title: In vitro and in vivo evaluations of BMY-28100, a new oral cephalosporin.
abstract: A new semisynthetic oral cephalosporin, BMY-28100, was evaluated for in vitro and in vivo antibacterial activities in comparison with cefaclor and cephalexin. BMY-28100 showed in vitro activity 3- and 10-fold more potent than that of cefaclor against Staphylococcus aureus and Streptococcus pneumoniae, respectively. BMY-28100 was slightly better than cefaclor and about 4 times more active than cephalexin against Haemophilus influenzae and Neisseria gonorrhoeae. Escherichia coli, Klebsiella pneumoniae and Proteus mirabilis were comparably susceptible to BMY-28100 and cefaclor. The bactericidal activity of BMY-28100 against S. aureus, E. coli and P. mirabilis was equal to or twice as high as MIC value, which was similar to that of cefaclor. The stability of BMY-28100 against penicillinases was nearly comparable to that of cefaclor, whereas cefaclor was somewhat unstable to cephalosporinases. BMY-28100 was about twice as active as cefaclor against three Gram-positive bacterial infections. BMY-28100 was also more potent against infections of H. influenzae and P. mirabilis, but slightly less active against E. coli Juhl than cefaclor. Blood level parameters of BMY-28100 were significantly superior to those of cefaclor and slightly better than cephalexin in mice and rats. The urinary recovery of BMY-28100 was somewhat higher and comparable to that of cefaclor and cephalexin, respectively. BMY-28100 was more stable than cefaclor in human and calf sera at 37 degrees C.
mesh_terms: D000818:Animals; D001420:Bacteria, Aerobic / Q000187:drug effects; D001424:Bacterial Infections / Q000517:prevention & control; D002433:Cefaclor / Q000494:pharmacology; D002506:Cephalexin / Q000494:pharmacology; D002511:Cephalosporins / Q000493:pharmacokinetics / Q000494:pharmacology*; D051379:Mice; D008826:Microbial Sensitivity Tests; D051381:Rats; D001618:beta-Lactamases / Q000378:metabolism; D000097670:Cefprozil
chemical_list: D002433:Cefaclor; D002506:Cephalexin; D002511:Cephalosporins; D001618:beta-Lactamases; D000097670:Cefprozil