Selling drugs in hospitals is selling, but what do you mean by "selling behavior in the sense of patent law"? You're suing him for infringement? If the manufacturer of his medicine pays the use fee to the obligee, the sales of the hospital will not infringe; On the other hand, even if the hospital's behavior is infringing, if the hospital can prove that "selling unknown patented products manufactured and sold without the permission of the patentee or products directly obtained according to the patented method can prove the legal source of its products", it will not be liable for compensation.
In other words, even if the hospital is convicted of infringement, the possibility of your compensation is extremely small.