They will alter the chemical slightly, claiming it increases potency or solubility, patent it and then make billions. Assuming, of course, there is something to this.
A good example: Prilosec=Omeprazole, Merek was making 11 million/day on it when the patent was to expire. They brought out Nexium=Esomeprazole and claimed it to be better. Omeprazole was the first in the class, little was known about it. Originally it was approved for 20mg/day, no more than 6 weeks. It was learned to be realatively safe over time. Nexium has a recommended dose of 40mg/day, it should work better. Trust me, drug companies know how to work the system.
As someone who suffered from acid reflux let me be the first to say that I'm very happy the drug companies know how to work the system. Nexium not only controls my reflux better than Prilosec, it also repaired the significant amount of damage done to my throat by the reflux. I'm no longer a candidate for throat cancer thanks to this treatment. You criticize them for attempting to protect patents for drugs that cost them $800 million to develop and that the FDA slow plays. However, you and your children better hope the drug industry remains as profitable as possible. The U.S. is the last country where they can still make the money necessary to fund their massive R&D expenditures. Ninety percent of all new drugs are discovered in the U.S. There's a very good reason for that.
OK. So when does the patent run out on Prevacid?