Automated Solutions for USP Subvisible Particulate Testing

Companies manufacturing parenteral drugs and ophthalmic solutions need to test for subvisible particulates using a liquid particle counter. Parenteral drugs must be tested according to USP <788> or <787> for therapeutic proteins. The globule size of lipid injectable emulsions is tested per USP <729> for both the mean size and the percent > 5µm (PFAT5). Ophthalmic solutions are tested following USP <789>.

Choosing the best instrument for these tests involves matching the measurement requirements to system capabilities.

Important parameters include size range, minimum sample volumes (especially for USP <787>), validation, and automation. While the test requirements have not changed very much over the past several decades, instrument technology has improved considerably; both hardware and software.

The AccuSizer® system is the most advanced liquid particle counter used for these tests providing the highest specifications and sophisticated automation. Our unique single particle optical sizing (SPOS) sensors have the widest dynamic range – reporting results to the smaller sizes useful for differentiating stable protein formulations. Low sample volumes, push/pull mixing, and sample recovery facilitate protein testing using a minimal sample amount. An autosampler and microplate analyzer can automate the measurements, proving high throughput capability.