Probably the initial negotions between the manufacturers and, to some degree, the suppliers - the bulk price. Once that's settled the 'price per prescription' gets printed in the drug tariff.
In theory it's to stop pharmacy buying groups (where a group of independent pharmacies club together) buying items that are cheap one month but know the reimbursement price is going up next month. There may be other reasons but stockpiling and redistribution has been a problem in the past.
But it stands to reason that the prices are probably going to rise due to Brexit, so wont stockpiling have already been started by these groups? Surely they must know what drugs are most in demand and what ones are probably most at risk from price fluctuations?
I guess I'm just struggling to see how these NDAs apply to this under these circumstances.

