Opioid addition is a serious problem in this country. But there are two drugs which fairly effectively block opioid addiction, methadone and buprenorphine. Both of these drugs are also subject to widespread abuse. In fact, buprenorphine is the single most abused drug in the nation's prisons.
Titan Pharmaceuticals came up with the idea of making buprenorphine essentially non-abusable by changing its method of administration. Instead of using daily pills or sublingual dissolving "pads," Titan came up with making little, implantable tubes loaded with buphrenorphine, like Norplant. (Norplant is an implantable contraceptive in wide use throughout the world, except in the U.S.) The little tubes have to be inserted by a physican, since they go deep under the skin. They're not removable except by a doctor. They last for about six months, then they have to be replaced.
Titam's delivery system, which they call Probuphine, seems to be a slam-dunk. The drug itself is effective and has been used to control opioid addiction for 15 years. The delivery method has been in use for over 50 years and has a good record.
Titan expensively jumped through all the FDA hoops: phases Ia and Ib, II, IIIa and IIIb. The advisory committee overwhelmingly approved it, with a vote of something like 19-4.
The FDA bounced it.
Titan was pretty much out of money, so they had to partner with another firm, Braeburn, which demanded and got a huge chunk of potential Probuphine revenue, should it pass.
So, Titan and Braeburn then brewed up another test protocol, with kibbitzing by the FDA. The test successfully met all goals, and had another advisory committee hearing. Once again Probuphine passed by an overwhelming majority.
Months and months later, Titan is still waiting for the FDA to rule.
This is what any hardware or eliquid PMTA faces. Or worse.