Several drug companies proposed twice for a duel patent to include CoQ10 in with their statins but were turned down on account of the cost.
I'm not a patent expert . . . . . . by my wife is.
Merck obtained a patent in 1990 for a statin with CoQ10 combined pill, I mention pill because it's delivery is part of the patent.
https://www.functionalmedicineuniversity.com/statin-CoQ10.pdf
The way patents work means that only one entity (person, company) will obtain a patent, any further applications will be rejected because they will not pass the novelty step (there would be prior art). Obtaining a patent isn't cheap but companies like Merck will have their own attorneys in their own country and may employ other firms of patent attorneys to obtain the patent in other countries. Patents are never refused because of cost, but a company may decide not to pursue it's application because of cost, it may decide not to do anything with their patent, possibly hoping to license some other company to make the product or it might even use their patent as a way of stopping anyone else doing it.
The interesting thing about the Merck patent is that it actually mentions "impending muscle pain" as if it's a forgone conclusion. They also discuss where they are going to obtain the CoQ10 because even in 1990 it was available.
There are several countries that prescribe CoQ10 along with statins and Japan uses CoQ10 widely, especially for people who have had cardio vascular events.
In my case I found it difficult to find a suitable dose, my GP couldn't tell me because it wasn't something she could prescribe and I didn't find any relief in the side effects of statins, possibly because I didn't take enough or, as I have read, there is a question over absorption. My wife took great pleasure in recommending an alternative way of taking CoQ10 with guaranteed absorption, and that's up the backside.
