Drug-maker Biovail has won tentative approval from the U.S. Food and Drug Administration for its immediate-release version of a zolpidem tartrate drug to combat insomnia.

The drug is currently marketed in the U.S. as Ambien and is sold by Sanofi-Aventis. Its patent doesn't expire until October 2006 and Biovail said it didn't expect final FDA approval until the expiry of the Sanofi-Aventis patent.

Biovail (TSX:BVF) said its version is easier for people to take because it dissolves in the mouth so doesn't need to be swallowed.

"Given that insomnia tends to occur more frequently in patients over the age of 60, we believe that our ODT [oral disintegrating tablet] version of zolpidem tartrate will provide health-care practitioners, upon final approval, with another viable treatment option to treat transient and intermittent sleep difficulties," Biovail CEO Douglas Squires said in a statement.

Biovail said research shows that up to 40 per cent of adults have had trouble swallowing tablets. Its new formulation of zolpidem is the first to use its easy-to-take formulation, which it is marketing as Ceform.

Zolpidem drugs currently generate about $2 billion a year in sales. Biovail said it expects to sign on with a strategic partner to market and distribute its zolpidem drug in the U.S., but hopes to do all the manufacturing of the drug itself.

Biovail shares gained 3 cents to finish at $20.02 on the TSX.