Determination of 6,4'-bis-(2-imidazolinylhydrazone)-2-phenylimidazo[1,2-a]py ridine in plasma and whole blood by high-performance liquid chromatography

A selective and sensitive HPLC assay for the quantitative determination of a new antifilarial drug, 6,4'-bis-(2-imidazolinylhydrazone)-2-phenylimidazo[1,2-a]pyr idine (CDR 101) is described. After extraction from plasma and blood, CDR 101 was analysed using a C18 Nucleosil ODS column (250x4.6 mm, 5 microm particle size) and mobile phase of acetonitrile-0.05 M ammonium acetate adjusted to pH 3.0, with UV detection at 318 nm. The mean recoveries of CDR 101 in plasma and blood over a concentration range of 25-500 ng/ml were 95.5+/-2.01% and 83.3+/-1.87%, respectively. The within-day and day-to-day coefficient of variations for plasma were 3.23-6.21% and 2.59-9.90%, respectively, those for blood were 2.59-5.92% and 2.89-6.82%, respectively. The minimum detectable concentration for CDR 101 was 1 ng/ml in plasma and 2.5 ng/ml in whole blood. This method was found to be suitable for clinical pharmacokinetic studies.