Process validation is an essential part of medical device manufacturing, ensuring that a continuous process manufactures products according to predefined requirements. According to the Guidance Management Systems - Process Validation Guide (GHTF) and the US Food and Drug Administartion (FDA), process validation is a critical pillar for risk mitigation during production.
Process validation is defined as the documented confirmation that a process delivers reproducible results that meet predefined requirements. This proof is crucial to ensure the safety and quality of the manufactured products. The selection of products to be validated is based on various guidelines, including the GHTF guideline and DIN EN ISO 13485:2021-12. In general, processes should be validated if the results cannot otherwise be verified before use.
The decision between validation and 100% verification depends on various factors, including economic considerations. For properties such as sterility, 100% verification is not possible - especially complex processes usually require validation, while other properties can be verified during the process. A structured and transparent approach to decision making is essential. This includes the documentation of all relevant processes and their impact on the safety and performance of the products. The steps in the decision-making process and the resulting decisions must be clearly documented in order to meet regulatory requirements and successfully pass audits.
There are also properties that can neither be fully verified nor considered as part of a validation, as long as no safety or performance risks arise from deviations.
To describe the validation process, let's look at the analysis of filling and packaging processes for a manufacturer in the medical technology sector. This includes an identification of relevant product and process characteristics, as well as an assessment of their importance in terms of safety and performance. The risk analysis is used to make decisions for validation, using methods that show the probability of finding defects. Operational qualification (OQ) ensures that acceptable results can be achieved even under difficult conditions. This primarily includes the definition and documentation of "worst-case scenarios", as well as procedures for process changes. Performance quality (PQ) aims to deliver reliable results under normal operating conditions. This includes the evaluation and documentation of variations, as well as the definition of the number of batches required for a validation. All steps during a validation must be documented, including planning, reporting and parent documents.
Process validations, although seemingly complex, need not be a burden. With clear strategies, structured approaches and clear guidelines, manufacturers and suppliers of medical devices can fulfill the given requirements while ensuring quality during production. It is important to identify relevant properties, validate processes and document all decisions transparently. In this way, not only can regulations be complied with, but the safety and quality of the products can also be continuously improved.
