most of good design software allows you to create space profiles that you would put specific air change requirements.
many software packages have automatic assistant to help you to calculate ASHRAE, CIBSE, DIN or similar requirements, but you can never ever rely on it to be completely accurate, but have to check it vs. code requirements, that's only rough help to speed up your work.
for pharma, i don't believe there is such assistant, and pharma requirements are so detailed and specific that you have to make your profiles based on that yourself.
i don't exclude possibility that some large design firms specialized in pharma designe did not develop some tailored packages, but they will never release it to the outside.
as regards to pressure differential, there is another thread here where you can read discussion about it.