JP4393863B2 - Optic nerve cell protective agent - Google Patents

Description

  The present invention is represented by the following formula represented by topiramate:

The optic nerve cell protective agent which contains the sulfamate derivative shown by these as an active ingredient, and the method for protection of an optic nerve cell using this sulfamate derivative.

  The retina has a function of receiving light from the outside, and plays an important role in terms of visual function. Structurally, the retina is a tissue having a thickness of about 0.1 to 0.5 mm, which is composed of 10 layers such as the skin on the retinal pigment, the inner plexiform layer, the ganglion cell layer, and the nerve fiber layer. In the inner plexiform layer, there are nerve cells that form a synapse in pairs with ganglion cell processes called amacrine cells. This is considered to work as a light intensity detector since it responds well at the start and end of light irradiation. In the ganglion cell layer, there are nerve cells whose cell bodies are located on the innermost side of the retina, and are deeply involved in motor vision, peripheral vision, color vision, morphological vision, and the like. In addition, retinal blood vessels, which are branches of the central retinal arteriovenous vein, run in the nerve fiber layer and play a role in supplying oxygen and nutrients to the optic nerve.

  Recently, in glaucoma, nerve fiber dropout due to ganglion cell death eventually occurs due to retinal blood flow circulation and optic nerve axon transport failure, and it progresses to visual field impairment. The concept of so-called “neuroprotection” is being established that prevention or minimization treatment leads to ultimate glaucoma treatment (Ophthalmology, 40, 251-273, 1998). In fact, damage to the retinal ganglion cell layer and the optic nerve head was observed in rats with high intraocular pressure ischemia (Grafesrch. Clin. Exp. Ophthalmol., 234, 445-451, 1996) and in rabbits with high intraocular pressure induced by methylcellulose. After 10 days of high intraocular pressure, a significant decrease in retinal ganglion cell density and a significant increase in glial cell density were observed, and there was a correlation between ganglion cell shedding and cell size (GraefesArch. Clin. Exp). Ophthalmol., 234, S209-S213, 1996).

  When the retinal blood vessels are blocked or constricted due to factors such as spasm, thrombus, arteriosclerosis, the retinal blood circulation is impaired, and the supply of oxygen and nutrients to the retina and optic nerve is closed. Retinal blood circulation disorders occupy a particularly important position among retinal diseases. Representative examples of symptoms associated with retinal blood circulation disorders are retinal vascular occlusion in which retinal veins and retinal arteries are blocked or constricted, diabetic retinopathy that contributes to retinal detachment, and ischemic appearance I have optic neuropathy. Furthermore, this retinal blood circulation disturbance causes a shortage of oxygen and nutrient supply, resulting in death of retinal ganglion cells. In other retinal diseases such as macular degeneration, retinitis pigmentosa, and Label disease, this ganglion cell death is considered to be deeply involved in the onset.

  In addition, it has been elucidated that apoptosis, which is a form of programmed cell death, is involved in various pathologies in eye diseases. For example, retinal damage caused by ischemia-reperfusion (J. Ocul. Pharmacol. Ther., 11, 253-259, 1995), retinal detachment (Arc. Ophthalmol., 113, 880-886, 1995), retinitis pigmentosa (Proc. Natl. Acad. Sci. USA, 91, 974-978, 1994, Invest. Ophthalmol. Vis. Sci., 35, 2692-2699, 1994), retinal photopathy (Invest. Ophthalmol. Vis. Sci., 37, 775-782, 1996), glaucoma (Invest. Ophthalmol. Vis. Sci., 36, 774-786, 1995, Exp. Eye Res., 61, 33-44, 1995) and the like. It has been reported that may occur. In other words, even if the cause is diverse, the resulting visual dysfunction is likely to be caused by apoptosis of neurons constituting the visual information network.

  On the other hand, topiramate has the following formula:

2,3: 4,5-bis-O- (1-methylethylidene) -β-D-fructopyranose sulfamate is known as a compound having anticonvulsant activity (for example, Japanese Patent Publication No. 5-5824) ), It has been reported to be effective as a treatment for epilepsy (Nichi Pharmacology, 115, 53-57, 2000, Am. J. Health-Sys Pharm., 55, 554-562, 1998). In addition, topiramate has an inhibitory action on carbonic acid dehydrogenase involved in aqueous humor production, and it has been reported that it is useful as an intraocular pressure lowering agent in the treatment of glaucoma (Japanese Patent Publication No. 5-5824).

