[Code of Federal Regulations] [Title 21, Volume 5] [Revised as of April 1, 2001] From the U.S. Government Printing Office via GPO Access [CITE: 21CFR358.503] [Page 295] TITLE 21--FOOD AND DRUGS CHAPTER I--FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES--Continued PART 358--MISCELLANEOUS EXTERNAL DRUG PRODUCTS FOR OVER-THE-COUNTER HUMAN USE--Table of Contents Subpart F--Corn and Callus Remover Drug Products Sec. 358.503 Definitions. As used in this subpart: (a) Corn and callus remover drug product. A topical agent used for the removal of corns and calluses. (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.