Floating dosage forms: an in vivo study demonstrating prolonged gastric retention

Floating Properties and Release Characteristics of Hollow Microspheres of Acyclovir

“…One attempt to overcome this problem is to extend the GI transit time of devices, by using floating dosage forms that have specific density lower than that of gastric fluids (1.004 g/cm 3 ) and remain buoyant in the stomach contents. The various buoyant preparations include hollow microspheres (microballoons), granules, powders, capsules, tablets (pills), and laminated films (Deshpande et al 1996(Deshpande et al , 1997Chien, 1997;Whiteheas et al 1998;Dressman 2000;Singh and Kim 2000).…”

“…As a result, it may cause high variability in bioavailability. In contrast, a multipleunit floating system, which distributes widely throughout the GI tract, provides a longer lasting and more reliable release of drugs (Deshpande et al 1996(Deshpande et al , 1997Whiteheas et al 1998;Singh and Kim 2000).…”

Formulation and Evaluation of Gastroretentive Floating Bioadhesive Tablets of Hydrochlorthiazide

“…Higuchi described the release of drugs from insoluble matrix as a square root of time dependent process based on Fickian diffusion equation 3. The Hixson-Crowell cube root law equation 4 describes the release from systems where there is a change in surface area and diameter of particles or tablets [13][14][15][16][17].…”

Development and evaluation of floating microspheres of verapamil hydrochloride

“…Various attempts have been made to prolong the retention time of the dosage form in the stomach. One such method is the preparation of a device that remains buoyant in the stomach contents due to its lower density than that of the gastric fluids (Desai, Bolton, 1993;Whitehead et al, 1998). Single-unit formulations are associated with problems such as sticking together or being obstructed in the gastrointestinal tract, which may have a potential danger of producing irritation.…”