Bioavailability of clarithromycin cyclodextrin ternary complexes upon oral administration to healthy beagle dogs

The dissolution profiles of clarithromycin (CLM) and its beta-cyclodextrin-citric acid ternary complexes (CTC) were examined. CTC showed an enhanced dissolution rate in pH 6.8 phosphate buffers. The relative bioavailability was evaluated by comparing area under the plasma concentration-time curve (AUC) of the pure CLM with that of its cyclodextrin-citric acid ternary complexes those were filled into hard gelatin capsules. To compare the pharmacokinetic behavior, both plasma levels of parent compound and the active metabolite 14-OH-CLM concentrations were estimated. The relative bioavailability value as the ratios of CLM of mean total AUC for CTC relative to CLM was 120.3%. The relative bioavailability value as the ratios of 14-OH CLM of mean total AUC for CTC relative to CLM was 95.3%. The results suggest that the absorption of CTC in beagle dogs was slightly improved because of the enhanced dissolution rate of CTC at pH 6.8.