Best Practices for Transferring Analytical Methods

The goal of transferring analytical methods is to ensure that the receiving laboratory produces the same results as the transferring laboratory, despite the differences between them. Health regulators often require analytical method transfers to external testing sites to guarantee the quality of medicines and to enable effective testing in stability studies.

There are three main approaches for transferring analytical methods (as per USP 1224), each its particular usability:

• Comparative transfer, which is used for methods already validated at the transferring laboratory or by a third party.

• Co-validation, which is the transfer of analytical methods from a development to a receiving unit, including them as a part of the validation team at the transferring unit and thereby obtaining data for the assessment of reproducibility.

• Revalidation, which is employed when the sending laboratory is not involved in the testing or there is a need to supplement the original method validation.

This article outlines several best practices that aid in creating methods that are replicable and fulfill regulatory requirements.

Consider the factors that affect the transfer of analytical methods

Even small differences can hinder the replication of methods across facilities. Often, method transfers involve laboratories that do not have the same instruments or that operate under slightly different configurations, which could affect the generated results.

Therefore, when planning how to transfer analytical methods, it is important to consider factors that influence results, such as prior experience, available infrastructure, required analytical skill sets, method complexity, familiarity with the technique, required accuracy, available time and resources, and the stage of process development, among others.

Once these factors are identified, it is necessary to decide how they will be assessed in order to identify risks, categorize their severity, and plan how to mitigate them.

Build up the robustness of methods

Since the success of the transfer depends on consistent results, the transferring laboratory must develop robust analytical methods that account for the identified factors. This requires establishing clear method parameters and acceptance criteria that achieve reproducibility and flag result deviations.

In the case of co-validation, strong collaboration between the receiving and transferring teams helps to build the robustness of a transfer method. Thus, planning and coordination should begin months before the transfer takes place. This collaborative process should include capturing critical information for method performance, outlining method requirements, determining the instrumentation needed, setting up transfer requirements, training,  and drafting the manuals required to execute the methods.

Use clear language when writing documentation

Two major challenges to maintaining product consistency are the subjective interpretation of instructions and reducing the documentation process to a checklist. While technical expertise is expected, instructions must remain clear and understandable to laboratory personnel with varied levels of technical skill.

Highly detailed procedures and strict parameters help generate consistent results regardless of the scientist’s skill level. One way to achieve this is by thoroughly documenting procedures and ensuring that the language in the method transfer documentation allows for only a single interpretation.

By assessing factors that affect results, addressing method risks, promoting collaboration between internal and external teams, and writing clear documentation, it is possible to transfer analytical methods successfully. The complexity of a transfer increases as more partners and requirements are involved; hence, pharmaceutical companies should focus on developing methods that are both robust and replicable across facilities with different capabilities.