[Serum and tissue concentrations after a single dose of cefaclor]

Serum and tissue concentrations of cefaclor were determined a total of 155 and 96 times respectively in 16 volunteers after a single dose of 1 g. At this dosage peak concentrations of 13.5, 14.5 and 13.4 mcg/ml were measured after 60, 90 and 120 minutes respectively. Tissues in which concentrations were measured included cortical bone, spongy bone, muscle, fascia, cutis and subcutis. By measuring blood concentrations of the tissue samples, a division could be made for purposes of calculation into intravascular and extravascular active components. Low amounts of extravascular cefaclor could be established merely in the fascia and in the cutis. The cefaclor concentrations found in spongy bone, muscles and subcutis proved to be determined to a large extent by the intravascular antibiotic. No cefaclor could be detected in cortical bone at the given dosage.