JPS634527B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a method for producing an artificial aqueous humour, which is used as an intraocular irrigating solution, or as a cleaning solution or preservation solution for the eyeball, ocular tissue, such as the cornea. In recent years, with the progress and spread of ophthalmic surgeries such as cataract, iris, vitreous, and corneal transplants, there has been a demand for artificial aqueous humor for perfusing the eye during surgery, for example. It must not cause any damage to intraocular tissues. If the intraocular tissue is damaged, the postoperative course will worsen, and there is a risk of complications such as corneal clouding, glaucoma, and retinitis. It is desirable for artificial aqueous humor to have a composition as close as possible to natural aqueous humor, but currently the main ones used for intraocular irrigation are physiological saline and lactated Ringer's solution, and BSS (Balanced salt solution) has also been developed. It is still in progress. Although these are considered stable as formulations, they lack the glucose needed by cells and the bicarbonate ions needed for intraocular irrigation fluids. Merriam and Kinsey previously published a tissue culture medium with an ionic composition similar to that of aqueous humor with the addition of glucose and lactic acid, but this produces a white precipitate when sterilized by heat or left at room temperature for several days. Therefore, it is not preferred as an artificial aqueous humor. Therefore, the present inventors tried removing sodium phosphate, which is thought to be the cause of precipitation, from this formulation, but the formation of precipitation could not be prevented. After examining this precipitate, they discovered that it was a mixture of basic calcium carbonate and basic magnesium carbonate. In order to prevent this precipitation, we tested adding anions that are harmless to living organisms, and found that lactic acid, acetic acid, glutamic acid, gluconate ions, etc. had no effect, but surprisingly, the addition of citrate ions solved the problem. It has been discovered that the formation of precipitates can be completely prevented. The present invention is based on these findings, and is a method for producing stable artificial aqueous humor, which is characterized by adding hydrogen carbonate and citrate ions in the production of artificial aqueous humor containing calcium and magnesium ions. Bicarbonate ions are usually added to the composition of artificial aqueous humor in the form of harmless water-soluble salts, such as sodium salts, potassium salts. The citric acid ion can be citric acid or a harmless water-soluble salt thereof, such as a sodium salt, a potassium salt or an ammonium salt, preferably a sodium salt;
It can be added to the artificial aqueous humor composition in the form of potassium salts. When free citric acid is added as a citrate ion source, the pH of the artificial aqueous humor composition aqueous solution decreases, so the final pH is adjusted to 6.5, which is suitable for artificial aqueous humor.
It is best to adjust it to 7.5, preferably 7-7.5. As the pH adjuster, hydroxides and carbonates of sodium, potassium, lithium, and ammonium are generally used, and preferred are hydroxides and carbonates of sodium and potassium. It is best to add citrate ions in an amount equal to or more than the sum of the concentrations of calcium and magnesium ions in the artificial aqueous humor. Also, precipitation caused by magnesium etc. does not occur. In practice, citrate ion is present in the aqueous humor as citric acid or citrate at 0.07-0.2 (W/
V)% is sufficient. The artificial aqueous humor of the present invention thus obtained does not precipitate even during heat sterilization or long-term storage, and
It is extremely stable with no pH fluctuations. The artificial aqueous humor of the present invention can be used not only as an intraocular irrigation fluid, but also for cleaning and preserving eyeballs and ocular tissues. The present invention will be explained in more detail with reference to Examples below. Example 1 Sodium chloride 6.60g Potassium chloride 0.36g Calcium chloride (dihydrate) 0.18g Magnesium sulfate (7hydrate) 0.30g Sodium hydrogen carbonate 2.10g Sodium citrate (dihydrate) 1.00g Sodium acetate (trihydrate) ) Dissolve 0.60g of glucose or more than 1.50g in approximately 900ml of sterile purified water, add 10g of glucose to this
After adjusting the pH to 7.2 by adding (W/V)% hydrochloric acid,
Add sterile purified water to a total volume of 1000ml and filter aseptically. Add this to 20ml ampoule and 500ml
Fill it into a vial, seal it or seal it, and heat sterilize it. Osmotic pressure is 280-300mOsm. <Time change test> Time change was examined at 40° for 6 months and at room temperature for 24 months, but no change in appearance or PH was observed. <Pharmacological test> 1 According to Otori's method, one cornea of the left eye was placed in 400 ml each of the artificial aqueous humor, physiological saline, lactated Ringer's solution, and BSS and cultured at 37°C. As observation items, changes in water content and sodium, potassium, and chlorine ions in the cultured cornea were measured using the normal cornea of the right eye as a control. As a result, there was almost no difference between the intraocular irrigation solution of the present invention and normal cornea even after 8 and 16 hours of culture. In contrast, although there are individual differences between physiological saline, lactated Ringen's solution, and BSS, differences were observed in 8-hour culture compared to normal values.
At 16 hours, the difference was even more pronounced (Table 1). Note that since physiological saline does not contain potassium ions, potassium ions in the cornea decreased after 8 hours of culture. 2. According to the method of Dikstein and Maurice, the isolated cornea was attached to a corneal fixation device, and the above intraocular irrigating solution, physiological saline, Central corneal thickness was measured under a microscope while perfused with lactated Ringer's solution or BSS for up to 3 hours. Furthermore, after the measurement, Prince
The cells were stained with trypan blue and Alizarin Ret S according to the method of John and Peyman, and observed under a microscope. As a result, when perfusion was performed with the artificial aqueous humor of the present invention, the thickness of the cornea decreased by 15 to 20 μm in 3 hours.
In contrast, it increased by about 350μ with physiological saline, about 150μ with lactated Ringer's solution, and about 90μ with BSS. In addition, observation of corneal endothelial cells after perfusion showed that in the case of the artificial aqueous humor of the present invention, the cell shape was maintained in a normal hexagonal shape, whereas in other solutions, although there were differences in degree, The corners were rounded and there were areas where cells had fallen off, which was especially noticeable in the case of physiological saline. To summarize the above pharmacological tests, the artificial aqueous humor of the present invention is very superior to other drugs and is satisfactory as an artificial aqueous humor.

