Quality control strategy formulation

Risk based regulatory scrutiny that relates to the level of scientific understanding of how formulation and manufacturing process factors affect product quality and performance and the capability of process control strategies to prevent or mitigate risk of producing a poor quality product. 

Quality control of acellular pertussis vaccines presents particular problems related to the various methods used for preparation of the active components, the different compositions of the final formulations, and different amounts of antigen. Researchers in the National Institute for Biological Standards and Control in the UK have presented a strategy capable of addressing the key problem areas likely to be encountered with all existing types of acellular pertussis vaccines and combinations (2). Their proposal could be considered as a starting point for improvement of quality control programs for these vaccines. 

An effective program of process control must aim to manufacture or formulate product which meets the specifications consistently, and ensure that only acceptable products are released from each step of the overall process. This makes process control a key operational element of quality assurance strategy. Recently, the food industry has been influenced by the pharmaceutical industry where process analytical technology (PAT) is becoming compulsory. The main principle is that quality should be designed or built-in to a process or product. 

In this paper an industrial semibatch polymerisation process is considered. In order to guarantee the product quality particularly controlled reaction conditions are necessary. The general aim of this work is to ascertain optimal state and control profiles and to develop a model-based control scheme. As a first step, this paper introduces the dynamic model, which is validated with experimental data, and describes the optimisation approach. An aim of the work is to assess the possibilities of the commercial flowsheet simulator CHEMCAD in the optimisation of the performance of semibatch polymerisation processes. Finally the formulation of the mathematical optimisation problem, solution strategies and their implementation in CHEMCAD are discussed. 

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