REMEDY FOR CORNEAL DAMAGES

Abstract: A remedy for corneal damages caused by the injury to the cornea due to various factors, such as corneal ulcer, corneal erosion, keratitis or xerophthalmia, containing interleukin-6 as the active ingredient.

Description: [Technical Field] The present invention relates to a therapeutic agent for corneal disorders comprising interleukin-6 as an active ingredient. [Background Art] Interleukin-6 has been known as an important physiologically active agent for the immune system, the hematopoietic system, etc. However, research on the medical applications of interleukin-6 have been limited to its use in anti-cancer agents and in medicines for myeloid leukemia (WO Disclosure 88/00206, WO Disclosure 90/01943), and any ophthalmological effect thereof have not been known. The inventor of the present invention conducted thorough research on the pharmacological effects of interleukin-6, particularly in the area of ophthalmology, and found that interleukin-6 is useful for treatment of corneal disorders. [Disclosure of the Invention] The present invention relates to the use of interleukin-6 in the manufacture of a therapeutic preparation for the treatment of corneal disorders. Examples of corneal disorders caused by various cornea damages are corneal ulcer, corneal epithelial defect, keratitis and xerophthalmia. Research is being conducted on various therapeutic drugs therefor. The inventor of the present invention concentrated on the physiologically active substance interleukin-6 and its therapeutic effects on corneal disorders. In order to investigate the therapeutic effects of interleukin-6 on corneal disorders, we studied its effect on corneal epithelial extension in vitro and its accelerating effect on the healing of corneal wounds in vivo. Detailed data is given in the section on the pharmacological experiments. There was a clear extension of the corneal epithelial cell layer in the group to which interleukin-6 was added and a quicker healing of corneal wounds compared with the control group. These were evidence of the effectiveness of interleukin-6 as a therapeutic agent for corneal disorders. The therapeutic agent for corneal disorders is to be preferably administered locally, particularly in the form of eyedrops. The concentration of interleukin-6 in the eyedrop preparation may be determined depending on the symptoms, the age, etc. of the patient; however, it is preferably 0.00001 - 1% w/v. The dosage may be, in the case of eyedrops, from 1 to several drops per use, from 1 to several times per day. The eyedrops may be a normally used in an eyedrop solution, or dissolved before using, or as an eye ointment. No special techniques are necessary for the preparation thereof, and the preparation may be made according to a conventional method, as necessary adding, for example, isotonizing agents such as sodium chloride and potassium chloride; buffers such as disodium hydrogen phosphate and sodium dihydrogen phosphate; stabilizers such as sodium edetate; preservatives such as ethylparaben, butylparaben and benzalkonium chloride; pH adjusting agents such as sodium hydroxide and diluted hydrochloric acid; and eye ointment bases such as white petrolatum and liquid paraffin. Preferred Preparations: 1) Eyedrop Formulation 1 (per 100 ml) Interleukin-6 0.01 g Sodium chloride 0.9 g Sterilized purified water q.s. Eyedrops can also be prepared in the same manner as Formulation 1, but containing 0.00001 g, 0.00003 g, 0.0001 g, 0.0005 g, 0.001 g, 0.005 g, 0.05 g and 0.1 g, respectively, of interleukin-6 per 100 ml. Formulation 2 (per 100 ml) Interleukin-6 0.1 g Sodium chloride 0.8 g Disodium hydrogen phosphate 0.1 g Sodium dihydrogen phosphate q.s. Sterilized purified water q.s. Eyedrops can also be prepared in the same manner as Formulation 2, but containing 0.00001 g, 0.00003 g, 0.0001 g, 0.0005 g, 0.001 g, 0.005 g, 0.01 g, 0.05 g, 0.5 g and 1.0 g, respectively, of interleukin-6 per 100 ml. 2) Eye ointment Formulation 3 (per 100 g) Interleukin-6 0.05 g White petrolatum 90 g Liquid paraffin q.s. Eye ointments can also be prepared in the same manner as Formulation 3, but containing 0.00001 g, 0.00003 g, 0.0001 g, 0.0005 g, 0.001 g, 0.005 g, 0.01 g, 0.1 g, 0.5 g and 1.0 g, respectively, of interleukin-6 per 100 g. [Pharmacological Experiment] In order to determine whether interleukin-6 is useful for the treatment of corneal disorders, we studied its effect on corneal epithelial extension in vitro and its accelerating effect on the healing of corneal wounds in vivo. 1) Effect on corneal epithelial extension in vitro (Method) The corneas of Japanese male white rabbits weighing 2.0 - 3.0 kg were used according to the method of Nishida et al. (The Journal of Cell Biology, 97 , 1653, 1983). Corneal blocks (6-8 per group) cut out from a section of rabbit cornea were cultured for 24 hours in a culture solution containing interleukin-6 (TC-199), and the extension of the corneal epithelial cells was measured. The control group consisted of cells cultured in the same manner in a culture solution which contained none of the drug. (Result) The results are shown in Table 1. Amount of Interleukin-6 added Rate of cell extension with the control group defined as 1 1 ng/ml 1.20 3 ng/ml 1.22 10 ng/ml 1.29 As shown in Table 1, the corneal epithelial cells cultured in the culture solution containing interleukin-6 were clearly observed to be extended in comparison with those in the control group, and the effect was dose-dependent on interleukin-6. 2) Accelerating effect on the healing of corneal wounds in vivo (Method) Japanese male white rabbits weighing 2.0-3.0 kg (one group of 7 = 14 eyes) were used. Corneal epithelial defect was induced with n-heptanol, immediately after which dyeing with fluorescein was performed and a photograph of the cornea was taken. Eyedrops prepared by dissolving interleukin-6 in a vehicle [PBS(-)] as well as a preparation consisting of only the vehicle used for the control was instilled 4 times a day (50 µl/application) of 2 hours interval for 2 days. Twenty-four hours after defect, fluorescein dyeing was conducted and a photograph of the cornea was taken. The area of the corneal wound was calculated by measuring the area of the fluorescein dyeing on the cornea seen in the photograph and using an image analysis processing system (Trade name: Cosmozone 1S, manufactured by Nikon, Inc.). (Result) The areas of the wounds (%) after 24 hours, with the area immediately after corneal epithelial defect defined as 100, are shown in Table 2. Drug Area of wound (%) Control 51.0 Interleukin-6 0.1 µg/ml 39.7 0.3 µg/ml 33.5 1.0 µg/ml 30.5 In every case, the group to which interleukin-6 had been applied showed a decrease in the areas of the wounds in comparison to the control group, and the effect was dose-dependent on interleukin-6. From the above results, it has become clear that interleukin-6 possesses an accelerating effect on the healing of wounds.

Claims: The use of interleukin-6 in the manufacture of a therapeutic preparation for the treatment of corneal disorders. The use as claimed in claim 1, wherein the therapeutic preparation includes one or more pharmaceutically-acceptable excipients. The use as claimed in claim 2, wherein the therapeutic preparation is in the form of eyedrops. The use as claimed in claim 3, wherein the concentration of interleukin-6 in the eyedrop preparation is in the range of 0.00001 - 1% w/v.

Inventors: NISHIDA TERUO, NISHIDA, TERUO, NISHIDA, Teruo 1-34-304, Kaminonaka-Cho
Applicants: NISHIDA TERUO, SANTEN PHARMA CO LTD, NISHIDA, TERUO, SANTEN PHARMACEUTICAL CO., LTD.
Application year: 1991
Main classification: A61K38
IPC codes: A61K38