Ophthalmic compositions comprising a dipeptide

1. An aqueous ophthalmic composition comprising one or more antimicrobial components selected from the group consisting of 0.2 ppm to 3 ppm poly(hexamethylene biguanide), from 0.5 ppm to 5 ppm α-[4-tris(2-hydroxyethyl)-ammonium chloride-2-butenyl]poly[1-dimethyl ammonium chloride-2-butenyl]-ω-tris(2-hydroxyethyl) ammonium chloride and alexidine, and a dipeptide, wherein the dipeptide comprises a glycine moiety and another amino acid moiety other than glycine, and the dipeptide is present in an amount to enhance the biocidal efficacy of the ophthalmic composition.

2. The ophthalmic composition according to claim 1 , wherein the amount of the dipeptide further functions as a buffer in the physiological pH range.

3. The ophthalmic composition according to claim 1 , wherein the dipeptide is selected from the group consisting of N-glycylserine and N-glycylhistidine.

4. The ophthalmic composition according to claim 1 , wherein the dipeptide is present from 0.1 wt. % to 1.0 wt. %.

5. An ophthalmic composition comprising:

a dipeptide comprising a glycine moiety and another amino acid moiety other than glycine, wherein the dipeptide is present in an amount to enhance the biocidal efficacy of the ophthalmic composition;

an antimicrobial component selected from the group consisting of biguanides, polymeric biguanides, quaternium ammonium compounds and any one mixture thereof; and

0.005 wt. % to 0.8 wt. % of a comfort agent selected from the group consisting of hyaluronic acid, hydroxypropylmethyl cellulose, hydroxyethyl cellulose, dexpanthenol, sorbitol, propylene glycol and hydroxypropyl guar.

6. The ophthalmic composition of claim 5 further comprising

0.05 wt. % to 1 wt. % of an amphoteric surfactant of general formula I

wherein R 1 is R or −(CH 2 ) n —NHC(O)R, wherein R is a C 8 -C 30 alkyl optionally substituted with hydroxyl and n is 2, 3 or 4; R 2 and R 3 are each independently selected from the group consisting of hydrogen and C 1 -C 4 alkyl; R 4 is a C 2 -C 8 alkylene optionally substituted with hydroxyl; and Y is CO 2 − or SO 3 − .

7. The composition of claim 5 wherein the comfort agent is hyaluronic acid, which is present from 0.005 wt. % to 0.04 wt. %, and the antimicrobial component includes 0.3 ppm to 2.0 ppm of poly(hexamethylene biguanide).

8. The composition of claim 6 wherein R 1 is R; R 2 and R 3 are each independently selected from a C 1 -C 2 alkyl; R 4 is a C 2 -C 4 alkylene and Y is SO 3 − .

9. The composition of claim 5 wherein the antimicrobial component is α-[4-tris(2-hydroxyethyl)-ammonium chloride-2-butenyl]poly[1-dimethyl ammonium chloride-2-butenyl]-ω-tris(2-hydroxyethyl) ammonium chloride, which is present from 0.5 ppm to 15 ppm.

10. The composition of claim 5 further comprising 0.01 wt. % to 0.05 wt. % ethylenediaminetetraacetic acid or a corresponding salt thereof.

11. The composition of claim 5 wherein the comfort agent is propylene glycol, sorbitol or hydroxypropylmethyl cellulose.

12. The composition of claim 5 wherein the comfort agent is hydroxypropyl guar.

13. The ophthalmic composition of claim 5 further comprising a poloxamine with an HLB value from 13 to 28.

14. A method of cleaning and disinfecting a contact lens, the method comprising soaking the contact lens in the ophthalmic composition of claim 5 for at least two hours.

15. The method of claim 14 further comprising inserting the cleaned and disinfected contact lens into the eye without rinsing the lens after soaking.

16. The method of claim 14 further comprising rinsing the cleaned and disinfected contact lens with the composition of claim 5 prior to inserting the lens into the eye.