A local drug manufacturer has disclosed its clinical test results for 'Zydena', the first-ever Korean-made impotency drug.

Donga Pharmaceutical Co. announced the results Tuesday at an international "men's science" seminar, adding that the product will likely make its market debut in mid-August.

Zydena is only the fourth in a line of international drugs to treat erectile dysfunction, following precedents such as Pfizer's Viagra.

Its market rollout is expected to trigger competition in Korea between domestic and foreign brands of impotency drugs. The local market is currently awash in imported products.