| abstract |
Bioadhesive polymers in the form of, or as a coating on,nmicrocapsules containing drugs or bioactive substances whichnmay serve for therapeutic, or diagnostic purposes in diseasesnof the gastrointestinal tract, are described. The polymericnmicrospheres all have a bioadhesive force of at least 11nmN/cm 2 (110 N/m 2 ). Techniques for the fabrication ofnbioadhesive microspheres, as well as a method for measuringnbioadhesive forces between microspheres and selected segmentsnof the gastrointestinal tract in vitro are also described.nThe quantitative method provides a means to establish ancorrelation between the chemical nature, the surfacenmorphology and the dimensions of drug-loaded microspheres onnone hand and bioadhesive forces on the other, allowing thenscreening of the most promising materials from a relativelynlarge group of natural and synthetic polymers which, fromntheoretical consideration, should be used for makingnbioadhesive microspheres. |