The very famous quote credited to Paracelsus who expressed the classic toxicology maxim that, "All things are poison, and nothing is without poison; only the dose makes a thing not a poison." The principle relies on the finding that all chemicals, even water and oxygen can be toxic if too much is eaten, drunk, or absorbed. The idea simply describes the phenomenon in which poisonous substances can be medicinal in small doses.

Drug patent expiration presents a significant opportunity for the launch of generic medications, which can dramatically alter market dynamics. When a branded drug's patent expires, it opens the door for generic manufacturers to produce and sell bioequivalent versions at a lower cost, leading to increased competition and reduced prices. This not only makes medications more accessible to patients but also creates substantial market opportunities for generic pharmaceutical companies.