I don't think you or ken47 have more than a layman's understanding of the subject.
Daraprim is a brand name. Pyrimethamine is the active ingredient.
When you create a generic, it must be checked that it is roughly equivalent to the approved version. Meaning there are no impurities and you digest the drug about the same rate which is determined mostly by the inactive ingredients. This process is relatively fast, often taking 1 year or less compared to the decades it takes to approve a new drug. And if you are going to be saving medicare millions of dollars, you can bet it is going to be put at the top of their todo list and will probably be tested within days.
To say that this is a government monopoly because you can't sell your drug from day 0 without any testing is quite a stretch.
>I don't see how pharma is not a free market in this case.
It's a monopoly because it has government-granted monopolistic power. Generics can go through the approval process and be granted similar power, making a duopoly.
That doesn't change the fact that it is a monopoly right now and definitely not a free market. Seems like someone has a case of confirmation bias.
Others could go through the process to be Medicare approved, but that doesn't change that it's not subject to a free market.