JP6709501B2 - Glass for drug container and glass tube for drug container - Google Patents

Description

TECHNICAL FIELD The present invention relates to a glass for a pharmaceutical container, which has excellent chemical strengthening properties and chemical durability.

Conventionally, various glass containers have been used as filling containers for storing pharmaceuticals. Pharmaceuticals are roughly divided into two types, oral and parenteral. Especially, for parenterals, the drug filled and stored in a glass container is directly administered into the blood of the patient, so it is extremely difficult to use it Requires high quality.

In addition, it is required that the components of the filled drug in the drug container do not deteriorate. In the glass container, elution of the glass component into the drug changes the properties of the drug, and there is a risk of affecting the health and even life of the patient. Therefore, the elution amount of the glass component of the glass for pharmaceutical containers is limited by the pharmacopoeia of each country.

Borosilicate glass is generally used as a glass material that satisfies the criteria of elution components from glass. Components of the pharmaceutical container borosilicate glass in current use containing _{SiO 2, Al 2 O 3,} B 2 O 3, Na 2 O, K 2 O, CaO, BaO and a small amount of fining agents.

As medicines have become more powerful due to the development of medicine and pharmacy, more and more medicines are eroding glass containers. The phenomenon called delamination in which the inner surface of the glass container is eroded and the inner surface of the container is peeled off and floats in the drug as flakes by filling and storing such a drug in a glass container has become a serious problem. As a solution to this problem, glass as disclosed in Patent Document 1 has been developed.

WO2013/063275

Due to rapid advances in medicine, many kinds of new drugs have been created, and the drugs filled in drug containers are also changing. In the past, drugs such as blood coagulants and anesthetics were relatively inexpensive, but recently, prophylactic drugs such as influenza vaccine, or very expensive drugs such as anticancer drugs are sometimes filled. Is increasing.

The damage of the container filled with such an expensive drug in the manufacturing process of the pharmaceutical company and in the medical field causes a great loss. In particular, when the glass breaks in the manufacturing process, the loss of the high-priced drug itself is large, and the manufacturing loss due to the stop of the manufacturing line is also a problem.

Further, the glass breakage increases the safety risk. There are also injection devices called self-injectors in which the patient himself/herself administers injections, including workers and medical personnel involved in manufacturing, and the risk of glass breakage has become more serious than before.

Generally, the theoretical strength of glass is very high, but if scratches occur, the strength will decrease significantly. Therefore, it is known that the actual strength of glass is weaker than the theoretical strength, and the decrease in strength depends on the depth of the scratch. The scratches present on drug containers such as ampoules, vials, prefilled syringes, and cartridges occur in various processes such as transportation, container processing, inspection, and drug filling, which cause the strength of the final product to decrease.

Chemical strengthening is effective as a method for maintaining the strength of the pharmaceutical container as described above. Chemical strengthening is a method of exchanging alkali ions having a small ionic radius with alkali ions having a large ionic radius to form a compressive stress layer on the glass surface and improve the strength of the glass. A specific method of chemical strengthening is performed by immersing a container shaped into a predetermined shape in KNO ₃ molten salt at 300 to 500° C. for a certain period of time.

The conventional container made of borosilicate glass has a problem that the depth and compressive stress of the compressive stress layer formed on the surface when chemically strengthened are small.

The glass described in Patent Document 1 has a chemical strengthening property superior to that of the conventional borosilicate glass, but has a high viscosity and is disadvantageous in workability.

The technical problem of the present invention is that delamination is unlikely to occur, and that after forming the final product such as an ampoule, a vial, a prefilled syringe, and a cartridge, it is possible to impart a compressive stress layer of sufficient depth to the container by chemical strengthening. It is an object of the present invention to provide a glass for pharmaceutical containers which can be manufactured and is excellent in processability, and a glass tube using the glass.

As a result of various studies, the present inventors have found that the above problem can be solved by optimizing the content of the alkali metal component, and propose as the present invention.

That is, the glass for pharmaceutical containers of the present invention is, in mol %, SiO ₂ 69 to 81%, Al ₂ O ₃ 4 to 12%, B ₂ O ₃ 0 to 5%, Li ₂ O+Na ₂ O+K ₂ O 5 to 20. %, Li ₂ O 0.1 to 5%, Na ₂ O 1 to 11%, K ₂ O 1 to 11%, MgO+CaO+SrO+BaO 0 to 10%, and a molar ratio K ₂ O/Na ₂ O≧0. 3, “MgO+CaO+SrO+BaO”, which is characterized by satisfying a molar ratio of Li ₂ O/(Li ₂ O+Na ₂ O+K ₂ O)≦0.25, means the total content of MgO, CaO, SrO and BaO. .. “K ₂ O/Na ₂ O≧0.3” means that the value obtained by dividing the content of K ₂ O by the content of Na ₂ O is 0.3 or more. The _{"Li 2 O / (Li 2 O} + Na 2 O + K 2 O) ≦ 0.25 ", divided by the total content of the content of _{Li 2 O Li 2 O, Na} 2 O, and _{K 2} O It means that the value is 0.25 or less.

