21 CFR § 358.103 - Definitions.

---
identifier: "/us/cfr/t21/s358.103"
source: "ecfr"
legal_status: "authoritative_unofficial"
title: "21 CFR § 358.103 - Definitions."
title_number: 21
title_name: "Food and Drugs"
section_number: "358.103"
section_name: "Definitions."
chapter_name: "FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES"
subchapter_number: "D"
subchapter_name: "DRUGS FOR HUMAN USE"
part_number: "358"
part_name: "MISCELLANEOUS EXTERNAL DRUG PRODUCTS FOR OVER-THE-COUNTER HUMAN USE"
positive_law: false
currency: "2026-04-05"
last_updated: "2026-04-05"
format_version: "1.1.0"
generator: "[email protected]"
authority: "21 U.S.C. 321, 351, 352, 353, 355, 360, 371."
regulatory_source: "55 FR 33255, Aug. 14, 1990, unless otherwise noted."
cfr_part: "358"
---


# 358.103 Definitions.

As used in this subpart:

(a) *Wart remover drug product.* A topical agent used for the removal of common or plantar warts.

(b) *Collodion-like vehicle.* A solution containing pyroxylin (nitrocellulose) in an appropriate nonaqueous solvent that leaves a transparent cohesive film when applied to the skin in a thin layer.

(c) *Plaster vehicle.* A fabric, plastic, or other suitable backing material in which medication is usually incorporated for topical application to the skin.