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.