tl;dr: No, you didn't miss anything. Nothing is ever mentioned in either series about why Dr. Wells wasn't tempted by the Mirakuru -- either as a villain, or even just as a very curious scientist. (But, read on for some reasoned speculation)
Without a direct explanation on-screen, the best we can do is try to figure out what might have kept Dr. Wells away. I can think of three good reasons, any combination of which would explain his lack of interest in the drug:
Nasty Side Effects
It's possible that Dr. Wells might be passingly familiar with Mirakuru from his "research". Given how extensively he studied the life and history of The Flash, who it seems is destined to form a Justice League w/ Green Arrow and others, he may have run across stories about Deathstroke and what happened to him. Even if he wasn't already aware of it, Felicity would certainly have warned Caitlin and Cisco how dangerous the drug is, and they would have told Dr. Wells the same.
Dr. Wells considers himself a very smart person, and prides himself on being able to outsmart everyone around him. He's probably not going to be very eager to take a drug that's going to compromise him mentally and emotionally, since that's completely counter to his usual style.
Not Enough Sample
It's also possible that the sample Oliver provided wasn't big enough to both make a cure and use on a human subject. We already know that STAR Labs used the entire sample up in making the cure, though we don't know if they made any effort to keep any. From a forensic chemistry perspective, this probably meant putting portions of the sample through devices like mass spectrometers, which break down an unknown substance into known parts. These devices usually destroy the source sample in the process. (For example, a GC/MS vaporizes a substance and measures various aspect of the the constituent components.)
So, if there was only a small sample of the drug, and analyzing it destroyed it, there may not have been enough left to have any effect on someone. As part of his cover identity, Dr. Wells certainly wouldn't jeopardize his team's ability to formulate a cure, so he would have to let them destroy the sample.
Better Things To Do
Over the course of the season, we've seen that Cisco and Caitlin occasionally do independent work at the labs. Dr. Wells usually finds out about these side projects through simple curiosity -- he sees them doing something and asks questions. Obviously, since they work for him, they can't actively keep this kind of project secret.
But remember, the showdown with Deathstroke was happening while Barry was still in a coma, and STAR Labs had just had a major catastrophe. Dr. Wells probably had many other issues to deal with, between the PR nightmare, trying to keep the lab operational, and trying to weasel his was into Barry's life.
The STAR Labs team may not have seen any reason to involve Wells in what they were doing, especially if they didn't think he would object and didn't need his assistance. They may simple have managed to work up the Mirakuru cure without Wells even knowing about it.
