Crosslinked chondroitin sulfate, composition containing same, and treatment agent for eye disease

1. A method for the treatment of a corneal epithelial disorder and/or dry eye in a subject in need thereof, the method comprising administering a composition comprising a chondroitin sulfate derivative having a cross-linked structure through a cross-linker, the derivative being cross-linked between disaccharide units of chondroitin sulfate, and a pharmaceutically acceptable carrier to at least one eye of the subject,

wherein the composition is in the form of an aqueous solution, and

wherein the composition passes through a porous filter (pore size: 5.0 μm, diameter: 25 mm) at a passing rate of 80% or more at 25° C.

2. The method according to claim 1 , wherein the composition is administered to the eye by instillation.

3. The method according to claim 1 , wherein the composition serves as an aqueous eye drop.

4. The method according to claim 1 , wherein the treatment is therapy.

5. The method according to claim 1 , wherein the cross-linker is a residue derived from at least one species selected from the group consisting of a polyvalent amine, a polyvalent epoxy compound, a polyvalent vinyl compound, and an epihalohydrin.

6. The method according to claim 1 , wherein the cross-linker is a residue derived from a polyvalent amine.

7. The method according to claim 6 , wherein the polyvalent amine is a substituted or unsubstituted polyvalent amine having 1 to 20 atoms in the main chain and optionally having a heteroatom in the main chain.

8. The method according to claim 6 , wherein the polyvalent amine is at least one species selected from the group consisting of ethane 1,2-diamine, 1,3-diaminopropane, 1,4-diaminobutane, 1,5-diaminopentane, 1,6-diaminohexane, 1,8-diaminooctane, 1,12-diaminododecane, spermidine, L-lysine ethylester, L-ornithine ethyl ester, 1,3-diamino-2-propanol, 2-(aminomethyl)-2-methylpropane-1,3-diamine, (E)-2-butene-1,4-diamine, 1,4-bis(aminomethyl)benzene,1,4-bis(aminomethyl)cyclohexane, 2,2′-thiodiethanamine, 2,2′-oxydiethanamine, 1,11-diamino-3,6,9-trioxaundecane, and a salt form thereof.

9. The method according to claim 1 , wherein the cross-linked structure is represented by the following formula (I):

Y—CO—NH—R—NH—CO—Z  (I)

(where Y—CO— represents a disaccharide unit moiety in a chondroitin sulfate molecule; —CO—Z represents a disaccharide unit moiety in the same chondroitin sulfate molecule or a different chondroitin sulfate molecule;

R represents a substituted or unsubstituted hydrocarbon group optionally having a heteroatom in the main chain; and

—CO—NH— and —NH—CO— each represent an amide bond formed between an amino group of a polyvalent amine and a carboxy group of a glucuronic acid, which is a constitutive sugar moiety in chondroitin sulfate).

10. The method according to claim 9 , wherein the hydrocarbon group has 1 to 20 carbon atoms in the main chain.

11. The method according to claim 3 , wherein the aqueous eye drop is administered topically to the eye.

12. The method according to claim 1 , wherein the composition is administered topically to the eye.