Orally dissolving melatonin formulation with acidifying agent that renders melatonin soluble in saliva

1. A composition comprising a pharmaceutical dosage form configured to disintegrate in oral saliva and maintain a pH of 4 or less within the saliva during the time the dosage form is dissolving therein, the dosage form including a therapeutically effective amount of melatonin in a carrier matrix, a disintegrant, and a sufficient amount of acid to impart the pH to the saliva, the amount of disintegrant being sufficient to cause the dosage form to completely disintegrate in the saliva, wherein the dosage form is at least one of a sublingual tablet and a buccal tablet within ten minutes from contacting the saliva.

2. The composition of claim 1 , wherein the dosage form is at least 20% w/w of the acid.

3. The composition of claim 1 , wherein the dosage form is a buccal tablet, that is at least 6% w/w disintegrant.

4. The composition of claim 1 , wherein the dosage form is a sublingual tablet, that is at least 15% w/w disintegrant.

5. The composition of claim 1 , wherein the therapeutically effective amount of melatonin is 0.2 mg to 20 mg.

6. The composition of claim 1 , wherein the dosage form is a tablet and the carrier matrix includes microcrystalline cellulose in at least 45% w/w of the dosage form, the acid in at least 20% w/w of the dosage form, and the disintegrant in at least 6% w/w of the dosage form.

7. The composition of claim 1 , wherein the acid is a carboxylic acid.

8. The composition of claim 1 , wherein the acid is citric acid.

9. The composition of claim 1 , wherein the amount of disintegrant is sufficient to cause the dosage form to completely disintegrate in the saliva within 2 minutes from contacting the saliva.

10. The composition of claim 1 , wherein the amount of disintegrant is sufficient to cause the dosage form to completely disintegrate in the saliva within 1 minute from contacting the saliva.

11. A method comprising administering a composition comprising a pharmaceutical dosage form to a subject in need thereof, the pharmaceutical dosage form dissolving in the subject's saliva while maintaining a pH of 4 or less within the saliva during the time the dosage form is dissolving, the dosage form including a therapeutically effective amount of melatonin in a carrier matrix, a disintegrant, and a sufficient amount of acid to impart the pH to the saliva, the amount of disintegrant being sufficient to cause the dosage form to completely disintegrate in the saliva within ten minutes from contacting the saliva, wherein the dosage form is at least one of a sublingual tablet and a buccal tablet.

12. The method of claim 11 , wherein the dosage form is at least 20% w/w of the acid.

13. The method of claim 11 , wherein the dosage form is a buccal tablet, that is at least 6% w/w disintegrant.

14. The method of claim 11 , wherein the dosage form is a sublingual tablet, that is at least 15% w/w disintegrant.

15. The method of claim 11 , wherein the therapeutically effective amount of melatonin is 0.2 mg to 20 mg.

16. The method of claim 11 , wherein the carrier matrix includes microcrystalline cellulose in at least 45% w/w of the dosage form, the acid in at least 20% w/w of the dosage form, and the disintegrant in at least 6% w/w of the dosage form.

17. The method of claim 11 , wherein administering occurs within 30 minutes of the time the subject desires to fall asleep.

18. The method of claim 11 , wherein administering occurs at night after the subject has awoken from sleep and desires to fall back asleep.

19. The method of claim 11 , wherein the acid is a carboxylic acid.

20. The method of claim 11 , wherein the acid is citric acid.

21. The method of claim 11 , wherein the amount of disintegrant is sufficient to cause the dosage form to completely disintegrate in the saliva within 2 minutes from contacting the saliva.

22. The method of claim 11 , wherein the amount of disintegrant is sufficient to cause the dosage form to completely disintegrate in the saliva within 1 minute from contacting the saliva.

23. A composition comprising:

a pharmaceutical dosage form configured to disintegrate in saliva and maintain a pH of 4 or less within the saliva during the time the dosage form is dissolving therein, the dosage form including:

2% w/w to 20% w/w melatonin in a therapeutically effective amount;

a carrier matrix including 45% w/w to 68% w/w filler, 6% w/w to 20% w/w disintegrant, the amount of disintegrant being sufficient to cause the dosage form to completely disintegrate in the saliva within ten minutes from contacting the saliva; and

20% w/w to 30% w/w acid, the amount of acid being effective to impart the pH to the saliva, wherein the dosage form is at least one of a sublingual tablet and a buccal tablet.

24. The composition of claim 23 , wherein the disintegrant includes crospovidone, the filler includes microcrystalline cellulose, and the acid includes citric acid.

25. The composition of claim 23 , wherein the dosage form is a sublingual tablet and the disintegrant is present in at least 15% w/w of the dosage form.

26. The composition of claim 23 , wherein the therapeutically effective amount of melatonin is 0.2 mg to 20 mg.

27. The composition of claim 23 , wherein the acid is a carboxylic acid.

28. The composition of claim 23 , wherein the acid is citric acid.

29. The composition of claim 23 , wherein the amount of disintegrant is sufficient to cause the dosage form to completely disintegrate in the saliva within 2 minutes from contacting the saliva.

30. The composition of claim 23 , wherein the amount of disintegrant is sufficient to cause the dosage form to completely disintegrate in the saliva within 1 minute from contacting the saliva.