Reference material development for calibration and verification of image-based particle analyzers.

The need is well recognized for suitable reference populations for calibrating and verifying the size and concentration accuracy of particle analysis instruments for use in the measurement of suspended protein particles in biopharmaceuticals. Polystyrene bead standards are normally used as a reference material for calibrating and validating particle analyzers. However, these standards, unlike protein particles, are easily detected and do not challenge the sensitivity of optical instruments.

Micro-flow imaging: flow microscopy applied to sub-visible particulate analysis in protein formulations.

The need to monitor, measure, and control sub-visible proteinaceous particulates in biopharmaceutical formulations has been emphasized in recent publications and commentaries. Some of these particulates can be highly transparent, fragile, and unstable. In addition, for much of the size range of concern, no practical measurement method with adequate sensitivity and repeatability has been available.