South Korean pharmaceutical firms are rushing out generic Viagra copies with names like "Nurigra" and "Happigra" to tap into the erectile dysfunction drug market now that a court has ruled in their favor.
 
Pfizer's patent on Viagra active ingredient sildenafil expired on May 17, since when six local companies, including CJ Cheiljedang and Hanmi Pharm, have released prescription-only generic versions.
 
A court this week ruled against Pfizer's claim that a "use patent" barred generic copies from being sold as erectile dysfunction treatments.
 
Pfizer Korea said it was "considering options for appeal" and its use patent remains valid until the result of that appeal in announced.
 
But more pharmaceutical companies are expected to release their own versions, according to a statement by patent regulator Korean Intellectual Property Office.
 
"In an aging society, people are looking to improve their quality of life and expansion of the (erectile dysfunction drug) market is part of that trend," said Shin Seoung-pill, a PR representative for CJ Cheiljedang.
 
As of Thursday, some 19 pharmaceutical firms had received approval for 37 generic Viagra copies from the Korea Food and Drug Administration.
 
Some of the released generic versions have put their own spin on the "little blue pill". Happigra comes in pill or mint-flavored powder form, says maker Samjin Pharmaceuticals. Daewoong Pharma, maker of Nurigra, made the pill triangular and green in answer to consumer suggestions that blue is too recognizable as an impotence drug.
 
Other competitors touted affordable prices. Hanmi's generic Viagra called "Pal Pal" costs 5,000 won ($4.25) per 100 mg tablet, or one-third the local over-the-counter price of Viagra, according to the company.
 
South Korea's erectile dysfunction drug market was worth 103 billion won ($87.27 million) in 2011, according to data provider IMS Health.
 
The market has grown nine percent or more every year since 2008 and companies estimate the local black market for counterfeit Viagra and other erectile dysfunction drugs matches or exceeds the legitimate market, said one product manager of a generic Viagra maker who requested anonymity.
 
The trend reflects the country's rapidly changing demographics. South Korea is currently the third youngest population in the Organization for Economic Cooperation and Development group of developed economies, but will become the second oldest by 2050, according to OECD estimates.
 
(Reporting By Jung Yoon Lee; Editing by Nick Macfie)