Bioavailability in human volunteers of three intramuscular formulations of cefonicid: a long-acting cephalosporin.

Three different intramuscular formulations of cefonicid (a new long acting cephalosporin) have been tested for bioavailability in 12 healthy volunteers, using a triple crossover design. No significant differences were detectable between the bioequivalence of the three formulations in terms of area-under-curve and 24-h urinary excretion. However, one of the formulations (A) was absorbed significantly more rapidly from the site of injection, causing higher serum levels for up to 1.5 h after administration. A significantly greater urinary excretion was also found up to 8 h after administration of formulation A. All three formulations were well tolerated, and no side-effects or significant changes in laboratory tests were observed.