Use of cooling agents to relieve mild ocular irritation and enhance comfort
Ophthalmic compositions containing very low concentrations (e.g., 1 to 50 ppm) of cooling agents are described. The cooling agents are less volatile and less prone to causing ocular discomfort than agents previously utilized to obtain an ocular cooling effect, such as menthol. The cooling agents are preferably contained in a vehicle that forms a gel or partial gel upon application to the eye.
1 . An ophthalmic composition containing a cooling effective amount of a cooling agent selected from the group consisting of menthyl esters, carboxamides, menthane glycerol ketals, alkyl substituted ureas, sulfonamides, terpene analogs, furanones, phosphine oxides, and combinations thereof; and an ophthalmically acceptable vehicle therefor.
2 . A composition according to claim 1 , wherein the concentration of the cooling agent is 1 to 50 ppm.
3 . A composition according to claim 2 , wherein the cooling agent is selected from the group consisting of N,2,3-Trimethyl-2-isopropylbutamide and N-ethyl-5-methyl-2-(1-methylethyl), and combinations thereof.
4 . A composition according to claim 1 , wherein the vehicle comprises an aqueous solution that forms a gel or partial gel upon application to the eye.
5 . A composition according to claim 4 , wherein the aqueous solution contains a galactomannan polymer.
6 . A composition according to claim 5 , wherein the galactomannan polymer comprises guar or a derivative thereof.