Ophthalmic oil-in-water type emulsion with stable positive zeta potential

1. An ophthalmic oil-in-water submicron emulsion, which comprises colloid particles having an oily core surrounded by an interfacial film, said emulsion comprising:

1% by weight of mineral oil;

0.002% by weight of at least one cationic agent, said agent being cetalkonium halide;

0.3% by weight of tyloxapol; and

0.1% by weight of poloxamer,

wherein,

said emulsion does not contain phospholipids,

said emulsion does not contain anionic surfactants,

said emulsion has a positive zeta potential, and

said emulsion meets the zeta potential stability under thermal stress conditions as determined by Test A:

measuring zeta potential, in mV, of said emulsion at the time of preparation is Z 0 ,

sealing 5-10 ml of said emulsion in 10 ml Type I glass vials under nitrogen atmosphere without bubbling,

storing said sealed vials at 80° C. for 15 hours,

measuring zeta potential, in mV, of said emulsion at 15 hours, Z 15 ,

determining the difference between Z 15h −Z 0 , δA, wherein, the emulsion meets the zeta potential stability under thermal stress conditions according to Test A for a δA less than the standard error of zeta potential measurement.

2. The ophthalmic emulsion according to claim 1 , which meets the zeta potential stability as determined by Test B:

measuring zeta potential, in mV, of said emulsion at the time of preparation is Z 0 ,

sealing 5-10 ml of said emulsion in 10 ml Type I glass vials under nitrogen atmosphere without bubbling,

storing said sealed vials at 80° C. for 48 hours,

measuring zeta potential, in mV, of said emulsion at 48 hours, Z 2 ,

determining the difference between Z 2 −Z 0 , δA, wherein, the emulsion meets the zeta potential stability under thermal stress conditions according to Test B for a δA less than the standard error of zeta potential measurement.

3. The ophthalmic emulsion according to claim 1 , which meets the zeta potential stability as determined by Test C:

measuring zeta potential, in mV, of said emulsion at the time of preparation is Z 0 ,

sealing 5-10 ml of said emulsion in 10 ml Type I glass vials under nitrogen atmosphere without bubbling,

storing said sealed vials at 80° C. for 7 days,

measuring zeta potential, in mV, of said emulsion at 7 days, Z 7 ,

determining the difference between Z 7 −Z 0 , δA, wherein, the emulsion meets the zeta potential stability under thermal stress conditions according to Test C for a δA less than the standard error of zeta potential measurement.

4. The ophthalmic emulsion according to claim 1 , which meets the zeta potential stability as determined by Test D:

measuring zeta potential, in mV, of said emulsion at the time of preparation is Z 0 ,

sealing 5-10 ml of said emulsion in 10 ml Type I glass vials under nitrogen atmosphere without bubbling,

storing said sealed vials at 80° C. for 14 days,

measuring zeta potential, in mV, of said emulsion at 14 days, Z 14 ,

determining the difference between Z 14 −Z 0 , δA, wherein, the emulsion meets the zeta potential stability under thermal stress conditions according to Test D for a δA less than the standard error of zeta potential measurement.

5. The ophthalmic oil-in-water emulsion according to claim 1 , further comprising a biguanide salt selected from the group consisting of chlorhexidine and salts thereof, polyaminopropyl biguanide, phenformin, alkylbiguanide and a mixture of two or more thereof.

6. The ophthalmic emulsion according to claim 1 , further comprising a cationic agent selected from the group consisting of benzalkonium chloride, lauralkonium chloride, benzododecinium bromide, benzethenium chloride, hexacdecyltrimethylammonium bromide, tetradecyltrimethylammonium bromide, dodecyltrimethylammonium bromide and a mixture of two or more thereof.

7. The ophthalmic emulsion according to claim 1 , wherein the cationic agent is selected from the group consisting of chitosan, 1,2-dioleyl-3-trimethylammonium-propane, 1,2-dioleoyl-sn-glycero-phosphatidylethanolamine, cationic glycosphingo-lipids or cationic cholesterol derivatives, and mixtures of two or more thereof.

8. The ophthalmic emulsion according to claim 1 , further comprising benzalkonium chloride as a cationic agent.

9. The ophthalmic emulsion according to claim 1 , wherein said colloidal particles have an average particle size of equal or less than 1 μm.

10. The ophthalmic emulsion according to claim 1 , comprising a pharmaceutically active substance.

11. The ophthalmic emulsion according to claim 10 , wherein the active substance is selected from the group consisting of antibiotics, antifungals, antibacterials, antivirals, anti-infection, anti-microbial drugs, antiallergenic, antiproliferative agents, synthetic glucocorticoids, mineralcerticoid, hormone forms deriving from the cholesterol metabolism, anti-inflammatory, antineoplastic, immunological drugs, insulin, calcitonin, parathyroid hormone and peptide, vaseppressin hypothalamus releasing factor, beta adrenergic blockers, cytokines, interleukins, growth factors, antibodies or antibody fragments, oligoaptamers, aptamers, immunosuppressant, immunomodulators, antithroinbolytic, vasodilator agents, antioxidants, and optically acceptable salts thereof.

12. The ophthalmic emulsion according to claim 10 , wherein the active substance is an immunosuppressive agent selected from the group consisting of cyclosporine, sirolimus and tacrolimus.

13. The ophthalmic emulsion according to claim 12 , wherein the active substance is cyclosporin A.

14. A process of preparation of a submicron ophthalmic oil-in-water type emulsion according to claim 1 , comprising the steps of shear mixing followed by high pressure homogenization of the coarse emulsions obtained through mixing of the aqueous and the oily phase.

15. An ophthalmic formulation comprising a submicron emulsion according to claim 1 , in combination with an ophthalmic acceptable carrier, said formulation being in the form of eye drops, eye ointment, or ophthalmic gel.

16. The ophthalmic formulation according to claim 15 , comprising a pharmaceutically effective amount of an active ingredient in or within the ophthalmic acceptable carrier.

17. A delivery device selected from the group consisting of lenses, ocular patch, implant, and insert, said device containing an emulsion according to claim 1 .

18. The ophthalmic oil-in-water emulsion according to claim 1 , wherein the halide is chloride or bromide.

19. The ophthalmic oil-in-water emulsion according to claim 18 , wherein the halide is chloride.