Compositions and use of varenicline for treating dry eye

1. A method of improving ocular discomfort in an individual in need thereof comprising administering a therapeutically effective amount of varenicline to the individual, wherein said administration is by locally administering a pharmaceutical formulation comprising varenicline or a pharmaceutically acceptable varenicline salt and one or more pharmaceutically acceptable inactive ingredients, wherein the concentration of varenicline in the formulation is between about 0.1 mg/mL and about 10 mg/mL, into a nasal cavity of the individual, and wherein the therapeutically effective amount of varenicline administered into the nasal cavity is between 5 micrograms and 1000 micrograms.

2. The method of claim 1 , wherein the amount of varenicline so administered selectively binds to peripheral nicotinic acetylcholine receptors.

3. The method of claim 1 , wherein the amount of varenicline so administered is between 5 micrograms and 100 micrograms.

4. The method of claim 1 , wherein the amount of varenicline so administered is between 25 micrograms and 500 micrograms.

5. The method of claim 1 , wherein the amount of varenicline so administered into the nasal cavity is between 5 micrograms and 500 micrograms.

6. The method of claim 1 , wherein the pharmaceutical formulation is a liquid, suspension, aerosol, gel, ointment, dry powder, cream, paste, lotion, or balm.

7. The method of claim 6 , wherein the pharmaceutical formulation comprises a solution of the varenicline or varenicline salt.

8. The method of claim 7 , wherein the pharmaceutical formulation is a liquid administered as a nasal spray.

9. The method of claim 1 , wherein the ocular discomfort is associated with dry eye disease or symptoms of dry eye disease.

10. The method of claim 1 , wherein the ocular discomfort is associated with symptoms of dry eye disease and wherein the improvement is measurable by recording dry eye disease symptom severity on a visual analog scale.

11. The method of claim 1 , wherein the ocular discomfort is associated with dryness or sticky feeling with dry eye disease.

12. The method of claim 1 , wherein the amount of varenicline so administered does not result in clinically significant undesired psychoactive side effects.

13. The method of claim 1 , wherein the amount of varenicline so administered does not result in clinically significant vomiting.

14. The method of claim 1 , wherein the pharmaceutical formulation comprises a phosphate buffer or a phosphate citrate buffer.

15. The method of claim 1 , wherein the pharmaceutical formulation comprises a buffer with a pH of from around 5.0 to around 7.4.

16. The method of claim 15 , wherein the pharmaceutical formulation comprises a buffer with a pH of around 5.0, around 6.0, around 7.0 or around 7.4.

17. A method of increasing tear production in an individual in need thereof comprising administering a therapeutically effective amount of varenicline to the individual, wherein said administration is by locally administering a pharmaceutical formulation comprising varenicline or a pharmaceutically acceptable varenicline salt and one or more pharmaceutically acceptable inactive ingredients, wherein the concentration of varenicline in the formulation is between about 0.1 mg/mL and about 10 mg/mL, into a nasal cavity of the individual, and wherein the therapeutically effective amount of varenicline administered into the nasal cavity is between 5 micrograms and 1000 micrograms.

18. The method of claim 17 , wherein the amount of varenicline so administered selectively binds to peripheral nicotinic acetylcholine receptors.

19. The method of claim 17 , wherein the amount of varenicline so administered is between 5 micrograms and 100 micrograms.

20. The method of claim 17 , wherein the amount of varenicline so administered is between 25 micrograms and 500 micrograms.

21. The method of claim 17 , wherein the amount of varenicline so administered is between 5 micrograms and 500 micrograms.

22. The method of claim 17 , wherein the pharmaceutical formulation is a liquid, suspension, aerosol, gel, ointment, dry powder, cream, paste, lotion, or balm.

23. The method of claim 22 , wherein the pharmaceutical formulation comprises a solution of the varenicline or varenicline salt.

24. The method of claim 23 , wherein the pharmaceutical formulation is a liquid administered as a nasal spray.

25. The method of claim 17 , wherein the tear production increases in an amount measurable by a Jones Schirmer test.

26. The method of claim 17 , wherein the pharmaceutical formulation comprises a phosphate buffer or a phosphate citrate buffer.

27. The method of claim 17 , wherein the pharmaceutical formulation comprises a buffer with a pH of from around 5.0 to around 7.4.

28. The method of claim 27 , wherein the pharmaceutical formulation comprises a buffer with a pH of around 5.0, around 6.0, around 7.0 or around 7.4.

29. The method of claim 1 , wherein the ocular discomfort is associated with symptoms of dry eye disease, and wherein the method comprises increasing tear production in the individual.

30. The method of claim 29 , wherein the tear production increases in an amount measurable by a Jones Schirmer test.