Effect of ionic strength and pH of dissolution media on theophylline release from hypromellose matrix tablets-Apparatus USP III, simulated fasted and fed conditions

► Ionic concentration strength and pH on theophylline release evaluated using USP III. ► Ionic concentration strength varied over a range of 0-0.4 M to simulate the GI fed and fasted states. ► DSC hydration results explained the theophylline release from their HPMC matrices. ► Method can be useful in predicting potential ionic effects in fed and fasted states.