Choosing Topical Drug Candidate: Historical Overview

Historically most topical drug classes seem to have been originally developed following the pragmatic principle that, “if an existing drug with an interesting pharmacology is effective orally/systemically, and the target is in the skin, it could well work topically without giving side effects and, therefore, would deserve to be tried topically”. The next paragraphs review the development of the “first in their class” topical drugs. Most of the major classes of topical drugs are reviewed with the aim of understanding how the first molecule of each class was selected.