  PCT International Publication WO 00/61138 discloses that topiramate and its derivatives are useful for the treatment of chronic neurodegenerative disorders including diabetic neuropathy and diabetic retinopathy.

  Furthermore, PCT International Publication WO 98/00124 discloses that topiramate and its derivatives are useful for the treatment of acute ischemic neuropathy.

  However, topiramate does not involve carbonic acid dehydrogenase, and retinal vascular occlusion, ischemic optic neuropathy, macular degeneration, retinitis pigmentosa, label disease, and other eye diseases such as retinal diseases and glaucomatous neuropathy. There is no report on how it affects, nor is it known how topiramate affects eye tissue, particularly optic nerve cells such as retinal ganglion cells.

  In the course of development research of topiramate as a therapeutic agent for glaucoma, the present inventors have surprisingly found that the sulfamate derivative of the formula (I) represented by topiramate acts directly on optic nerve cells to induce apoptosis of retinal neurons. In addition to being effective in suppressing cell number reduction in the ganglion cell layer and thinning of the inner plexiform layer, it is also effective in suppressing various effects caused by apoptosis of retinal neurons. The present invention has been found to be useful for the prevention or treatment of diseases such as glaucomatous optic neuropathy, retinal vascular occlusion disease, ischemic optic neuropathy, macular degeneration, retinitis pigmentosa, label disease, etc. It came to complete.

  Thus, the present invention provides a formula

An optic nerve cell protective agent comprising a sulfamate derivative represented by the formula: as an active ingredient is provided.

  The present invention also provides a method for protecting optic nerve cells of a patient, characterized by administering the sulfamate derivative of the above formula (I) to the patient.

  The sulfamate derivative of the formula (I) includes optical isomers and diastereoisomers. The sulfamate derivative of the formula (I) used as an active ingredient in the drug of the present invention includes these isomers and their isomers. Also included are mixtures of these. The sulfamate derivative of formula (I) used in the present invention may be in the form of a hydrate, for example. Of the sulfamate derivatives of the formula (I), topiramate represented by the formula (II) is particularly preferred.

  The optic nerve cells protected by the agent of the present invention include retinal ganglion cells, amacrine cells, bipolar cells, horizontal cells, photoreceptor cells, etc. Among them, the agent of the present invention is especially a retinal ganglion cell. Acts effectively against apoptosis.

  The optic nerve cell protective action of the sulfamate derivative of the formula (I) according to the present invention will be specifically described by the following pharmacological test using topiramate.

[Pharmacological test]
In order to examine the protective effect of topiramate on optic nerve cells, the following methods were used to examine topiramate: (1) the effects on glutamate-induced death of cultured rat fetal retinal neurons and (2) the effects on rat hydraulic stress ischemia-induced retinal damage. did.

(1) Action of topiramate on rat fetal cultured retinal neuronal cell death induced by glutamic acid. Retinal cells were extracted and isolated from rat fetus (17-19 days old) and 10% bovine fetus on a polyethyleneimine-coated plastic coverslip. Cultured in serum-containing Eagle basal medium for 7 days. From the 8th day, the cells were cultured in an Eagle basal medium containing 10% horse serum. On day 6 of culture, cytosine arabinoside (10 μM) was added to suppress the growth of non-neuronal cells. Next, the cells were incubated for 10 minutes (37 ° C., 5% CO ₂ .95% air) in a medium containing serum-free Eagle basal medium supplemented with glutamic acid (1 mM) and various concentrations of topiramate (10 nM to 100 μM). Cells were returned to serum-free Eagle's basal medium without glutamate and topiramate, and incubated for 1 hour (37 ° C., 5% CO ₂ .95% air), and then toxicity was determined by trypan blue removal method. That is, the cells were fixed with a 10% neutral formalin solution and washed with a physiological saline solution, and then the cells were stained by adding a trypan blue solution, and the cells were counted under a phase contrast microscope. At that time, the cells stained with trypan blue were regarded as dead cells, and the unstained cells were regarded as viable cells, and the viability of the cultured cells was determined from the ratio of viable cells to the total number of counted cells (200 or more). The group to which 1 mM glutamic acid was added alone and the group to which both 1 mM glutamic acid and each concentration of topiramate were added were designated as “1 mM glutamic acid alone added group” and “1 mM glutamic acid + (various concentration) topiramate added group”, respectively. These results were compared with the corresponding measurements for the “untreated group” that had not been treated at all. The experimental results are shown in Table 1. The values in the table are average values.

