New standards for alternative methods

Pharmaceutical microbiology is undergoing significant developments, affecting both analytical technologies and the criteria used to assess and implement them in quality control laboratories. The need to obtain results more rapidly, particularly for medicinal products with a short shelf life, must be balanced against the requirement to demonstrate that alternative methods are suitable for their intended purpose and perform appropriately compared with established pharmacopoeial procedures.

These issues were among the topics addressed at Microbiology on the Move, a symposium organised by the European Directorate for the Quality of Medicines & HealthCare (EDQM) in Strasbourg from 13 to 15 October 2026. The event brought together regulators, industry representatives and international stakeholders to examine developments in microbiological quality standards and opportunities for greater international harmonisation.

The discussions took place against the background of ongoing work by the European Pharmacopoeia Commission (EPC). In March 2026, the Commission adopted a revision of general chapter 5.1.6, Alternative methods for control of microbiological quality. Published in Issue 13.2 of the European Pharmacopoeia (Ph. Eur.) in July 2026, the revised chapter will become applicable on 1 April 2027.

What Is Changing in General Chapter 5.1.6?

The revision of general chapter 5.1.6 reflects the need to bring pharmacopoeial guidance into line with advances in analytical technologies and experience gained from their practical application.

According to the EDQM, the updated chapter includes a comprehensive revision of the technologies described, removing references to obsolete methods and incorporating more recent approaches.

Although the overall framework for implementing alternative methods remains unchanged, the revised text provides greater clarity on the respective responsibilities of technology suppliers and users.

Another significant development is the introduction of risk-based validation strategies. These may allow laboratories to make appropriate use of existing data and assess several implementation activities simultaneously.

The intention is to improve the efficiency of method implementation while maintaining the scientific evidence needed to demonstrate that a method is suitable for its intended application.

For pharmaceutical laboratories, the implications are primarily methodological. Introducing an alternative technology requires a clear understanding of the performance characteristics relevant to its intended use, the supporting evidence already available and the additional studies necessary under the specific conditions of application.

Rapid Microbiological Methods for Short-Shelf-Life Products

One of the central topics of the EDQM symposium was the potential role of rapid microbiological methods in the testing of medicinal products for which conventional microbiological testing times present particular challenges.

This is especially relevant to certain advanced therapy medicinal products (ATMPs) and radiopharmaceuticals, whose limited shelf life may make it difficult to complete conventional microbiological tests before administration.

Methods capable of delivering results more rapidly may provide microbiological quality information within timeframes that are better aligned with the characteristics and clinical use of these products.

However, analytical speed alone does not establish the suitability of a method.

Factors such as sensitivity, specificity, detection capability and other relevant performance characteristics must be assessed, together with the possible influence of the product matrix and operating conditions.

Live biotherapeutic products present additional analytical challenges because they contain viable microorganisms as active components.

Their complexity calls for careful assessment of the applicability of microbiological testing methods, including their ability to distinguish the microorganisms of interest from potential contaminants.

Short-shelf-life medicinal products and emerging product categories were therefore among the areas highlighted by the EDQM for further discussion of alternative microbiological approaches.

Towards a Harmonised Assessment of Microbiological Methods

Alongside the revision of general chapter 5.1.6, the European Pharmacopoeia Commission is pursuing a separate initiative intended to facilitate the use of rapid microbiological methods.

In March 2026, the Commission approved the establishment of a working party dedicated to the technical development of the certified review of microbiological methods per the European Pharmacopoeia, known as cMEP.

The initiative aims to establish a harmonised scientific review of validation and comparability data for rapid microbiological methods, in accordance with European Pharmacopoeia requirements.

Its method-centred approach is designed to facilitate access to scientific evidence supporting the implementation of these technologies.

An important distinction must nevertheless be made between the general scientific assessment of a method and the demonstration of its suitability for a specific medicinal product.

The cMEP initiative, which remains under development, does not remove the need to establish that an analytical method is appropriate for the product matrix, intended application and operating conditions concerned.

Indeed, the proposed certification concept does not cover product-specific validation and comparability activities.

This distinction matters for pharmaceutical manufacturers and quality control laboratories. A harmonised scientific assessment could help reduce duplication of effort and facilitate the adoption of new technologies, but it would not automatically transfer responsibility for demonstrating product-specific suitability from the user to the technology supplier.

Conventional Microbiological Methods Are Also Under Review

The evolution of microbiological quality standards extends beyond alternative technologies.

The EDQM symposium also addressed internationally harmonised European Pharmacopoeia chapters, including the sterility test (2.6.1) and the chapters covering microbiological examination and quality requirements for non-sterile products (2.6.12, 2.6.13 and 5.1.4).

The purpose of these discussions was to examine whether the existing texts remain fit for purpose, particularly when applied to challenging product matrices and emerging medicinal products, and to identify potential areas for revision.

It is important to distinguish this scientific and regulatory dialogue from the formal adoption of new pharmacopoeial requirements.

The inclusion of a topic in the symposium programme does not, in itself, constitute an amendment to the European Pharmacopoeia.

Implications for Pharmaceutical Quality Control Laboratories

The revision of general chapter 5.1.6 provides pharmaceutical companies with an opportunity to reassess their strategies for introducing and validating alternative microbiological methods.

For quality control and quality assurance functions, several aspects are particularly relevant: defining appropriate method performance requirements, demonstrating comparability with reference methods, making justified use of existing data and establishing clear responsibilities between technology suppliers and users.

These developments also have implications for professional expertise.

The implementation of alternative microbiological methods requires an understanding of microbiology, analytical development, risk assessment and regulatory requirements, together with the ability to integrate these disciplines into a coherent validation strategy.

Adopting an alternative method should therefore be regarded as a documented scientific assessment of its suitability for the intended purpose, rather than simply replacing one analytical technology with another.

The initiatives undertaken by the EDQM point towards a more flexible approach to microbiological quality control, supported by clearer criteria for demonstrating analytical performance.

For the pharmaceutical industry, the challenge will be to translate these developments into efficient testing strategies while maintaining scientific robustness and the level of assurance required to safeguard the microbiological quality of medicinal products.

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