Relative bioavailability of commercial ampicillin formulations in man.

The relative bioavailability of three commercial ampicillin products was examined in 12 human subjects using a crossover experimental design. Based upon the areas under the ampicillin plasma concentration-time curves after the oral administration of 250 mg. ampicillin and using an analysis of variance technique no statistically significant differences were found between the products examined. These findings are in contrast to those of a recent report and appear to be explained by formulation differences. These relatively minor differences in formulation reflect the importance of formulation variables in providing efficient drug therapy. The intrasubject variation associated with several of these products is quite marked and is consistent with the incomplete and erratic absorption of this antibiotic in man.