Drug Substance & CMC Development Tool Box: Selection of cGMP Starting Materials (RSMs)

cGMP Starting Materials (Regulatory or Registered Starting Materials, ‘RSMs’) represent the formal start of cGMP (current Good Manufacturing Practice) control, and potential start of validation for a given Drug Substance/Active Pharmaceutical Ingredient (API) manufacturing process.

This highlight article outlines main selection factors described in ICH Q11 and Q&A guides, and presents several examples of their application.   

Key selection factors include:

  • Placement in the overall synthesis, including separation from common reagents and from the Drug Substance
  • Material characterization, analytical and stability knowledge
  • Impurity profile and management, in particular of high risk impurities (e.g. DNA-reactive impurities or nitrosamines)
  • Specification tests and criteria, and contribution to overall control strategy
  • Source selection and manufacturing controls, including knowledge and management of process and process changes

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