FlowCam Blog

Discriminate particulates in protein therapeutics using particle size and shape 

Written by Michelle Devoe | January 23, 2018

Your current particle analyzer counts the subvisible particles in your protein therapeutic. A particle size distribution curve is generated and confirms you are within the required USP <788> and <787> standards; your particle count is equal to or less than 6,000 particles ≥ 10 µm and 600 particles ≥ 25 µm.  How do you verify that the detected particles are your desired product and not contaminants or other extrinsic, intrinsic, or inherent particles? 

The FlowCam particle analyzer and its particle analysis software VisualSpreadsheet® enable you to create morphological filters during post-processing to discriminate, analyze, and verify the particulates present in your injectable therapeutic formulation. 

Classify Particulates Using Morphology 

In this study, a sample of polyclonal IgG from a lubricated, prefilled syringe was analyzed with the FlowCam® particle analyzer and its particle analysis software VisualSpreadsheet® An image of each subvisible particle was captured and over 40 morphological characteristics, including size, were measured from each image. A morphological filter was created in VisualSpreadsheet to discriminate images of silicone oil from other particulates present in the sample. Of the 40+ morphological characteristics to choose from, aspect ratio, circularity (Hu), and the application of a statistical filter, combined to create the most effective filter to discriminate silicone oil images from images of other particulates within the sample. 

After the morphological filter was applied, it was discovered that 26% of the sample particulate was silicone oil. With this new data, it is now possible to perform additional morphological and statistical analyses on this population. Numerous morphological filters can be created in VisualSpreadsheet to discriminate and analyze other particulate populations, including different size ranges and morphologies. 

Improved Analyses, Improved Injectables

Verify the particulate in your injectable therapeutic is particulate you want. Morphologically and statistically analyze the different particulate populations present by applying morphological filters created during post-processing. See what the particulate in your injectable therapeutic formulation is composed of.