Lot # of Raw Material (API) in Process Validation Sequence

Dear all,
I have several questions around the batch number of API used in process validation:

  1. Should a sequence of validation (3 batches) use one lot of API?
  2. If we could use different lot, could we use more than one lot of API in 1 production batch?
    Thanks in advance.


It is generally preferred that validation be carried out on different lots of API in validation batches without mixing 2 lots if possible. SO that to understand that the process is validated with different lots and behaves same later on.