Well you either remove all the bureaucracy around drug testing and approval and make it cheap to develop a new drug, or you prevent drug makers from making money if they are successful at developing a new molecule. But if you do both, all you will get is zero research. Right now it takes 10s of billions in R&D budget to bring new molecules to the market, which is insane.
Or you pay them directly. Most countries have research funding. Since there's no way to know what you'll find or how long it will take, research doesn't fit well in the capitalist model. Makes much more sense to apply a fixed effort and accept whatever results come out, but only the government can do that — or a rich monopoly like Bell.