Nelson Research & Development Co., an Irvine...

Nelson Research & Development Co., an Irvine drug research concern, announced Tuesday that its joint-venture company with Sumitomo Corp., one of Japan’s leading trading companies, has opened in Tokyo.

The new company, Nelson-Sumisho, is responsible for developing and marketing products using Azone, a patented Nelson Research product, in Japan.

Azone, which is applied to the skin, temporarily makes that area more porous and speeds up the penetration of drugs through the skin.

Nelson Research holds a controlling interest in the joint-venture company, which was created last fall.