After patent protection expires, active pharmaceutical ingredients may be manufactured and marketed by other companies as so-called generics or imitation products. Pharmaceutical companies patent newly developed active pharmaceutical ingredients. Patent protection gives the patent holder the sole right to manufacture and market the active ingredient.
If patent protection expires, other companies can also produce this active ingredient and sell it under a different name. Such a preparation is called an imitation product or generic drug (plural: generics). Generics are usually cheaper than the originals because the manufacturer did not have to conduct its own research, but benefits from the expired patent protection for a proven drug. Generics are also tested by the responsible authorities according to strict criteria before they are approved.