A pharmaceutically delivery system and method of use therefor are described comprising a pharmaceutically active agent and acidified nitrite as an agent to produce local production of nitric oxide at the skin surface. The dosage form may be in any pharmaceutically acceptable carrier means and comprises an acidifying agent adapted to reduce the pH at the environment. In one embodiment, a barrier consisting of a membrane allows diffusions of the anaesthetic and nitrite ions while preventing direct contact of the skin and acidifying agent.