When a new medication is first introduced, it always has two names. The generic name is the name of the chemical in the tablet and is the same the world over. The brand name is the name given by the manufacturer and is normally patented. Thus any one drug can only have one generic name (such as verapamil), but may have several brand names. This may be either because it is sold by different manufacturers (verapamil is sold by Knoll as Isoptin, and by Searle as Calan), or because it is made up in different formulations (Searle has recently introduced Covera, which is a timed-release form of verapamil). When the manufacturer's patent runs out, the drug becomes available in its generic form, in which case, there will be no brand name on the bottle.