Permeability and Stability of Microcapsules
Microcapsules consisting of natural polysaccharide hydrogels such as pectinates have a large potential for the transportation of liquid drugs with food. If a controlled and site specific release of the encapsulated drugs is desired, they must be stored sufficiently long under different environmental conditions. Here, we optimize the capsules with respect to the retention time of the encapsulated drugs and the chemical stability under gastrointestinal conditions. To achieve this, we coat the pure hydrogel capsules with the natural resin shellac. NMR microscopy is used for the characterization of the structure and suitability of these microcapsules. We measure the permeability of differently prepared capsules by using paramagnetic probe molecules. By an acquisition of T