[Code of Federal Regulations] [Title 21, Volume 5] [Revised as of April 1, 2008] From the U.S. Government Printing Office via GPO Access [CITE: 21CFR349.18] [Page 284] TITLE 21--FOOD AND DRUGS CHAPTER I--FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF PART 349_OPHTHALMIC DRUG PRODUCTS FOR OVER-THE-COUNTER HUMAN USE--Table of Contents Subpart B_Active Ingredients Sec. 349.18 Ophthalmic vasoconstrictors. The active ingredient of the product consists of one of the following, within the established concentration for each ingredient: (a) Ephedrine hydrochloride, 0.123 percent. (b) Naphazoline hydrochloride, 0.01 to 0.03 percent. (c) Phenylephrine hydrochloride, 0.08 to 0.2 percent. (d) Tetrahydrozoline hydrochloride, 0.01 to 0.05 percent.