Background: The general purpose of this review was to briefly describe the Gastro-Retentive
Drug Delivery System (GRDDS) and to primarily focus on mechanisms of flotation for gastric retention.
Methods: The principle mechanism of Floating Drug Delivery Systems (FDDS) is mainly based on
hydro-dynamically controlled low-density system, which gets swollen when comes in contact with the
gastric environment and remains buoyant for an extended period of time with improved bioavailability
and therapeutic efficacy. The main perspective of this review was to focus on microbubble drug delivery
due to its wide range of applications.
Results: Microbubble is a new, economically viable, and non-invasive technique that is alternative to
conventional techniques. The size of microbubbles ranges from 1-100 micrometers, which contain oxygen
or air and remain suspended for prolonged drug release. Due to its great potential, microbubble is
used in the therapeutic delivery of drug molecules or genetic material at their specific targeted site in
various diseases. The recent research also suggests that ultrasound-mediated microbubble is more frequently
used in the biomedical field for imaging of site-specific molecule targeting for the detection of
disease and site-specific drug delivery.
Conclusion: Gastro-retentive floating drug delivery system was considered as the most favorable approach
for site-specific drug delivery. But nowadays, microbubble is gaining more popularity for its
potential applications in the biomedical field. In recent years, there is much progress in microbubble
for site-specific delivery of a drug or genetic material. Recent research also suggests that the ultrasound-
mediated microbubble has shown a positive impact on the diagnosis and clinical management of
various diseases such as liver cirrhosis, brain tumor, ocular, and urinary tract infection.