Why are brand-name medicines more expensive than generic medicines?

Once the brand-name medicine has undergone research and development, which is very costly and time consuming, the pharmaceutical manufacturer applies for a license and registers a patent in respect of the medicine developed. This patent gives the pharmaceutical manufacturer exclusive rights to market the product to the public for a certain length of time. When the patent expires, other pharmaceutical manufacturers may produce the same medicine under a different name, called a generic. The generic medicine is less costly because it does not have to undergo the same expensive research and development.