Parke-Davis is a subsidiary of the pharmaceutical company Pfizer. Parke-Davis was acquired by Warner-Lambert in 1970, which in turn was bought by Pfizer in 2000. In 2000, Pfizer acquired Warner-Lambert, bringing together two of the fastest-growing companies in the pharmaceutical industry and adding to Pfizer's global strengths and rich heritage. With Warner-Lambert, Pfizer gained product lines ranging from Parke-Davis branded pharmaceuticals to Listerine mouthwash to Schick and Wilkinson Sword wet-shave products. 1970 also saw the deal that transformed Warner-Lambert: the acquisition of Parke-Davis, once the world's largest drugmaker. Parke-Davis traces its history back to 1866, when Hervey Parke and George Davis formed a small company in Detroit, Michigan. They pioneered the standardization of medications and built the first modern pharmaceutical laboratory. They also developed the first organized, systematic method of clinically testing new drugs. In the first half of the 20th Century, Parke-Davis introduced a number of breakthrough products, including the first bacterial vaccine, a pure form of adrenaline, and Dilantin® (phenytoin), the first widely available treatment for epilepsy and seizure. Dilantin® remains a valuable therapy against convulsions. After World War II, Parke-Davis popularized a number of anti-infectives, developed the Salk polio vaccine for widespread use, and introduced a new line of oral contraceptives. In 1976, the acquisition of Parke-Davis was approved by the United States Government and in the mid-1980s, Warner-Lambert refocused on three main businesses: prescription pharmaceuticals, consumer health care products, and gums and mints. The company grew with the introduction, in the early 1980s, of the first effective cholesterol-lowering agent, Lopid. In 1996, when Warner-Lambert entered into a co-marketing agreement with Pfizer on Lipitor® (atorvastatin calcium), a new entry into the statin class of lipid-lowering agents. Discovered by Parke-Davis Research and introduced in 1997, Lipitor® is the largest-selling pharmaceutical of any kind worldwide.