Processing of microstructured solid particles based on simple or multiple emulsions by prilling - under consideration of their function preservation for encapsulation of functional components and controlled release

功能性组分（FC）的封装对于制药、食品、化妆品、精细化学品以及建筑和包装材料等工业领域的新产品开发具有广泛的意义。已批准了用于在乳液体系中明确包封功能组分的特别合适的结构。如果这样的乳液可以被稳定化，则包封的FC可以在储存和进一步加工条件下被保护/保存，以及可以应用控制释放。通过固化可以最好地实现复杂结构乳液的可靠稳定。因此，为了在进一步的生产、消费者应用或储存中获得乳液体系的最佳稳定性和处理性能，期望将此类乳液制成粉末形式。喷雾技术加上冷固化的喷雾滴（造粒）是我们的首选。在非常成功的第一个项目步骤（1-4年级）关于（i）两相喷嘴的几何设计参数，（ii）造粒工艺参数（喷雾压力，喷雾/造粒温度，体积流速，体积流速比（流体/气体））和（iii）喷雾液滴和造粒粉末系统的所得结构特性（液滴/颗粒尺寸和形状分布、相形态和结构保持）。基于实验和CFD模拟的研究提供了关于喷雾薄层破碎和喷雾液滴尺寸/液滴形态发展的动力学的进一步细节，同时考虑到非牛顿流变学和结构乳液特性。通过“后处理”步骤，即体外胃崩解搅拌反应器，对我们的造粒过程进行补充，使我们能够以定量方式研究功能化合物的丸粒-颗粒崩解和偶联释放动力学测量。在新的项目步骤（是5，6）的知识将进一步发展在两个主要方向：（1）开发一种新的喷雾斗争的概念，它叠加的压力和离心加速度场，从而提供了一个明确的喷雾丝分裂的可能性在瑞利域。因此，应在瑞利断裂进行之前强制大的长丝伸长，并通过实验和CFD模拟进行研究。这将允许以机械方式温和地流体处理喷雾颗粒，并且另外减小喷雾液滴/颗粒尺寸分布的宽度。这进一步导致（a）大大改善了封装的功能组分的保存，（B）更好的可调节的控制释放和（c）改善的粉末处理性能和储存行为。(2)热造粒条件（流体喷雾、冷却气体和产品储存温度）应适应乳液质量流速和基于配方的熔融和玻璃化转变温度范围，以使W/O或O/WO乳液体系中的二次W滴固化为玻璃态。这样，即使在长期储存间隔期间，也可以大大提高包封物质保存的最佳稳定性。在不同的产品储存时间间隔后，可能调整（i）W-滴相中的玻璃化转变和（ii）对包封的功能化合物的释放动力学的影响的动力学。为了将整体加工和产品相关项目结果相互连接，我们将完成过程-结构函数（PSF）和结构-性能函数（SPF）的推导，最终将耦合以接收总体过程-结构-性能关系（S-PRO2）。

The encapsulation of functional components (FC) is of broad interest for new product development in the industrial areas of pharmaceuticals, foods, cosmetics, fine chemicals as well as building and packaging materials. Particularly suitable structures for well-defined encapsulation of functional components in emulsion systems have been approved. If such emulsions can be stabilised, encapsulated FC’s can be protected/preserved under storage and further processing conditions as well as controlled release be applied. The reliable stabilisation of complexly structured emulsions can be best achieved by solidification. Consequently to get optimal stability and handling properties of emulsion systems in further production, consumer applications or for storage, it is desirable to bring such emulsions into powder form. A spraying technique coupled with cold solidification of spray drops (prilling) was our preferred choice. In the very successful first project steps (years 1-4) encouraging results concerning functional relationships between (i) geometrical design parameters of two phase spray nozzles, (ii) prilling process parameters (spraying pressure, spraying/prilling temperature, volume flow rate, volume flow rate ratio (fluid/ gas)) and (iii) resulting structural characteristics of spraying drops and prilling powder systems (drop / particle size- and shape distributions, phase morphology and structure preservation) could be achieved. Experimental and CFD simulation based studies provided further details concerning the dynamics of spray lamella breakup and spray drop size / drop-morphology development taking the non Newtonian rheological and structural emulsion properties into account. The complementation of our prilling process by a “post processing” step, an in-vitro gastric disintegration stirred reactor, allowed us to study prill-particle disintegration and coupled release kinetics measurements of functional compounds in a quantitative manner. In the new project step (is 5,6) the knowledge will be further developed in two main directions: (1) Developing a novel spray nozzle-concept, which superimposes pressure and centrifugal acceleration fields thus offering possibilities of a well defined spray filament breakup in the Rayleigh domain. Therefore large filament elongation shall be forced before the Rayleigh breakup proceeds and studied experimentally and by CFD simulation. This would allow to treat the spray particles fluid mechanically gentle and in addition reduce the width of the spray drop/particle size distribution. This lead furthermore to (a) largely improved preservation of encapsulated functional components, (b) better adjustable controlled release and (c) improved powder handling properties and storage behaviour. (2) The thermal prilling conditions (fluid spray - , cooling gas- and product storage temperatures) shall be adapted to the emulsion mass flow rate and the formulation-based melting- and glass transition tempera-ture ranges to be adjusted in such a way that the secondary W-drops in the W/O or O/WO emulsion systems solidify in the glassy state. With this, optimal stability for preservation of encapsulated substances even during longterm storage intervals could be much improved. Possibilities to adjust the kinetics of (i) glass transition in the W-drop phase and (ii) resulting influence on the release kinetics of encapsulated functional compounds will be quantified after various product storage time intervals. For interconnecting the overall processing and product related project results we will complete the derivation of Process-Structure Functions (PSF) and of Structure-Property Functions (SPF), which will finally be coupled to receive the overarching Process-Structure-Property relationships (S-PRO2).