High-performance liquid chromatographic analysis of baclofen in plasma and urine of man after precolumn extraction and derivatization with o-phthaldialdehyde.

A reversed-phase high-performance liquid chromatographic method for the determination of the skeletal muscle relaxant baclofen in human plasma and urine is described. Cation-exchange extraction, precolumn derivatization with o-phthaldialdehyde, and on-column concentration precede fluorimetric detection (excitation at 340 nm, emission at 460 nm). The precision of the assay was always better than 6%. Recoveries of standards added to plasma and urine were 92% and 93%, respectively. With a sample size of 0.5 ml, a detection limit of a few nanograms, and the possibility of analysing up to four samples per hour, this method is suitable for pharmacokinetic studies. An example is presented.

Rapid quantitative determination of seven anthracyclines and their hydroxy metabolites in body fluids.

A reversed-phase high-performance liquid chromatographic method is described for the determination of seven anthracycline analogues and their hydroxy metabolites. The method is suitable for analysis of 30 plasma samples a day. The detection limit is 0.5 ng/ml for all compounds. Examples of the pharmacokinetics of adriamycin and carminomycin in man are shown.

Pharmacokinetics of anthracyclines in dogs: evidence for structure-related body distribution and reduction to their hydroxy metabolites.

The pharmacokinetic disposition of the anthracyclines, adriamycin (doxorubicin), daunorubicin, 4'-epi-adriamycin, carminomycin, and 4-demethoxy-daunorubicin, and the formation of their reduced C13 hydroxy metabolites were studied in dogs. The presence of a C14hydroxy group (adriamycin and 4'epi-adriamycin) drastically reduces the appearance of the C13 hydroxy metabolites in plasma. Substitution of the C4-H with C4-OH and C4-OCH3, in this rank order, decreases the area under the plasma concentration-time curves of the parent compounds and their C13 hydroxy metabolites.