JPH10226704A - Accelerator for extension of corneal epithelial layer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a remedy which accelerates the extension of the corneal epithelial layer, can be used to treat actively the cornea when corneal epithelial cells are lost due to herpes corneae, a trauma, an acid, an alkali or the like and can be locally administered by selecting a remedy containing a specified amount of hyaluronic acid of a specified molecular weight or a salt thereof. SOLUTION: The hyaluronic acid or slat thereof is one having a molecular weight of 500,000-3,000,000, desirably 600,000-1,200,000 and is usually a sodium salt, which may be substituted by a potassium salt. The hyaluronic acid having a molecular weight of 600,000-1,200,000 is obtained by digesting crests with protease, precipitating the product from methylpyridinium chloride and fractionating the precipitate with ethanol. This hyaluronic acid is used in the form of an eye drop preparation having a hyaluronic acid concentration of desirably 200-5,000μg/ml. The accelerator may further contain additives such as sodium chloride, a preservative and an inflammatory in addition to the hyaluronic acid. Many experiments have confirmed the safety of the remedy.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to an agent for promoting the spread of a corneal epithelial layer comprising hyaluronic acid or a salt thereof.

[0002]

2. Description of the Related Art The cornea is composed of five layers: an epithelial cell layer, a Bowman's membrane, a stromal layer, a Descemet's membrane, and an endothelial cell layer.

[0003] The epithelial cell layer may be damaged and damaged by corneal herpes, trauma, alkali, acid, etc., but in addition to preventing infection and drying of the cornea and maintaining spontaneous healing, it has been active. There is no specific treatment, and no drug that promotes the cure of such disorders has been known.

Recently, it has been reported that fibronectin prepared from the patient's own plasma has a remarkable effect on epithelial recoating (Nishida, T., et al: Ophthalmol., 92 , 213 (1985);
Watanabe, K., et al: Invest. Ophthalmol. Vis. Sc
i., 28 , 205 (1987)), although it is used in some hospitals, but has poor stability and antigenicity, and thus lacks versatility.

On the other hand, it is known that hyaluronic acid has physical properties such as water retention, lubricating action, high viscoelasticity and various physiological activities. In the ophthalmic field, it is applied to the treatment of keratoderma using the corneal protective action and the corneal surface drying preventive action based on the physical properties (Japanese Patent Application Laid-Open No. 60-84225).

However, there has been no report on the active therapeutic effect of hyaluronic acid on disorders of the corneal epithelial layer.

The present inventors have conducted intensive studies on the effects of hyaluronic acid on the corneal epithelial layer, and as a result,
The present inventors have found that hyaluronic acid has an effect of promoting the extension of the corneal epithelial layer, and have completed the present invention.

[0008]

SUMMARY OF THE INVENTION The present invention relates to an agent for promoting the spread of a corneal epithelial layer, which comprises hyaluronic acid or a salt thereof as an active ingredient.

[0009] The therapeutic agent of the present invention is useful for treating corneal epithelial dysfunction without lacrimation in mammals including humans, ie, superficial punctate keratitis (SPK), corneal epithelial erosion, corneal epithelial defect, corneal ulcer, etc. It is a drug that is administered locally to the disease site as a therapeutic agent that promotes the extension of the corneal epithelial layer of the disorder.

As a salt of hyaluronic acid, a sodium salt is usually used, but a potassium salt or the like may be used.

The hyaluronic acid or a salt thereof used in the present invention preferably has a molecular weight of 500,000 to 3,000,000, more preferably 600,000 to 1,200,000.
When the molecular weight is less than 500,000 or more than 3,000,000, the effect of promoting the extension of the corneal epithelial layer is reduced.

[0012] Hyaluronic acid having a molecular weight of 600,000 to 1,200,000 can be obtained by digesting chicken wort with protease, precipitating methylpyridinium chloride, and fractionating ethanol (Japanese Patent No. 128402).
No. 3, JP-B-61-2241).

