Quality by Design for Analytical Methods

372 The Pharmaceutical Journal (Vol 284) 17 April 2010 The pharmaceutical industry has traditionally controlled analytical methods via a well defined sequence of development, validation and transfer exercises in line with agreed standards such as the quality guidelines Q2 of the International Conference on Harmonisation of Technical Requirements for Registration of Pharmaceuticals for Human Use (ICH Q2). But such an approach limits the scope for technological innovation or improvements in quality or efficiency of methods for established products. In a keynote lecture, Imogen Gill, from Pfizer, described the application of principles of quality by design (QbD) in method life cycle management. It all starts, she said, with creativity — the ability to produce a new concept through the imagination. It is the production of novel ideas and inventions. Invention is the first occurrence of an idea for a new product or process, whereas innovation is the process of successful implementation of the concept to create value. Reasons why the industry needs to be innovative range from financial benefits to improving the quality of life for society as a whole. Developing new medicines is a long, risky and expensive business (current estimates being the investment of $0.8–1.3bn over 15 years) and the industry must take the opportunity to improve the situation by identifying winners early and carrying out some procedures in parallel.The drivers for change in developing an analytical strategy include the urgent need to reduce costs in product development and in production while limiting any increase in risk, and the opportunities presented by advances in science and technology. QbD is defined as a systematic approach to development that begins with predefined objectives and emphasises product and process understanding based on sound science and quality risk management. To apply the QbD approach for analytical methods the concept of an analytical target profile (ATP) has been developed.ATP is the documentation of the predefined objectives for the method.The justification of the characteristics and criteria included within it, therefore, becomes critical. An example of an ATP would be: “This method needs to be able to measure analyte A in the presence of B, C and D over the range E to F with a precision of G and an accuracy of H.”Significantly, the ATP does not describe the method, but stipulates the characteristics of the method, so that it represents a potential opportunity to facilitate innovation and reduce the burden when variation of the licence is proposed. Adoption of QbD for analysis will result in the method performance requirements being more closely linked with process needs, concluded Ms Gill.