurinol

✍ Scribed by Kenneth R. Hande; Bruce A. Chabner

• Publisher: Elsevier Science
• Year: 1980
• Tongue: English
• Weight: 604 KB
• Volume: 101
• Category: Article
• ISSN: 0003-2697
• DOI: 10.1016/0003-2697(80)90035-4

✦ Synopsis

A competitive protein binding assay for allopurinol or oxipurinol has been developed based on the tight binding of these drugs to reduced xanthine oxidase. Free drug is separated from that bound to xanthine oxidase by absorption with dextran-albumin coated charcoal. This assay can detect as little as 0.1 pM ahopurinol or oxipurinol in water, serum, plasma, or urine. Competitive analogs such as hypoxanthine, xanthine, and uric acid require concentrations IOO-to lOOO-fold greater than those of allopurinol or oxipurinol to cause significant interference with the assay. This assay is simple and rapid with the ability to assay 20-30 samples within 2 h. Measurement of oxipurinol levels in clinical samples shows good correlation with published results using more complex analytical techniques.