Pharmaceutical Materials Science and Engineering Laboratory, Department of Pharmaceutics, College of Pharmacy, University of Minnesota, Minneapolis, MN 55455, USA.
Alexanderwerk Inc, Montgomeryville, PA 18936, USA.
Int J Pharm. 2022 Jun 10;621:121803. doi: 10.1016/j.ijpharm.2022.121803. Epub 2022 May 5.
Roller compaction (RC) is a common granulation process for manufacturing solid dosage forms. However, its applicability to the growing number of powders with very low bulk densities and high cohesiveness can be limited due to poor powder feeding. Although deaeration with a vacuum in the feeding line is an effective approach to enhance the powder feeding performance, a systematic assessment of its effects on RC process is lacking. In this work, we have examined the effect of vacuum on the processability of RC using an extremely poorly flowing powder, colloidal silica, and two grades of microcrystalline cellulose (MCC). A processable range is defined by roll speed and screw speed that attain stable feeding under the roller-gap controlled mode. A 0.35 barg vacuum level was sufficient to make the colloidal silica processable and a higher vacuum level solved the subfeeding issue and significantly expanded the RC operation range. In contrast, deaeration slightly narrowed the processable range for MCC PH105 and PH101, while only minimally affects the relationship between roll speed and screw speed. The effects of vacuum on the processability of these materials qualitatively correlated with the sensitivity of their bulk densities to pressure. A better understood effects of material properties (bulk density), process parameters (roller gap), and deaeration (vacuum level) on RC processability of powders help to determine an appropriate use of a vacuum line to improve the RC process.
辊压（RC）是一种常见的制粒工艺，用于制造固体制剂。然而，由于粉末给料性能差，对于越来越多具有极低堆积密度和高内聚性的粉末，其适用性可能受到限制。虽然在给料线中使用真空脱气是增强粉末给料性能的有效方法，但对其对 RC 工艺影响的系统评估还很缺乏。在这项工作中，我们研究了真空对使用非常不易流动的粉末（胶体二氧化硅）和两种微晶纤维素（MCC）的 RC 工艺加工性能的影响。可加工范围定义为在辊隙控制模式下达到稳定给料的辊速和螺杆速度。0.35 barg 的真空度足以使胶体二氧化硅可加工，而更高的真空度解决了给料不足的问题，并显著扩大了 RC 操作范围。相比之下，脱气略微缩小了 MCC PH105 和 PH101 的可加工范围，而对辊速和螺杆速度之间的关系影响很小。真空对这些材料可加工性的影响与它们的堆积密度对压力的敏感性定性相关。更好地了解材料特性（堆积密度）、工艺参数（辊隙）和脱气（真空度）对粉末 RC 可加工性的影响有助于确定适当使用真空线来改善 RC 工艺。
