All Gummed Up (1947)

The Stooges run a drug store and are about to have their lease taken away by Amos Flint, the mean old man who owns the place. When Flint kicks his wife out for being too old, the Stooges try to help her by inventing a formula that makes old people young. Their concoction turns the wife into a beautiful young woman, and Flint offers the boys the store for free if they'll transform him as well. They agree, but after he swallows the stuff he turns into an infant, and the boys leave on the run.