What's more, American cigarette makers embraced NTR as a business opportunity. Combined with counseling, nicotine patches, gum, lozenges, inhalers or nasal sprays - together known as NRT - came into play in 1984 as prescription medicine. In 1996, at the urging of pharmaceutical companies, the U.S. Food and Drug Administration (FDA) allowed those products to be sold over-the-counter. The tobacco industry once viewed nicotine patches and gum as a threat to their cigarette sales. However, with formerly secret internal documents known as the "Tobacco Papers," dated between 1960 and 2010 from the seven major tobacco companies operating in the United States, researchers at the University of California, San Francisco, revealed that cigarette makers had started investing in alternative forms of nicotine delivery as early as the 1950s, but stopped short because people largely regarded nicotine as harmful, and such products might have attracted the attention of FDA regulators. Published this week in the American Journal of Public Health (AJPH), the study titled "Tobacco Industry Research on Nicotine Replacement Therapy: 'If Anyone Is Going to Take Away Our Business It Should Be Us'" found that in 1987, three years after FDA first approved nicotine gum as a quitting aid, the tide had turned on the public perception of nicotine; and that by 1992, the tobacco industry had determined that patches and gum by themselves do not help smokers quit. For more than a decade, the companies did not act on this knowledge out of fear of FDA regulation. But once the federal agency started regulating cigarettes in 2009, they went all out in their bid to develop and sell NRT. The Tobacco Papers reveal that companies conjectured that their new nicotine products could successfully compete with pharmaceutical NRT and they set the goal of gaining market control of all products containing nicotine.