Microballoons as a Gastro-retentive Floating Drug Delivery System: An Overview

The recent developments in floating drug delivery systems (FDDS) includes the uniform distribution of multiple unit dosage forms along the GIT that could result in more reproducible drug absorption and reduced risk of local irritation; this gave birth to oral controlled drug delivery and led to development of Gastro-retentive floating microspheres. Microballoons (MB), a multiple unit dosage forms possessing a spherical cavity enclosed within a hard polymer shell have been develops as a dosage form characterize by excellent buoyancy in the stomach. This gastrointestinal transit-controlled preparation is design to float on surface of gastric juice, which has a specific gravity less than 1. Microballoons, loaded with drug in their outer polymer shells, prepare by the emulsion solvent diffusion method using enteric acrylic polymers; dissolve in a mixture of dichloromethane and ethanol. Dichloromethane evaporation appears to be especially related to cavity formation in microspheres. Microballoons incorporating a drug dispersed or dissolved throughout particle matrix have the potential for controlled release of drugs and floats continuously over the surface of acidic dissolution media containing surfactant for > 12 h in vitro. As the microballoons floats over the gastric contents, the drug is released slowly at the desired rate, which results in increased gastro-retention time and reduces fluctuation in plasma drug concentration.