ABSTRACT
A number of 7-(arylacetamido)-3-substituted cephalosporins were prepared and tested in animals for oral absorbability. Bioavailability in mice, rats, dogs, and monkeys was determined after oral or parenteral administration. Oral bioavailability of five compounds selected for more intensive study was generally higher than that of penicillin V in all species tested. The results of ED50 testing against experimental infections in mice generally supported the bioavailability studies. Antibiotic activities were evaluated against Gram-positive and Gram-negative organisms with some derivatives expressing in vitro activity similar to cefaclor. The plasma half-life in rats was relatively short and the plasma curves were strongly influenced by probenecid, indicating rapid renal secretion. Some 7-(arylacetamido)-3-chloro cephalosporins are orally absorbed in animals to a greater extent than penicillin V, and antibacterial agent of proven clinical utility.
Subject(s)
Cephalosporins/pharmacokinetics , Administration, Oral , Animals , Biological Availability , Cephalosporins/blood , Cephalosporins/chemical synthesis , Dogs , Macaca mulatta , Male , Mice , Microbial Sensitivity Tests , Rats , Rats, Inbred StrainsABSTRACT
The structure-activity relationship for 7-arylacetamido cephalosporins has been extended. Modifications of the 7-aryl group led to improvements in microbiological activity against Gram-positive organisms. However, Gram-negative activity was generally much poorer than that of the lead compound 7-[(2-aminothiazol-4-yl)acetamido]-3-chloro-cephalosporanic acid (A). Modifications of the 3-position did not significantly change the microbiological activity or spectrum. Of the compounds selected for mouse protection studies (ED50's), 7-[(benzothien-3-yl)acetamido]-3-chloro cephalosporin and A showed the best per oral to subcutaneous ED50 ratios.
Subject(s)
Cephalosporins/pharmacokinetics , Administration, Oral , Animals , Bacterial Infections/drug therapy , Bacterial Infections/microbiology , Biological Availability , Cephalosporins/blood , Cephalosporins/therapeutic use , Gram-Negative Bacteria/drug effects , Gram-Positive Bacteria/drug effects , Mice , Microbial Sensitivity Tests , Structure-Activity RelationshipABSTRACT
A series of 7 alpha-methoxy-7 beta-amido-3-chloro-3-cephem-4-carboxylic acids was prepared and evaluated for biological activity. When compared with the parent 7-non-methoxy analogues, these new 7 alpha-methoxy-3-chloro cephalosporins displayed diminished antimicrobial activity.
