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

功能成分（FC）的封装在制药，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中具有广泛的兴趣。特别适合于在乳液体系中定义良好的功能组分包封的结构已被批准。如果这些乳剂可以稳定，则封装的FC可以在存储和进一步处理条件下进行保护/保存，并应用控制释放。对于结构复杂的乳剂，固化是最可靠的稳定方法。因此，为了在进一步的生产、消费应用或储存中获得乳液系统的最佳稳定性和处理性能，需要将此类乳液制成粉末形式。喷淋技术加上冷凝固的喷雾滴（造粒）是我们的首选。在非常成功的第一个项目步骤（1-4年）中，关于(i)两相喷嘴的几何设计参数，（ii）造粒工艺参数（喷涂压力，喷涂/造粒温度，体积流速，体积流速比（流体/气体））和（iii）喷涂液滴和造粒粉末系统的最终结构特征（液滴/颗粒尺寸和形状分布）之间的功能关系的令人鼓舞的结果，可以实现相形态和结构的保存。基于实验和CFD模拟的研究为考虑非牛顿流变性能和结构乳化液性质的喷雾片层破裂动力学和喷雾液滴尺寸/液滴形态发展提供了进一步的细节。通过一个“后处理”步骤，即体外胃解体搅拌反应器，补充了我们的造粒过程，使我们能够定量地研究颗粒-颗粒的分解和功能化合物的耦合释放动力学测量。在新的项目步骤（5,6）中，知识将在两个主要方向上进一步发展：(1)开发一种新的喷嘴概念，它叠加了压力和离心加速度场，从而提供了在瑞利域中明确定义的喷雾细丝破裂的可能性。因此，在进行瑞利破碎之前，需要强制长丝大幅伸长，并通过实验和CFD模拟进行研究。这将使喷雾颗粒流体在机械上变得温和，此外还可以减少喷雾滴/颗粒尺寸分布的宽度。这进一步导致(a)大大改善了封装功能成分的保存，(b)更好的可调节控制释放和(c)改善了粉末处理性能和储存行为。(2)热造粒条件（流体喷射温度、冷却气体温度和产品储存温度）应适应乳化液的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乳化液体系中的二次W-滴凝固在玻璃态。这样，即使在长期储存间隔内，也可以大大提高封装物质保存的最佳稳定性。在不同的产品储存时间间隔后，调整(i) w滴相玻璃化转变和（ii）对封装功能化合物释放动力学的影响的可能性将被量化。为了连接整个加工和产品相关的项目结果，我们将完成过程-结构函数（PSF）和结构-属性函数（SPF）的推导，它们最终将耦合以获得总体过程-结构-属性关系（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).