Compositions and Methods for Eye Whitening
The invention provides compositions and methods for whitening of eyes and/or reducing redness of eyes. The provided compositions and methods utilize low concentrations of selective α-2 adrenergic receptor agonists. The compositions preferably include brimonidine, dexmedetomidine, guanfacine or fadolmidine.
1 . A method of increasing whiteness of an eye comprising administering to a subject in need thereof a composition comprising a selective α-2 adrenergic receptor agonist having a binding affinity of 300 fold or greater for α-2 over α-1 adrenergic receptors, or a pharmaceutically acceptable salt thereof.
2 . The method of claim 1 , wherein said selective α-2 adrenergic receptor agonist has a binding affinity of 500 fold or greater for α-2 over α-1 adrenergic receptor.
3 . The method of claim 1 , wherein said selective α-2 adrenergic receptor agonist is selected from the group consisting of brimonidine, alpha methyl dopa, guanfacine, fadolmidine, dexmedetomidine, (+)-(S)-4-[1-(2,3-dimethyl-phenyl)-ethyl]-1,3-dihydro-imidazole-2-thione, 1-[(imidazolidin-2-yl)imino]indazole, and mixtures of these compounds.
4 . The method of claim 1 , wherein said α-2 adrenergic receptor agonist is present at a concentration from about 0.001% to about 0.06% weight by volume.
5 . The method of claim 1 , wherein said α-2 adrenergic receptor agonist is dexmedetomidine at a concentration from about 0.01% to about 0.060% weight by volume.
6 . The method of claim 1 , wherein said α-2 adrenergic receptor agonist is guanfacine at a concentration from about 0.01% to about 0.028% weight by volume.
7 . The method of claim 1 , wherein said α-2 adrenergic receptor agonist is fadolmidine at a concentration from about 0.01% to about 0.025% weight by volume.
8 . The method of claim 1 , further comprising from about 0.005% to 0.01% weight by volume of calcium chloride.
9 . A method of reducing redness of an eye comprising administering to a subject in need thereof a composition comprising a selective α-2 adrenergic receptor agonist having a binding affinity of 300 fold or greater for α-2 over α-1 adrenergic receptors, or a pharmaceutically acceptable salt thereof.
10 . The method of claim 9 , wherein said selective α-2 adrenergic receptor agonist has a binding affinity of 500 fold or greater for α-2 over α-1 adrenergic receptor.
11 . The method of claim 9 , wherein said selective α-2 adrenergic receptor agonist is selected from the group consisting of brimonidine, alpha methyl dopa, guanfacine, fadolmidine, dexmedetomidine, (+)-(S)-4-[1-(2,3-dimethyl-phenyl)-ethyl]-1,3-dihydro-imidazole-2-thione, 1-[(imidazolidin-2-yl)imino]indazole, and mixtures of these compounds.
12 . The method of claim 9 , wherein said α-2 adrenergic receptor agonist is present at a concentration from about 0.001% to about 0.06% weight by volume.
13 . The method of claim 9 , wherein said α-2 adrenergic receptor agonist is dexmedetomidine at a concentration from about 0.01% to about 0.060% weight by volume.
14 . The method of claim 9 , wherein said α-2 adrenergic receptor agonist is guanfacine at a concentration from about 0.01% to about 0.038% weight by volume.
15 . The method of claim 9 , wherein said α-2 adrenergic receptor agonist is fadolmidine at a concentration from about 0.01% to about 0.025% weight by volume.
16 . The method of claim 9 , further comprising from about 0.005% to 0.01% weight by volume of calcium chloride.
17 . A method of reducing redness of an eye while simultaneously increasing whiteness of the eye comprising administering to a subject in need thereof a composition comprising a selective α-2 adrenergic receptor agonist having a binding affinity of 300 fold or greater for α-2 over α-1 adrenergic receptors, or a pharmaceutically acceptable salt thereof.
18 . The method of claim 17 , wherein said selective α-2 adrenergic receptor agonist has a binding affinity of 500 fold or greater for α-2 over α-1 adrenergic receptor.
19 . The method of claim 17 , wherein said selective α-2 adrenergic receptor agonist is selected from the group consisting of brimonidine, alpha methyl dopa, guanfacine, fadolmidine, dexmedetomidine, (+)-(S)-4-[1-(2,3-dimethyl-phenyl)-ethyl]-1,3-dihydro-imidazole-2-thione, 1-[(imidazolidin-2-yl)imino]indazole, and mixtures of these compounds.
20 . The method of claim 17 , wherein said α-2 adrenergic receptor agonist is present at a concentration from about 0.001% to about 0.06% weight by volume.
21 . The method of claim 1 , wherein the composition further comprises a cyclodextrin.
22 . The method of claim 21 wherein the cyclodextrin is 2 hydroxypropyl beta cyclodextrin.