In a three-way cross-over study the bioavailability of cefuroxime was determined in 12 healthy volunteers after oral administration of 250 mg as cefuroxime axetil (Elobact; CAS 64544-07-6) in a plain aqueous suspension and as tablets from different batches. The tablet formulations showed nearly identical pharmacokinetic parameters and were bioequivalent. The mean maximum serum concentration was 4.7 micrograms/ml, achieved after 2.1 h. The serum half-live was 1.2-1.4 h, the area under the serum concentration-time curve was 14.3-14.4 micrograms/ml.h and the urinary recovery of unchanged cefuroxime was 54%. The bioavailability of cefuroxime after administration of cefuroxime axetil in aqueous suspension was lower, but bio-inequivalence was not demonstrated.