Telithromycin (TEL), an oral ketolide antibiotic, is currently available as a 300 mg tablet. To facilitate administration, a reduced-size tablet, about 75% of the currently available formulation in volume, was developed. As part of this development, we conducted dissolution and bioequivalence studies in human subjects to evaluate formulation bioequivalence. In the dissolution study, an average exceeding 85% of both currently available and reduced-size tablets dissolved in all test solutions within 15 min. Since results met criteria in bioequivalence study guidelines, dissolution profiles for both formulations were determined to be equivalent In the bioequivalence study where a single dose of 600 mg was administered to 36 male and female subjects, mean ratios between reduced-size and currently available tablets for the maximum plasma concentration (Cmax) was 94.2% and the area-under-plasma-concentration-time curve (AUC0-z) was 97.0%. The two-sided 90% confidence interval was 80-125%, within the bioequivalence acceptance limit. The two formulations were therefore determined to be equivalent Overall results thus indicate that TEL reduced-size and currently available tablet formulations were biol. equivalent