title: Distribution in normal and inflammatory tissue of a new semisynthetic cephalosporin, SK&F 75073.
abstract: SK&F 75073 is a new cephalosporin with broad spectrum antibacterial activity. SK&F 75073-14C and cefazolin-35S were administered separately to groups of rats as a single intramuscular dose of 20 mg/kg. Tissues with highest drug levels 15 minutes following dose were as follows: (SK&F 75073/cefazolin levels), kidney - 86/70 microgram/g, liver - 33/22 microgram/g, lung - 29/17 microgram/g, heart - 23/10 microgram/g, adrenal - 13/7 microgram/g. Plasma levels at peak were 134 microgram SK&F 75073/ml (half-life, 1.9 hours) and 72 microgram cefazolin/ml (half-life, 0.75 hours). Dose excreted in 24 hours was: SK&F 75073, urine 66% and feces 27%; cefazolin, urine 96% and feces 2%. Both antibiotics were also administered, at 20 mg/kg, to rats with the carrageenan-induced inflammatory pouches. Exudate from these pouches contained from 2 to 10 times more SK&F 75073 than cefazolin. Radioassay and bioassay of these substances in the exudate gave similar results. Serum protein binding ranged from 96 approximately 98% for SK&F 75073 and 34 approximately 69% for cefazolin. Data indicated that highly protein bound SK&F 75073 enters tissues and tissue fluid to a greater extent than the lesser bound but therapeutically proven antibiotic agent cefazolin.
mesh_terms: D000818:Animals; D001798:Blood Proteins / Q000378:metabolism; D002437:Cefazolin / Q000097:blood / Q000378:metabolism / Q000652:urine; D002511:Cephalosporins / Q000097:blood / Q000378:metabolism* / Q000652:urine; D005122:Exudates and Transudates / Q000378:metabolism; D005243:Feces / Q000032:analysis; D007249:Inflammation / Q000378:metabolism*; D008297:Male; D011485:Protein Binding; D051381:Rats; D014018:Tissue Distribution
chemical_list: D001798:Blood Proteins; D002511:Cephalosporins; D002437:Cefazolin