IN-VITRO CHARACTERIZATION OF GASTRORETENTIVE MICROBALLOONS PREPARED BY THE EMULSION SOLVENT DIFFUSION METHOD

Microballoons floatable on JPXIII No.1 solution were developed as a dosage formcapable of floating in the stomach. Microballoons were prepared by the emulsion solventdiffusion method using enteric acrylic and other polymers with drug in a mixture ofdichloromethane and ethanol. It was found that preparation temperature determined theformation of cavity inside the microsphere and the surface smoothness, determining thefloatability and the drug release rate of the microballoons. The correlation between thebuoyancy of microballoons and their physical properties, e.g. apparent density androundness of microballoons were elucidated. The drug loading efficiency ofmicroballoons was also determined. The optimum loading amount of metformin in themicroballoons was found to impart ideal floatable properties to the microballoons. Byfitting the data into zero order, first order and Highuchi model it was concluded that therelease followed zero order release.