Criteria and worst-case approach
In order to avoid cross-contamination, ICH Q9 defines the acceptance criteria for each individual active ingredient produced in a multi-purpose plant on a risk basis.
Once the relevant limits are known, a worst-case scenario can be determined for the entire product range in order to set a limit for the entire cleaning validation. Costs and effort can be minimized by forming apparatus and product groups. For this purpose, it is recommended to evaluate the drugs with the highest toxicity, lowest solubility or properties that make them difficult to clean. Also an evaluation of the plant locations that are most difficult to clean is provided.