Simple method for determination of the cephalosporin DQ-2556 in biological fluids by high-performance liquid chromatography

Phase I study of DQ-2556, a new parenteral 3-quaternary ammonium cephalosporin antibiotic

The safety and pharmacokinetic properties of DQ-2556, a new parenteral cephalosporin, were evaluated using healthy volunteers after 5-minute intravenous infusion of doses of 250, 500, 1000, or 2000 mg and a 1-hour infusion of 2000 mg, and an intramuscular dose of 500 mg. The half-lives of DQ-2556 ranged from 1.64 to 2.15 hours. The peak serum concentrations and area under the curve values were linearly correlated to the doses. The mean urinary recoveries were 80.0 to 85.5% of a dose within 24 hours. Salivary concentrations of the drug were low. There was no accumulation of DQ-2556 after 9 administrations every 12 hours. DQ-2556 was well tolerated.

Metabolic disposition of DQ-2556, a new cephalosporin, in rats, rabbits, dogs, and monkeys

The metabolic disposition of DQ-2556 was studied in rats, rabbits, dogs, and monkeys after an intravenous administration of 20 mg of 14C-labeled drug per kg of body weight. The serum data were analyzed by the two-compartment open model. The mean half-lives for the drug in serum at excretion phase were 18.1, 54.4, 21.8, and 63.6 min in rats, rabbits, dogs, and monkeys, respectively. The volume of distribution and total body clearance ranged from 0.18 to 0.30 liter/kg and 0.065 to 0.45 liter/h/kg, respectively. This compound was distributed to the tissues rapidly and well, especially to the kidney, trachea, liver, thyroid, skin, and lung. Tissue concentrations declined rapidly in a few hours and then very slowly. However, no accumulation was observed in any tissues. The results of a protein-binding study by ultracentrifugation indicated that DQ-2556 was 20 to 30% bound to serum proteins in animals and its affinity was low. Almost 90% of the administered radioactivity was excreted into urine in all species. Biliary excretion in rats was 3.1% of the dose. Nearly 70% of the dose or more was excreted into urine as unchanged drug, and the amounts of urinary metabolites were small except in rabbits, in which substantial amounts of polar metabolites were detected.