The following combinations are permitted provided each active ingredient is present within the established concentration, and the product is labeled in accordance with §349.79.

(a) Any single ophthalmic astringent active ingredient identified in §349.10 may be combined with any single ophthalmic vasoconstrictor active ingredient identified in §349.18.

(b) Any two or three ophthalmic demulcent active ingredients identified in §349.12 may be combined.

(c) Any single ophthalmic demulcent active ingredient identified in §349.12 or any ophthalmic demulcent combination identified in paragraph (b) of this section may be combined with any single ophthalmic vasoconstrictor identified in §349.18.

(d) Any single ophthalmic astringent active ingredient identified in §349.10 may be combined with any single ophthalmic vasoconstrictor active ingredient identified in §349.18 and any single ophthalmic demulcent identified in §349.12 or ophthalmic demulcent combination identified in paragraph (b) of this section.

(e) Any two or more emollient active ingredients identified in §349.14 may be combined as necessary to give the product proper consistency for application to the eye.