What does USP <1787> cover and how is it different from USP <787>?

USP <1787> Informational chapter Measurement of Subvisible Particulate Matter in Therapeutic Protein Injections supports chapter <787> by providing additional guidance on sizing, counting and characterization guidance for protein therapeutic products. As an informational chapter, <1787> is focused on determining and characterizing the inherent protein population to support the scientific development process for therapeutic protein products. Unlike USP <787>, <1787> provides no guidance on subvisible particles (2-µm to 100-µm range).