Editing Sildenafil (section)

====South Korea====
In 1999 South Korea granted two patents to Pfizer related to sildenafil. The first document guaranteed sole production and sale of the substance until 2012, while the second gave Pfizer the exclusive use to treating erectile dysfunction with sildenafil until 2014.<ref>{{Cite web|date=14 March 2012|title=Generic Viagra developers queue up, but may have to wait|url=http://www.koreaherald.com/view.php?ud=20120314001093|access-date=28 December 2021|website=The Korea Herald|archive-date=28 December 2021|archive-url=https://web.archive.org/web/20211228061652/http://www.koreaherald.com/view.php?ud=20120314001093|url-status=live}}</ref> In 2011 [[Hanmi Pharmaceutical]] and [[CJ CheilJedang]] launched a suit against the exclusive use patent. The Korean Court system made a ruling against Pfizer in June 2012, allowing for the unhindered domestic production of generic prescription sildenafil.<ref>{{Cite news|date=1 June 2012|title=Approved Viagra copies flood drugstores in Korea|work=Reuters|url=https://www.reuters.com/article/us-korea-viagra-idUSBRE8500KF20120601|access-date=28 December 2021|archive-date=28 December 2021|archive-url=https://web.archive.org/web/20211228061651/https://www.reuters.com/article/us-korea-viagra-idUSBRE8500KF20120601|url-status=live}}</ref>

During 2012 Viagra lost its position as the top selling erectile dysfunction treatment in South Korea. This development was credited largely "due to the introduction of generic products." Generic sildenafil became publicly available in May. Sales of PalPal by Hanmi Pharmaceuticals totalled ₩22 billion or about 86% the market share of Viagra that year.<ref>{{Cite web|date=10 April 2013|title=Viagra loses top spot in Korean market|url=http://www.koreaherald.com/view.php?ud=20130410000803|access-date=28 December 2021|website=The Korea Herald|archive-date=28 December 2021|archive-url=https://web.archive.org/web/20211228061651/http://www.koreaherald.com/view.php?ud=20130410000803|url-status=live}}</ref> By 2017 there were over 50 generic sildenafil pills available. During that year Viagra sales slumped to 38% that of Palpal.<ref>{{Cite web|date=12 December 2017|title=Hanmi leads erectile dysfunction drug sales|url=http://www.koreabiomed.com/news/articleView.html?idxno=2104|access-date=28 December 2021|website=KBR|language=ko|archive-date=28 December 2021|archive-url=https://web.archive.org/web/20211228061652/http://www.koreabiomed.com/news/articleView.html?idxno=2104|url-status=live}}</ref>