In the majority of cases, the grant of a patent captures the chemistry and purpose of a drug and locks it away for the given number of years. This is the monopoly given to the manufacturer who will police the drug market and sue anyone who comes too close for infringing the patent. The very act of protection discourages future research to develop the drug for new and different purposes. Yet, in one or two cases, research does go on. Most of the time, this represent unofficial interests where physicians experiment with off-label uses, or there is just a simple change so that, what comes in multiple doses, may be spread out through an extended release