BRL 20330, an oral prodrug of temocillin: bioavailability studies in man.

BRL 20330 is the o-methyl phenyl ester of temocillin which is well absorbed after oral administration and converted to temocillin in the body. BRL 20330 was administered to healthy subjects in a three-part cross-over study with single doses equivalent to 400, 600 and 800 mg of temocillin. Peak serum concentrations of temocillin were 9.8, 12.8 and 15.8 mg/l respectively and concentrations of 3.0-6.0 mg/l were measured at 12 h after dosing. High and prolonged concentrations of temocillin were measured in the urine. The mean urinary recovery was 22-25% and only 0.2% of unhydrolyzed BRL 20330 was detected in the urine. Little difference in the extent of absorption was noted when BRL 20330 was administered with food although the peak levels of temocillin were delayed and reduced slightly. Urinary concentrations of temocillin, even after 24 h, were bactericidal for a number of Gram-negative bacteria including multi-resistant strains. BRL 20330 was well tolerated and there was no evidence of gastro-intestinal adverse effects.