The corneal epithelial layer spreading promoter of the present invention can be used in any form known as ophthalmic pharmaceutical preparations, as long as it conforms to the purpose of the present invention. Preferably, hyaluronic acid or a salt thereof is used. , Ie, a liquid preparation for eye drops. The concentration of hyaluronic acid at that time is preferably 200 to 5,000 μg / ml. When the concentration is less than 200 μg / ml or more than 5,000 μg / ml, the effect of promoting the extension of the corneal epithelial layer decreases. In the case of a liquid preparation for eye drops, if it exceeds 5,000 μg / ml, handling and administration (application) become difficult.

[0014] In addition to hyaluronic acid, other additives such as salts such as sodium chloride, disodium hydrogen phosphate and monopotassium hydrogen phosphate, and paraoxybenzoates may be used in the present invention. , A preservative such as benzalkonium chloride, an anti-inflammatory agent such as chondroitin sulfate and glycyrrhizin, and the like may be appropriately added.

When clinically applying the corneal epithelial layer spreading promoter of the present invention as a liquid preparation for eye drops, the phosphate buffered physiological saline has a molecular weight of 500,000 to 3,000,000, preferably 600,000 to 1,200,000. Sodium hyaluronate 200 ~
5,000 μg / ml dissolved at a concentration of 1 to 10 per day
Apply 1 to 3 drops once. The safety (toxicity and non-inflammatory properties) of hyaluronic acid has already been subjected to numerous experiments, and its safety has been confirmed. For example,
For eye toxicity, irritation,
No antigenicity has been confirmed (Norio Ueno et al .: Bulletin of Japanese Ophthalmology 35 , 584 (1984) and 35 , 803 (1984)).

[0016]

The present invention will be described in more detail with reference to the following Examples, which do not limit the scope of the present invention.

Embodiment 1 1. Animals 6 Japanese white native rabbits (male) weighing 2.8-3.0 kg
0 animals were used.

2. Sodium hyaluronate, sodium chondroitin sulfate, sodium heparan sulfate The following glycosaminoglycan (GAG) was used as a sample for the test. Sodium hyaluronate (Na
-HA) has a molecular weight of 4,000, 20,000, 100,000, 500,000, 68
Ten thousand and one hundred and twenty thousand were used. Sodium chondroitin sulfate (Na-Chs) and sodium heparan sulfate (Na-HS) used had a molecular weight of 30,000. Na-
HA is from cockscomb, Na-Chs is from shark cartilage, Na-
HS is purified from bovine kidney and is manufactured by Seikagaku Corporation.

3. Culture of corneal slices Watanabe et al. Method (Watanabe, T., et al: Invest.Oph.
thalmol. Vis. Sci., 28 , 205 (1987)). The sclerocorneal piece was separated from the excised rabbit eyeball, and vertically divided into two parts at the center. One of the two parts is dextran T40.
Was cultivated in a 199 medium containing 5% as a control group. The other was cultured in a medium supplemented with various glycosaminoglycans (GAG). The concentration of GAG was 400 μg / ml.
For Na-HA having a molecular weight of 680,000, a concentration of 5
0, 100, 200, 400, 800, 2,500 μg /
ml was also considered. Nine eyes were used for the GAG group of each concentration and molecular weight, and a control group was provided for each, and the experiment was performed independently. Culture time is 20 hours, temperature is 37 ° C, C
The O ₂ concentration was 5%.

4. Preparation of Pathological Specimens After culturing, the corneal slices were washed with phosphate buffered saline (PB
After washing with S), the cells were fixed with a 100 mM sodium phosphate buffer (pH 7.2) containing 3% glutaraldehyde and 2.5% formaldehyde for 15 hours. After fixing, 2 more
The cells were divided and fixed for another 24 hours or more except for the sclera. Next, the cells were embedded in paraffin, sectioned, hematoxylin-eosin stain (HE stain), and sealed as usual.

5. Measurement of epithelial layer extension distance A photograph of the cut surface of the corneal stromal layer was taken at a magnification of 100 times and 85 × 12
The stretch distance of the epithelial layer was measured from the print stretched to 0 mm. After the measurement, a mean value and a standard deviation were calculated, and a significant difference test was performed. The test involves t- between two paired samples.
The test was used.

