QbD Validation Strategies: The Process Design Phase Part 1

By Anil Doshi, R.Ph., Ph.D, President, Infinity Pharmaceutical Consulting

Process validation comprises three stages that take place over the life cycle of the pharmaceutical drug product. (See Figure 1.)  Stage 1, which will be the focus of this column, is referred to as process design, and encompasses pharmaceutical drug products in early development. Stage 2 is referred to as process qualifications, and includes pharmaceutical drug products at a stage prior to commercialization or prior to submitting a New Drug Application (NDA) or Abbreviated New Drug Application (ANDA).  Stage 3 is referred to as continued process verification and includes pharmaceutical drug products that are commercialized and currently marketed products with completed prospective validation. Products that fall in between these categories will need to be assessed on a case-by-case basis and can be placed in the appropriate stage using a "gateway" approach.