Case Studies on Changes and Proposed Process Development Approaches Reflecting Applicability of PDA .

Vaccines are complex and a very diverse group of products with relatively long product life cycles. The manufacturing programs for these vaccines need to be continually updated to comply with evolving regulatory expectations. Members of the Parenteral Drug Association (PDA) Vaccines Interest Group (VIG) authored and published PDA (TR 89), which seeks to provide context to vaccine developers and manufacturers regarding key aspects of new or legacy vaccines such as control strategy from process development to vaccine life cycle management, comparability and life cycle management including technical, validation, quality, and regulatory perspectives. To further explain and illustrate the concepts and topics discussed, seven relevant situations were selected as either case studies associated with changes implemented or proposed process development strategies, which are discussed in this article. The situations described are: working cell bank, modification or update of externally supplied product contact components for vaccine manufacturing, raw material change, new product at an existing site, vaccine development acceleration by leveraging existing platforms, selection and implementation of potency method, and modeling for stability forecast prediction. For each situation, the applicable key concepts from TR 89 are discussed as follows: Control Strategy, Prior Knowledge, Relying on Pharmaceutical Quality System (PQS), Classification of Parameters, Validation Approach, Use of a Risk-Based Approach, Comparability, Use of ICH Q12, and Additional Regulatory Considerations.