[Code of Federal Regulations] [Title 21, Volume 5] [Revised as of April 1, 2006] From the U.S. Government Printing Office via GPO Access [CITE: 21CFR358.303] [Page 310-311] 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 D_Ingrown Toenail Relief Drug Products Sec. 358.303 Definitions. As used in this subpart: (a) Ingrown toenail relief drug product. A drug product applied to an ingrown toenail that relieves pain or discomfort either by softening the nail or by hardening the nail bed. (b) Retainer ring. A die cut polyethylene foam pad coated on one side with medical grade acrylic pressure- [[Page 311]] sensitive adhesive. The retainer ring has slots, center-cut completely through the foam with the cut of sufficient size to allow for localization of an active ingredient in a gel vehicle to a specific target area. The retainer ring is used with adhesive bandage strips to place over the retainer ring to hold it in place.