(2) Effects of topiramate on rat water pressure ischemia-induced retinal damage Rats were anesthetized with 3% halothane and maintained with 1% halothane (halothane was oxygen 0.5 L / min, gustation 1.5 L / min Vaporize). Next, the right eye is dilated with an atropine ophthalmic solution, and a 30G injection needle connected through a tube in which a physiological saline infusion container is suspended from the ceiling is inserted into the anterior chamber, so that a water pressure of 130 mmHg is applied. Loaded and induced ischemia. After 45 minutes, the needle was removed and retinal blood flow was reperfused. Administration was carried out by injecting physiological saline (solvent) and topiramate (200 mg / kg body weight) dissolved in a solvent (partially suspended) into the abdominal cavity of each rat. Administration was performed twice, 2 hours before ischemic load and immediately after ischemic load. Seven days after administration, the eyeball was removed, fixed in 2% paraformaldehyde-2.5% glutaraldehyde overnight, embedded in paraffin, sliced, and stained with hematoxylin-eosin (HE) (3 μm). Thickness). Arbitrary 3 slices were selected from 8 slices prepared at intervals of 60 μm so that the optic disc was inserted into each eye, and a photograph of the retina between 1 and 1.5 mm from the optic disc to the left or right was selected for the selected slice. The number of cells in the ganglion cell layer (GCL) and the thickness of the inner plexiform layer (IPL) in the retina were measured. The groups that were subjected to ischemia by administering the solvent and the groups that were subjected to ischemia by administering the topiramate dissolved in the solvent were referred to as “solvent administration group” and “topiramate administration group”, respectively. These results were compared with the corresponding measurements for the “normal (untreated) group” that had not been treated at all. The experimental results are shown in Table 2. The values in the table are average values.

  According to the results shown in Table 1 above, it can be seen that topiramate has an effect of significantly suppressing cultured retinal neuronal cell death (apoptosis) in a concentration-dependent manner. Further, as is apparent from the results shown in Table 2 above, it can be seen that topiramate is excellent in suppressing the decrease in the number of cells in the ganglion cells and the thinning of the inner plexiform layer.

  Therefore, the sulfamate derivative of the above formula (I) represented by topiramate is a protective agent for optic nerve cells such as retinal ganglion cells, such as retinal vascular occlusion, diabetic retinopathy, ischemic optic neuropathy, macular degeneration, It is extremely useful as a preventive or therapeutic agent for eye diseases such as retinal diseases such as retinitis pigmentosa and labeling disease and glaucomatous optic neuropathy.

  The sulfamate derivatives of formula (I) can be administered orally or parenterally to patients (mammals, in particular humans) when used for the prevention or treatment of these eye diseases. A pharmaceutical dosage form suitable for administration is formulated with a pharmaceutically acceptable additive. Examples of dosage forms suitable for oral administration include tablets, capsules, granules, powders and the like, and dosage forms suitable for parenteral administration include injections, eye drops, and nasal drops. And suppositories, and the like, and these can be formulated using ordinary techniques widely used in the art.

  For example, the tablet is an excipient such as lactose, glucose, D-mannitol, anhydrous calcium hydrogen phosphate, starch, sucrose; carboxymethylcellulose, carboxymethylcellulose calcium, croscarmellose sodium, crospovidone, starch, partially pregelatinized starch , Disintegrating agents such as low-substituted hydroxypropylcellulose; binders such as hydroxypropylcellulose, ethylcellulose, gum arabic, starch, partially pregelatinized starch, polyvinylpyrrolidone, polyvinyl alcohol; magnesium stearate, calcium stearate, talc, hydrous silicon dioxide , Lubricants such as hydrogenated oils; refined sucrose, hydroxypropylmethylcellulose, hydroxypropylcellulose, methylcellulose, ethylcellulose, polyvinyl chloride Coating agents such as pyrrolidone; citric acid, aspartame, ascorbic acid, may be formulated using appropriately selected and flavoring agents such as menthol.

