An Analysis of Visible Particulates Introduced to Liquid Pharmaceuticals By Disposable Syringes

Microplastics, as we know, are found in nearly all biological systems on Earth, as well as the food we eat and the water we drink. Even highly-regulated pharmaceutical disposables such as syringes, whose manufacturing quality controls aim to limit the incidence of particulates, may introduce microplastics to liquid drugs and substances. However, due to the nature of some cellular-based therapies, it may be difficult to notice these particulates. For example, the high concentration of cells in a final product may obscure the presence of translucent or nearly-clear particulates. Conversely, these particulates may be more evident in clear or transparent final products, including non-cell-based therapies or plasma. In this work, we have analyzed the generation of visible particulates by syringes in mock liquid products, by way of visual inspection in 50mL cryobags, a common container used in cellular therapies and other treatments. The results indicate that in a clear liquid with dye added to provide contrast, and using a black and white inspection background with LED light, nearly all syringes tested introduced particulates to the mock product. In response, and when appropriate, we recommend that syringe filters with a 0.2um pore size or smaller be used to sequester particulates when performing the final fill of manufacturing processes.