Personally, I’ve only briefly understood that the problem is there is no separate regulation for “improved generics/biosimilars.” Neither in the US nor in the EU.
Because to be a generic, it has to be completely identical. And then again, the whole point of nanoformulation is, of course, to improve properties.
So it has to go through a new drug application route. Which requires larger studies.
And this is the stumbling block for small drug delivery companies.