Drug delivery to the upper small intestine window using gastroretentive technologies

The bioavailability of drugs with an absorption window in the upper small intestine is generally limited with conventional pharmaceutical dosage forms. The residence time of such systems and, thus, of their drug release into the stomach and upper intestine is often short. To overcome this restriction and to increase the bioavailability of these drugs, controlled drug delivery systems with a prolonged residence time in the stomach can be used. Approaches to achieving prolonged residence times of the devices in the upper part of the gastrointestinal tract include the use of bioadhesive, size-increasing, and floating drug delivery systems.