An Enteric Compression Coating II : In Vivo Studies With Barium Sulfate-Potassium Iodide and Barium Sulfate Tablets

Barium sulfate and barium sulfate-potassium iodide tablets with special characteristics were prepared to test a new enteric compression coating. The location and passage of these tablets into the gastrointestinal tract was controlled by the position of patients or by the attachment of strings to the tablets. Dissolution of the coating and core was demonstrated in vivo by X-ray, by the saliva iodide test, and by recovery of the tablets. The coating was found to resist gastric fluid and to dissolve rapidly in intestinal fluid by both the in vitro and the in vivo testing methods. The rate of absorption of iodide was influenced by the position of the patients.