Please activate JavaScript!
Please install Adobe Flash Player, click here for download
ePaper created 2017-03-14, 10:25:37 | version 1.49.03
HEALTH compressed air nozzle polymer solutions aspirator heating coil drying cylinder 1 10 μm 2 cyclone dry product outlet ilter FUNCTIONAL ENCAPSULATION OF ACTIVE INGREDIENTS BY MEANS OF SPRAY DRYING M i cha e l Wa lz , Achim We b e r For the production of encapsulated active ingredients in particles, we use, the one-step process of spray drying. A polymer solution in a drying cylinder is atomized into ine droplets by means of compressed gas. The hot gas stream serves to evaporate the solvent, and the resulting particles are separated (Fig. 2). A great advantage is that the application of spray drying does not require any further puriication. Encapsulation using the two-luid nozzle The optimal parameters for the spray drying process are determined using the design of experiment. The drying tem- perature, atomizing gas, pumping speed and the concentra- tion of the polymer solution are varied. Subsequently, various active ingredients are encapsulated, such as dexpanthenol for applications on the skin. For natural inulin, we have observed that the active ingredient is completely released within a few hours. A modiication of the biopolymer with acetic acid and propionic anhydride signiicantly improved the stability of the particles in aqueous solutions (Fig. 4). There was also a pro- longed release following the encapsulation of dexpanthenol with these modiied inulin derivatives. Encapsulation of active ingredients Due to several aspects, the encapsulation of active ingredients is of interest to the pharmaceutical and medical technology industry. On the one hand, capsules serve to protect the ac- tive ingredients from external inluences, for example, gastric juice resistance during oral administration. On the other hand, the treatment of patients can be improved by controlled release. Using a continuous release system leads to lower drug concentrations resulting to fewer side effects. Above all, how- ever, the use and safety of therapy is enhanced compared to conventional methods. An active substance depot can release the active substance over several days to months, avoiding the need for a regular tablet intake, which is considered a great advantage in our era of the aging population. Formulation by means of spray drying Various aspects such as stability, biocompatibility, cytotoxicity and release behavior must be considered in the formulation of such active ingredient systems. In collaboration with the Institute of Interfacial Engineering and Plasma Technology IGVP of the University of Stuttgart, Fraunhofer IGB is investi- gating the use of biopolymers from renewable raw materials as a matrix material for active ingredient formulations. As part of a project, inulin was used as a biopolymer in spraying process using a two-luid and three-luid nozzle (Fig. 3) for the encapsulation of active ingredients. Inulin was additionally chemically modiied in order to investigate the inluence on the release properties. 5 8