Meeting USP Standards for Subvisible Particulate Matter with FlowCam LO

Assessing subvisible particle content is a required quality control step for biotherapeutics and other parenteral drug products.

The United States Pharmacopeia (USP) and in particular, USP <788> specifies that companies monitor the number of subvisible particles larger than 10 and 25 μm present in any commercialized parenteral drug product−including most protein, gene, and cell therapies. It also requires this testing be done using either light obscuration (LO) or membrane microscopy, the former of which is the preferred technique. These requirements are harmonized with those in the European and Japanese pharmacopeia’s.

Light obscuration measurements have been shown to exhibit some limitations for analysing common particles in biotherapeutic formulations. These measurements are relatively insensitive to translucent particles like protein and viral vector aggregates and will undersize and often undercount these particles. They also do not capture any information about the shape and source of the particles in the sample.

Flow imaging microscopy (FIM) is an orthogonal subvisible particle measurement technique that mitigates the issues of LO, offering greater sensitivity to translucent particles as well as information about particle type. USP recommends using FIM as an orthogonal technique to LO as part of routine quality control of biotherapeutics via USP <1788>.

FlowCam LO instruments provide an innovative particle characterization solution by allowing researchers and technicians to capture both the required light obscuration and the recommended FIM subvisible particle data using a single instrument and single sample aliquot. In addition to capturing two orthogonal subvisible particle measurements, FlowCam LO provides light obscuration measurements that meet the requirements for USP <788> and <787> testing, as well as many of the recommendations for LO measurements found in USP <1787> and <1788>.

FlowCam LO is available in the UK from Meritics.