That's a great question.
If you look at a traditional pharmaceutical that goes through a retail pharmacy, the manufacturer would sell it to a wholesaler or distributor. The distributor in turn would sell it to the retail pharmacy. The retail pharmacy would sell the drug to the patient, and that patient would be reimbursed by the public or private plan, or would pay cash.
The money to the pharmaceutical company comes from the wholesaler or distributor. In some cases they'll sell directly to the pharmacy. They typically may sell directly to the hospital or a hospital buying group. Usually they sell into the distribution chain and it's usually a distributor or wholesaler or potentially a hospital that cuts the cheque.