A rapid gas-liquid chromatographic determination of antipyrine clearance in the rat.

The assay procedure described in this paper allows the calculation of pharmacokinetic data of antipyrine disposition to be obtained from a single animal with minimal disturbance in hematocrit. A sample volume (100 microliters) allows the repeated use of the same rat for studies of hepatic drug metabolism. The lower limit of sensitivity is 5 micrograms/ml, with a range of linearity extending to 100 micrograms/ml. This allows for various dosing regimens. The GLC assay is rapid and accurate as shown by comparison with previously published values for the half-life of antipyrine in rats.