If you start getting specific in your book and presenting information as factual, it will indeed have to be correct. Otherwise, your book will lose credibility. Readers who know you've presented incorrect information as facts will be upset with you, and you may lose credibility as an author. Even though you are writing fiction, it will have to sound realistic.
I don't know how to get around this, unless you have you scientist or doctor work on a combination of chemicals that are not named.
It's difficult, I know. I'm facing a similar problem and it's got me stalled in my own work. My dilemma deals with medications that have not been approved by the FDA, but have (somehow?) fallen into the hands of an evil doctor who is conducting experiments on an unsuspecting patient. Sounds simple enough, but I want my facts to be true, and I'll need to do some research on the FDA, medications, and so forth. Everything else is falling into place,but if this one part isn't right -- doesn't matter how good the writing is. I'm doomed!
Good luck with yours.