Vanillin release from macrocapsules

Encapsulation, which is the base of controlled release methodology, offers several advantages over conventional applications of drugs and fragrances. Phase inversion precipitation is an economical and simple way to prepare capsules with diverse sizes and morphologies. Here, we report on the preparation of various polysulfone capsules containing different vanillin concentrations. Polymeric capsules of ca. 3 mm diameter have been obtained employing di-methylformamide (DMF)/water as solvent/non-solvent pair. Capsule structure has been characterized by scanning electron microscopy (SEM). The capsules obtained show similar morphologies. They have a highly porous structure and the polymer matrix is present through all the capsule volume. Vanillin release from the capsules has been monitored along with time. High performance liquid chromatography (HPLC) has been used as analytical technique to determine vanillin concentration. The release of vanillin is found to be fast during the first 10 hours of experiments and then it experiences an slower release period to finally reach a plateau. The maximum encapsulation capacity of polysulfone capsules has been attained, and it is reached when polymer to vanillin ratio, in the polymeric solution is 3/2.