Aminophylline bioadhesive tablets attempted by wet granulation

The bioadhesive systems are new delivery systems used to reduce bioavailability problems resulting from a too short stay of the pharmaceutical form at the activity or resorption site. Aminophylline bioadhesive tablets were made by wet granulation with different polymers: Carbomers 934 P, 974 P, EX 55, sodium carmellose, hypromellose and hydroxypropyl cellulose (HPC). Wet granulation is a limiting factor for bioadhesion. The combination of polyacrylic acids with hypromellose or sodium carmellose increases bioadhesion and decreases drug release. Carbomer 974 P alone had a lower adhesion than Carbomer 934 P. Combinations Carbomer 934 P/hypromellose 100 gave the best adhesion properties and a slow release dissolution.