[The solubility kinetics of enteric-resistant tablets using riboflavin test tablets. 6. Pharmaceutic-technologic and analytic studies on gastric juice-resistant dosage forms].

To examine the dissolution kinetics of enteric coatings in vivo a test system with riboflavine was developed. This system allows to realize the beginning of disintegration in the small gut because riboflavine is excreted in urine already within 1 h after ingestion, and to locate the area of dissolution of the tablet in vivo, because riboflavine absorption is reduced in the great gut and colon. Thus the test system allows to examine and improve coating compositions in vivo and to demonstrate changes of drug dissolution in vivo conditioned by storage of enteric coated pharmaceuticals.