Dissolution behaviors of theophylline sustained-release preparation.

The dissolution patterns of 2 kinds (A and B) of sustained-release preparations of the ophylline were measured with the J. P. dissolution tester in the first fluid and the second fluid of the J. P. disintegration test. In addition, the dissolution pattern of tablet half on breaking of scored tablet of sample B was measured in the second fluid. The following results were obtained.1) In sample A, the times required for 50% dissolution in the first fluid and in the second fluid were about 8 hours and 10 hours, respectively.2) In sample B, the times required for 50% dissolution in the first fluid and in the second fluid were about 7 hours and 4 hours, respectively.The dissolution patterns of both samples were linear. As the dissolution patterns of tablet half, the time required for 100%dissolution was about 10 hours.