DULUTH — The owner of a Duluth store that sells synthetic drugs is suing the city over a new ordinance regulating the product.

Last Place on Earth owner Jim Carlson said the ordinance passed by the City Council last month is unconstitutional. It requires retailers to get a license to sell synthetic drugs. Carlson is asking the court for a preliminary injunction to block the ordinance from taking effect.

Carlson has filed at least one other lawsuit against the city after police raided his store. He alleged some items were seized illegally. That lawsuit has been dismissed.