Determination of the disappearance rate of azathioprine from circulating rat blood by high-pressure liquid chromatography.

ABSTRACT

A rapid and specific method of high-pressure liquid chromatography for determining 6-(1-methyl-4-nitro-5-imidazole) mercaptopurine (azathioprine) in the blood was developed using mu Bondapak C18 as adsorbent and 30% aquous methanol as eluent. Azathioprine was completely separated from related compounds in blood. The standard curve showed a linear relationship at least between 0.6 and 30 micrograms per ml of serum. Recovery was satisfactory and the analytical time needed was less than 20 min. Disappearance rates of azathioprine from circulating blood in rats were 0.026 in probenecid-treated rats, and 0.103 in intact rats.