Movie Question

Years ago, I saw a movie in which a horror makeup specialist was the villain. He had worked on - and with - the greats, but now the studio was switching to teen beach films and he was out of a job, once this last monster movie was over.

He had discovered that by adding a drug to his effects makeup he could produce a hypnotic effect. He used this to cause the young actors in the movie - in full makeup - to murder the executives responsible for the change in genre.

Can anyone tell me the name of this movie?