HIGH-PERFORMANCE LIQUID-CHROMATOGRAPHIC DETERMINATION OF CGA-184699 (LUFENURON) IN DOG AND CAT-BLOOD

A method for quantitation of lufenuron (CGA-184699) in blood was devel oped for the purpose of determining lufenuron pharmacokinetics in cats and dogs. Lufenuron is an investigational insect development inhibito r used in the control of fleas on cats and dogs. An extract of lufenur on from blood is passed through a solid-phase extraction column before injection onto a C-18 column and elution with a mobile phase of aceto nitrile and tetrahydrofuran in water. The eluate is monitored with a U V detector at 254 nm. Extraction efficiencies of lufenuron and the int ernal standard (CGA-112913) were 96% and 94%, respectively. The minimu m detectable amount was 0.1 ng; day-to-day variation showed a CV% of l ess than 5%. Application of the method to a pharmacokinetic study in w hich one cat and dog received a single intravenous 10 mg/kg dose showe d half-lives of approximately 60 days in both species.