Chair of Solids Process Engineering, TU Dortmund University, Germany.
Chair of Solids Process Engineering, TU Dortmund University, Germany.
Int J Pharm. 2018 Sep 5;548(1):237-243. doi: 10.1016/j.ijpharm.2018.06.069. Epub 2018 Jun 30.
The low bioavailability of poorly water-soluble drugs is currently one of the major focuses of pharmaceutical research. One strategy currently being investigated to overcome this limitation is to decrease the particle size of the active pharmaceutical ingredients (API). An innovative process for this is spray drying with spray conditioning, which can produce submicron particles. One challenge resulting from this process is the recovery of these dispersed particles from a gas flow. Electrostatic precipitation is a common technique for air purification purposes, but an adapted electrostatic precipitator (ESP) design is necessary to achieve high collection efficiencies. The ESP design in this work uses the precipitation method of Penney filters which separates charging and collection into two stages. The ESP dimensions depend on various assumptions and simplifications. Several experiments were conducted to assess the performance of the ESP and characterize its behaviour in long-term tests. The crucial parameters in the charging process are the residence time as well as the operating voltage. These constraints were examined to enhance the collection efficiency. Based on these tests it was possible to determine a suitable charging length as well as the dimensions of the collection stage. In conclusion, an ESP customized for collecting particles in the range of 0.1-1 µm was designed, built and tested, and collection efficiencies higher than 99% were achieved for submicron particle size distributions. For a robust process continuous cleaning of the charging stage is necessary.
目前，水溶性差的药物生物利用度低是药物研究的主要关注点之一。为克服这一限制，目前正在研究一种策略，即减小活性药物成分（API）的粒径。喷雾干燥与喷雾调节是一种创新的工艺，可以生产亚微米颗粒。该工艺带来的一个挑战是从气流中回收这些分散的颗粒。静电沉淀是空气净化的常用技术，但需要对静电除尘器（ESP）进行适应性设计，以实现高效率的收集。这项工作中的 ESP 设计采用了 Penney 过滤器的沉淀方法，将充电和收集分离成两个阶段。ESP 的尺寸取决于各种假设和简化。进行了多项实验来评估 ESP 的性能并在长期测试中对其行为进行了表征。充电过程中的关键参数是停留时间和工作电压。这些约束条件被检查以提高收集效率。基于这些测试，可以确定合适的充电长度以及收集阶段的尺寸。总之，设计、制造和测试了一种专门用于收集 0.1-1μm 范围内颗粒的 ESP，实现了亚微米粒径分布的收集效率超过 99%。为了实现稳健的工艺过程，需要对充电阶段进行连续清洁。
