Gastric emptying of tablets and granules in humans, dogs, pigs, and stomach-emptying-controlled rabbits.

Rates of gastric emptying of nondigestible tablets and granules in humans were compared with those in three animal models: dogs, minipigs, and stomach-emptying-controlled rabbits. The rates of gastric emptying of both dosage forms in dogs tended to be faster than or similar to those in humans, whereas the rates in pigs were slower. In stomach-emptying-controlled rabbits, no tablets were emptied from the stomach because of their large size. The rate of gastric emptying of granules in rabbits was slow and variable. Food delayed gastric emptying in dogs, especially for tablets. In rabbits, the rate of gastric emptying of granules was faster when the granules were given before feeding, in comparison with that after feeding or under fasting conditions. We concluded that the dog is a better animal model for bioavailability studies under fasting conditions than the pig and the rabbit.