[Results] The effects of various concentrations of Na-HA (molecular weight: 680,000) on the extension of the corneal epithelial layer are shown in FIG. The results are expressed as a percentage of the control group. At concentrations of 200, 400, and 800 μg / ml, a significant effect of promoting epithelial layer extension was observed, and at a concentration of 400 μg / ml, the extension distance was longest (p <0.005). Therefore, in the following experiment, the concentration was fixed at 400 μg / ml. Na-HA of various molecular weights (concentration 40) for corneal epithelial layer extension
0 μg / ml) is shown in FIG. Na of any molecular weight
-HA also has the effect of promoting extension, and has a molecular weight of 500,000 and 6
It was significant at 80,000 and 1,200,000. The effect of other GAGs on the extension of the corneal epithelial layer is shown in FIG. Na-Chs and Na-HS with a molecular weight of 30,000 and a concentration of 400 μg / ml slightly promoted extension, but no significant difference was observed.

Embodiment 2 1. Animal White Japanese native rabbit (male) weighing 2.6-3.5 kg 6
Were used.

2. Sodium hyaluronate A solution prepared by dissolving Na-HA having a molecular weight of 720,000 in a physiological saline solution at a concentration of 0.5% was used.

3. Peeling of the corneal epithelial layer In order to peel the epithelial layer of a certain area, 20 g of iodine was put into a test tube with a rim having an inner diameter of 10 mm and a length of about 50 mm, and a tip filled with glass wool was used.
G., et al: Invest. Ophthalmol. Vis. Sci., 18 , 103
(1979)). Rabbits were general anesthetized with pentobarbital,
After local anesthesia by instilling oxybuprocaine hydrochloride, the opening of the test tube filled with iodine was lightly pressed on the central part of the rabbit cornea for 3.5 minutes, and the epithelial layer was damaged by iodine gas. The epithelial layer detached 2-3 hours after the injury. Obstructions due to iodine gas are carried out at 9:00 am, 1:00 pm and 5:00 pm, 9:00 am and 1:00 pm, 5:00 pm the next day.
00 was instilled. 0.5% Na-HA was instilled in the right eye and physiological saline was instilled in the left eye.

4. Staining and photographing of exfoliated site 48 hours after the injury by iodine gas, the exfoliated site of the epithelial layer was stained by instilling a 2% saline solution of fluorescein, and photographed under ultraviolet light of 356 nm. The diameter of the peeled part was measured from the photo print, and the average value and standard deviation were calculated. To test for a significant difference, t-
The test was used.

[Results] The corneas stained with fluorescein were visually observed 48 hours after the injury caused by iodine gas.
It was observed that the detached portion of the epithelium layer of the cornea where Na-HA was applied was reduced. FIG. 4 shows measured values of the diameter of the detached portion of the epithelial layer. The diameter of the Na-HA ophthalmic group was significantly (P <0.05) smaller than that of the physiological saline group.
As described above, in vivo with 0.5% Na-HA instilled
The effect of promoting the recoating of the epithelial layer was also observed in the o system, suggesting that Na-HA may be an effective therapeutic agent for prolonged corneal epithelial layer disorder. is there.

[0028]

According to the present invention, there can be provided an agent for promoting the spread of the corneal epithelial layer and an agent for promoting the healing of the epithelial layer after corneal transplantation.

[Brief description of the drawings]

FIG. 1: Different concentrations of Na-H on corneal epithelial layer extension
It is a figure which shows the effect | action of A.

FIG. 2. Different molecular weights of Na− on corneal epithelial layer extension.
It is a figure which shows the effect | action of HA.

FIG. 3 shows the effect of various GAGs on corneal epithelial layer extension.

FIG. 4 is a diagram showing the diameter of a corneal epithelial layer exfoliation site 48 hours after injury with iodine gas.

Claims (1)

[Claims] 1. A corneal epithelial layer spreading promoter comprising 200 to 5,000 μg / ml of hyaluronic acid or a salt thereof having a molecular weight of 500,000 to 3,000,000.