Analysis of cyclazocine in plasma.

ABSTRACT

The analysis of plasma cyclazocine by two methods is described. The radioimmunoassay employed a 125I-labeled radioligand, rabbit antiserum, and sepration of bound from free cyclazocine with a second antibody. The radioimmunoassay was specific for cyclazocine and had a detection limit of approximately 20 pg/ml. The GLC method employed a mass spectrometer as the detector and had a detection limit of approximately 109 pg/ml. Both techniques had acceptable accuracy and precision when used to quantitate cyclazocine in dog and human plasma. The methods were used successfully to quantitate cyclazocine from beagle hounds receiving 0.5 mg of 3H-cylazocine/kg iv. The decline in plasma cyclazocine fitted a two-compartment body model with a mean plasma clearance rate of 39.2 liters/hr.