This also includes the interesting area of drugs which are already been patented and licensed but find new uses once out of patent for different conditions, Nal

This also includes the interesting area of drugs which are already been patented and licensed but find new uses once out of patent for different conditions, Naltrexone being a prime example. google Dr Ian Zagon's work at Penn State if you are interested in his work on Naltrexone, OGF and opiod receptors generally.