The pharmacokinetics of carboplatin were investigated in cancer patients after single, IV infusion doses of 75, 150, 247.5, 300, 375, and 450 mg/m2. Total plasma and urine platinum and plasma ultrafilterable platinum concentrations were determined by atomic absorption spectrometry. Carboplatin was analyzed in plasma by a specific high-performance liquid chromatography (HPLC) procedure. Total plasma platinum, which represented free carboplatin, protein-bound platinum and metabolites, declined triexponentially; plasma half-lives (t1/2 lambda 1, 0.2 to 0.4 hr; t1/2 lambda 2, 1.3 to 1.7 hr; t1/2 lambda 3, 22 to 40 hr) and total body clearance (CLTB 2.8 +/- 0.5 L/m2/hr) were dose independent. Maximum plasma concentrations (Cmax) and area under the plasma concentration time curve (AUC) increased proportionally with dose. Plasma ultrafilterable platinum and carboplatin concentrations at doses of 375 and 450 mg/m2 declined in a biphasic manner. Plasma carboplatin elimination (t1/2 lambda 1, 0.50 hr; t1/2 lambda 2, 2.2 hr) and CLTB (4.4 to 5.6 L/m2/hr) were also independent of dose; AUC and Cmax increased proportionally to dose. Plasma free platinum was essentially all carboplatin for 8 or 12 hours after administration. Carboplatin did not bind to plasma protein in vitro but did degrade (t1/2-26 hours) to yield a reactive intermediate that bound rapidly and irreversibly to protein. The long terminal elimination half-life of plasma platinum was associated with irreversible binding of a platinum metabonate to plasma protein. The urinary excretion of platinum (0 to 24 hours) accounted for 58 to 72% of doses in 12 to 24 hours. The remainder of the dose is slowly excreted. The pharmacokinetics, in vivo stability, protein binding, and elimination of carboplatin are distinct from the first-generation analog cisplatin.

A selective detection method for biogenic amines present in highly complex matrixes was devised by employing both electrokinetic injection and on-column-derivatization capillary electrochromatographic methods. The on-column derivatization capillary electrochromatography system was evaluated by use of a capillary column (total length of 45 cm, effective length of 25 cm) fabricated using a 100-mcirom (i.d.) fused-silica capillary tube packed with 5-microm (i.d.) ODS particles that were tolerant of an alkaline environment. The column was filled with a run buffer consisting of a derivatization reagent, o-phthalaldehyde/2-mercaptoethanol, in a mixture of borate buffer (pH 10). After electrokinetic injection of a mixture of five biogenic amines (histamine, serotonin, tyramine, putrescine, cadaverine) as a test sample, the free amines entered into the anodic site of the capillary column and started to travel along the column, during which time the analytes reacted with the derivatization reagent, separated out, and were detected with an absorbance at 340 nm when high voltage was applied to the column. When this system was applied to a mixture containing 5 biogenic amines and 17 amino acids, the 5 biogenic amines plus arginine selectively entered into the capillary with the electrokinetic injection and were observed on the electrochromatogram, but none of the amino acids lacking arginine were detected. The designated method was also tested for its ability to determine the presence of biogenic amines in the crude extracts obtained from two types of aged fish.

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