[Table] Example 2 Sodium chloride 6.60g Potassium chloride 0.36g Calcium chloride (dihydrate) 0.18g Magnesium sulfate (7hydrate) 0.30g Sodium hydrogen carbonate 2.10g Citric acid 0.80g Sodium acetate (trihydrate) 0.60g Dissolve 1.5g or more of glucose in approximately 900ml of sterile purified water, add 1.
Add the specified sodium hydroxide solution to adjust the pH to 7.2, and then add sterile purified water to make a total volume of 1000 ml. After sterile filtration under pressure, this is filled into 20 ml ampoules and 500 ml vials, which are then melted or sealed and sterilized by heating. Regarding stability, changes over time were investigated at 40°C for 6 months and at room temperature for 24 months, but no changes in appearance or pH were observed. Example 3 Sodium chloride 7.00g Calcium chloride (dihydrate) 0.18g Magnesium sulfate (7hydrate) 0.30g Sodium hydrogen carbonate 2.10g Citric acid 1.00g Sodium acetate (trihydrate) 0.60g Glucose 1.50g Sterilize and purify the above Dissolve in approximately 900 ml of water, add potassium carbonate to adjust the pH to 7.2, add sterilized purified water to a total volume of 1000 ml, and filter aseptically under pressure. This is filled into 20 ml ampoules and 500 ml vials, sealed or sealed, and then heat sterilized. As for stability, changes over time were investigated at 40° for 6 months and at room temperature for 24 months, but no changes in appearance or pH were observed. Moreover, both Experimental Examples 2 and 3 showed almost the same medicinal efficacy and pharmacology as Experimental Example 1.

Claims (1)

[Scope of Claims] 1. A method for producing stable artificial aqueous humor, which comprises adding hydrogen carbonate and citrate ions in the production of artificial aqueous humor containing calcium and magnesium ions. 2. The manufacturing method according to claim 1, wherein the artificial aqueous humor contains glucose. 3 PH of artificial aqueous humor is 6.5-7.5, preferably 7-7.5
The manufacturing method according to claim 1 or 2.