International harmonization: understanding the bridges between USP 788 and the European Pharmacopoeia 2.9.19

Manufacturers of injectable drugs, ophthalmic products or parenteral solutions must demonstrate control of non-visible particles in accordance with regulatory requirements that largely overlap between USP <788> and the European Pharmacopoeia 2.9.19. The operational difficulty lies less in the control principle than in interpreting test conditions, selecting the analytical method, preparing samples and providing the documentary justification expected in an international context. A comparative review helps identify useful points of alignment for global release and method transfer strategies.

The first challenge is to correctly characterize the product: route of administration, unit volume, formulation type, sensitivity to sample preparation and routine control strategy. A useful comparison between the two standards is not limited to aligning thresholds; it must also take into account the drug’s intended use, internal specifications and the associated quality documentation. This approach is essential for global dossiers involving multiple markets.

An analytical method is not limited to a one-off test. It must be developed or adapted to the matrix, then validated or pre-validated according to its intended use, before being transferred under controlled conditions. The receiving laboratory must demonstrate its ability to apply the method correctly, with defined performance criteria, comparability tests and ongoing monitoring through statistical control tools where relevant.

The reliability of testing depends as much on the method as on the environment in which it is carried out. A laboratory with a broad analytical platform, qualified equipment and an organization adapted to GMP requirements can secure both routine testing and specific studies. This capability is decisive when particle control is part of a broader issue involving purity, contamination, container-content interactions or process drift.

FILAB supports manufacturers in understanding and implementing the analytical requirements applicable to healthcare products, in an environment compliant with GMP requirements. The laboratory is involved in the development, validation, transfer and performance monitoring of analytical methods, with an approach based on pharmacopoeias, international guidelines and applicable quality expectations throughout the analytical lifecycle. This expertise makes it possible to build robust protocols that can be used in routine operations and defended during audits or inspections.

The light obscuration method is often preferred for its speed and relevance in routine use, but it is not universally sufficient. Depending on the matrix, viscosity, opalescence, presence of interferences or particle behavior, a microscopic method may be required or justified as a complement. The robustness of the approach then depends on equipment qualification, sampling control, operator training and traceability of test parameters.

In an international context, it is often necessary to demonstrate that the same analytical strategy can meet several regulatory frameworks without losing relevance. This requires clear documentation of technical choices, method limitations, accepted deviations, acceptance criteria and comparability conclusions. This logic is particularly useful during quality audits, site changes or formulation changes.

The value of a multi-technique laboratory is its ability to extend the analysis in the event of an atypical result. An investigation may require complementary approaches to physicochemical characterization, impurity identification, elemental analysis or contaminant screening. This cross-functional capability speeds up root-cause understanding and facilitates the implementation of relevant corrective actions.

FILAB offers solution-oriented support to help manufacturers compare requirements, define a consistent analytical strategy, secure validations, and document method transfers. The laboratory takes a pragmatic approach based on international pharmaceutical standards, experience in regulated environments, and the ability to adapt testing to the real constraints of products. This combination is particularly relevant for companies seeking to harmonize their practices across multiple marketing regions.