Influence of feeding on the bioavailability of ronidazole prolonged-release formulations in pigeons

The influence of feeding on the bioavailability of ronidazole (5 mg per animal) formulated as a hydrophilic-matrix tablet or as lipophilic pellets, was evaluated in pigeons. Administered to fed pigeons, prolonged drug absorption was obtained for both formulations. In non-fed pigeons an immediate grinding of the formulations in the gizzard resulted in rapid drug absorption. This indicates that prolonged residence of the prolonged-release formulations in the crop obtained in the fed condition seemed the only possible means of obtaining prolonged drug release in pigeons.