As used in this part:

(a) Anhydrous glycerin. An ingredient that may be prepared by heating glycerin U.S.P. at 150 °C for 2 hours to drive off the moisture content.

(b) Earwax removal aid. A drug used in the external ear canal that aids in the removal of excessive earwax.

(c) Water-clogged ears. The retention of water in the external ear canal, thereby causing discomfort and a sensation of fullness or hearing impairment.

(d) Ear drying aid. A drug used in the external ear canal to help dry water-clogged ears.