Someone asked a question about pharmacy formularies, and I searched for information regarding regulation. I assumed FDA would regulate these things, and in my search for that information on the fda site, I ran across the info for clinical trials. Those are just the clinical trials for cf, there are many many others.
I never did find any information about whether or not pharmacies can alter the price, or move the medication onto their 'prefered' list. I know it happened to me at the beginning of this year. I started paying some really odd prices for things, rather than the typical established amount. Turned out, the plan had indeed changed, and they went to a percentage co-pay on anything that is on the 'prefered' list (you know, the list of the items we need the most, so they will charge us more for - yeah that list.)