A New Parenteral Cephalosporin. SK&F 59962: in Vitro and in Vivo Antibacterial Activity and Serum Levels in Experimental Animals

SK&F 59962, a new parenteral cephalosporin was found to have a high order of in vitro and in vivo antibacterial activity against a broad-spectrum of clinical isolates. When tested in vitro against gram-negative organisms, SK&F 59962 was consistently more active than cefazolin and far superior to cephalothin. This new antibiotic had activity equal to that of cephalothin against gram-positive bacteria. Enterobacter species were found to be susceptible to SK&F 59962. In mouse infection studies using bacterial pathogens, SK&F 59962 had protective activity of the order of that of cefazolin and superior to that of cephalothin. Following parenteral administration the serum profile of SK&F 59962 in the mouse, dog and squirrel monkey was similar to that of cephalothin. SK&F 59962 and cephalothin had lower peak serum concentrations and shorter biologic half-lives than those of cefazolin.