Floating drug delivery is associated with certain limitations. Drugs that irritate the mucosa, those that have multiple absorption sites in the gastrointestinal tract, and those that are not stable at gastric pH are not suitable candidates to be formulated as floating dosage forms. To overcome this limitation, a bioadhesive polymer can be used to coat the dosage so that it adheres to gastric mucosa, or the dosage form can be administered with a full glass of water to provide the initial fluid for buoyancy. Single unit floating capsules or tablets are associated with an “all or none concept,” but this can be overcome by formulating multiple unit systems like floating microspheres or microballoons. The aim of this article is to review the physiological and anatomical factors and methods for preparing floating microspheres, which plays an important role in design of floating drug delivery systems.
Loading....