  The injection can be prepared using sterile purified water and sodium chloride for isotonicity.

  Further, the eye drops include isotonic agents such as sodium chloride and concentrated glycerin; buffering agents such as sodium phosphate and sodium acetate; polyoxyethylene sorbitan monooleate, polyoxyl 40 stearate, polyoxyethylene hydrogenated castor oil, etc. Surfactant; Stabilizers such as sodium citrate and sodium edetate; Preservatives such as benzalkonium chloride and paraben can be selected and used as needed, and the pH can be adjusted to ophthalmic preparations. Although it may be within the allowable range, it is usually preferably within the range of 4-8.

  The dosage of the sulfamate derivative of formula (I), for example topiramate, can be appropriately changed according to the dosage form, the severity of the patient's symptoms to be administered, age, weight, doctor's judgment, etc. In general, 0.1 to 2000 mg per day can be administered to adults in one or several divided doses, and in the case of injections, generally 0.01 to 200 mg can be administered once or in several divided doses. Furthermore, in the case of eye drops, an active ingredient concentration of 0.1 to 10% (w / v) can usually be instilled once or several times a day.

  Next, the pharmaceutical agent of the present invention will be described more specifically with reference to formulation examples, but the present invention is not limited to these formulation examples.

Formulation example

Formulation Example 1 (tablet)
Formula: Topiramate 1 mg
Lactose 66.4 mg
Corn starch 20 mg
Carboxymethylcellulose calcium 6 mg
Hydroxypropylcellulose 6 mg
Magnesium stearate 0.6 mg
Total 100 mg
Topiramate, lactose and corn starch are mixed in a blender, carboxymethylcellulose calcium and hydroxypropylcellulose are added to the mixture and granulated. The resulting granules are dried and sized, and the sized granules are magnesium stearate. Add and mix and tablet with a tableting machine.

Formulation Example 2 (Injection)
Formula: Topiramate 10mg
Sodium chloride 90mg
Sterile purified water The amount required to make the whole 10 ml Topiramate and sodium chloride are dissolved in sterile purified water to make an injection solution.

Formulation Example 3 (eye drops)
Formula: Topiramate 1mg
Concentrated glycerin 250mg
Polysorbate 80 200mg
Sodium dihydrogen phosphate dihydrate 20mg
IN sodium hydroxide appropriate amount IN hydrochloric acid appropriate amount sterilized purified water appropriate amount
10ml total
Add topiramate and other ingredients to sterilized purified water and mix well to make eye drops.

Claims (12)

formula

Characterized in that it contains the sulfamate derivative as an active ingredient with, retinal vascular occlusion, ischemic optic neuropathy, macular degeneration, selected from the group consisting of retinitis pigmentosa and Leber's disease, involving carbonic anhydrase Drugs to protect retinal neurons from apoptosis in eye diseases that do not. Drugs agent according to claim 1 sulfamate derivative of formula (I) is topiramate. Drugs agent according to claim 1 retinal neuronal cell is a retinal ganglion cell. Drugs agent according to claim 1 for use for the prevention or treatment of eye diseases. Drugs agent according to claim 1 effective ingredient is an oral dosage form is administered in an amount of 0.1 to 2000 mg / day. Drugs agent according to claim 1 effective ingredient is in the form of an injection to be administered in an amount of 0.01 to 200 mg / day.   The drug according to claim 1, which is in the form of eye drops having an active ingredient concentration of 0.1 to 10% (w / v). Formula for the manufacture of a medicament for treating an eye disease not involving carbonic acid dehydrogenase, selected from the group consisting of retinal vascular occlusion, ischemic optic neuropathy, macular degeneration, retinitis pigmentosa and label disease

Use of a sulfamate derivative having Use according to claim 8 , wherein the sulfamate derivative of formula (I) is topiramate. Use according to claim 8 , wherein the sulfamate derivative of formula (I) is orally administered in an amount of 0.1 to 2000 mg / day. Use according to claim 8 , wherein the sulfamate derivative of formula (I) is injected in an amount of 0.01 to 200 mg / day. Use according to claim 8 , wherein the sulfamate derivative of formula (I) is administered in the form of eye drops having an active ingredient concentration of 0.01 to 10% (w / v).