21 CFR § 346.3 - Definitions.
As used in this part:
(a) Analgesic, anesthetic drug. A topically (externally) applied drug that relieves pain by depressing cutaneous sensory receptors.
(b) Anorectal drug. A drug that is used to relieve symptoms caused by anorectal disorders in the anal canal, perianal area, and/or the lower rectal areas.
(c) Antipruritic drug. A topically (externally) applied drug that relieves itching by depressing cutaneous sensory receptors.
(d) Astringent drug. A drug that is applied topically (externally) to the skin or mucous membranes for a local and limited protein coagulant effect.
(g) Keratolytic drug. A drug that causes desquamation (loosening) and debridement or sloughing of the surface cells of the epidermis.
(h) Local anesthetic drug. A drug that produces local disappearance of pain, burning, itching, irritation, and/or discomfort by reversibly blocking nerve conduction when applied to nerve tissue in appropriate concentrations.
(i) Protectant drug. A drug that provides a physical barrier, forming a protective coating over skin or mucous membranes.
(j) Vasoconstrictor. A drug that causes temporary constriction of blood vessels.