The fate of multiple-unit enteric-coated formulations in the stomach of the dog

Abstract

The gastrointestinal transit of enteric granules was studied in healthy dogs and in a dog suffering from pancreatic insufficiency by means of roentgenography. Coated granules of different sizes were given to the dogs during the main meal or with a small portion of food before the meal. The enteric materials used were hydroxypropyl methylcellulose phthalate (HPMCP) and cellulose acetate phthalate (CAP). The majority of enteric granules with a diameter of 0.3–1 mm and 1–1.7 mm remained in the stomach for up to 6–8 h. Reduction in granule size and the time of adding the drug to the food were shown to have no significant effect on the gastric emptying of these granules. The formulations were emptied from the stomach much later than food, and it is therefore highly questionable whether this particular dosage form is suitable for the treatment of pancreatic insufficiency in dogs. A special type of controlled-release granule was developed, using HPMCP as a coat (7%) and potato starch as a disintegrant in the core. This formulation disintegrated in front of the pylorus 1–2 h after drug administration, showing an almost ideal release of the drug suitable e.g. for pancreatic enzyme therapy. However, further development is necessary.