Japan-based Eisai has signed a joint research agreement with Nitto Denko to develop a transdermal formulation of Aricept, an agent for treating Alzheimer's disease.

Aricept, currently available in pill form, is a type of drug known as a cholinesterase inhibitor. It is one of a group of medications that appear to improve the cognitive ability (thinking, perception, judgment and recognition) in people with Alzheimer's disease.

The medication has been shown to be most effective in the early stages of the disease, the company reported.