In the glass for a pharmaceutical container of the present invention having the above-mentioned structure, delamination is unlikely to occur because B ₂ O ₃ is small. The K _{2 O} ratio of content and the K _{2 O} content for Na 2 _O of, by further restricting as percentage of the amount of the alkali metal compound (R 2 _O) components, well after the container processing A compressive stress layer of any depth can be applied by chemical strengthening. Therefore, by chemically strengthening the obtained drug container, it is possible to significantly improve the mechanical strength of the container and prevent damage to the container during the drug filling process or in the medical field, or when the patient himself administers the drug. It can be largely prevented. Moreover, since it contains Li ₂ O as an essential component, it has excellent workability and can be easily processed into a complicated shape.

In the present _invention, in _{mol%, SiO 2 69~81%,} Al 2 O 3 4~12%, B 2 O 3 0.01~5%, Li 2 O + Na 2 O + K 2 O 5~20%, Li 2 O 0.1 to 5%, Na ₂ O 1 to 11%, K ₂ O 1 to 11%, MgO+CaO+SrO+BaO 0 to 10%, and a molar ratio K ₂ O/Na ₂ O≧0.34, molar ratio It is preferable to satisfy Li ₂ O/(Li ₂ O+Na ₂ O+K ₂ O)≦0.25.

According to the above configuration, workability is further improved, and it becomes easy to obtain a pharmaceutical container having a deeper compression stress layer.

In the present invention, it is preferable to contain B ₂ O ₃ in an amount of 0.01 to 4 mol %.

According to the above configuration, it is possible to obtain good workability while suppressing the occurrence of delamination.

In the present invention, it is preferable to contain MgO 0 to 9%, CaO 0 to 4%, SrO 0 to 4%, BaO 0 to 4%, and ZrO ₂ 0 to 2% in mol %.

In the present invention, it is preferable that the alkali resistance in a test according to ISO695 is at least class 2. Here, the "test according to ISO 695" refers to the following test.
(1) Prepare a glass sample piece of Acm ² (where A is 10 to 15 cm ² ) with all surfaces mirror-finished, and first of all, as a pretreatment, the sample is hydrofluoric acid aqueous solution (40 wt%) and hydrochloric acid aqueous solution. (2 mol/L) is soaked in a mixed solution having a volume ratio of 1:9, stirred with a magnetic stirrer for 10 minutes, and then a sample is taken out. Subsequently, ultrasonic cleaning with ultrapure water for 2 minutes is performed three times, and then ultrasonic cleaning with ethanol for 1 minute is performed twice.
(2) After that, the sample is dried in an oven at 110° C. for 1 hour and allowed to cool in a desiccator for 30 minutes.
(3) The mass m1 of the sample is measured to an accuracy of ±0.1 mg and recorded.
(4) Put 800 mL of a solution prepared by mixing a sodium hydroxide aqueous solution (1 mol/L) and a sodium carbonate aqueous solution (0.5 mol/L) at a volume ratio of 1:1 into a stainless steel container and using a mantle heater. Heat to boiling and bring to a boil. A sample hung with a platinum wire is put therein and kept for 3 hours.
(5) The sample is taken out, ultrasonically cleaned with ultrapure water for 2 minutes 3 times, and then ultrasonically cleaned with ethanol for 1 minute 2 times. Then, the sample is dried in an oven at 110° C. for 1 hour and left to cool in a desiccator for 30 minutes.
(6) The mass m2 of the sample is measured to an accuracy of ±0.1 mg and recorded.
(7) From the masses m1 and m2 (mg) of the sample before and after being added to the boiling alkaline solution and the total surface area A (cm ² ) of the sample, the mass reduction amount per unit area is calculated by the following calculation formula to obtain the alkali resistance. Use as the measured value of the test.
(Amount of mass reduction per unit area)=100×(m1-m2)/A

The phrase "alkali resistance is class 2 by a test according to ISO 695" means that the measured value obtained above is 175 mg/dm ² or less. If the measured value obtained as described above is 75 mg/dm ² or less, “alkali resistance in a test according to ISO695 is class 1”.

In the present invention, the working point is preferably 1260°C or lower. Here, the “working point” means a temperature at which the viscosity of glass becomes 10 ^4.0 dPa·s.

In the present invention, the compressive stress value of the compressive stress layer formed when the ion exchange treatment is performed for 7 hours in the KNO ₃ molten salt at 475° C. is 300 MPa or more, and the depth of the compressive stress layer is 40 μm or more. Preferably. Here, the “compressive stress value of the compressive stress layer” and the “depth of the compressive stress layer” are observed when the sample is observed using a surface stress meter (for example, FSM-6000 manufactured by Toshiba Corporation). The value calculated from the number of interference fringes and the interval.

The glass tube for a pharmaceutical container of the present invention is preferably made of the above glass for a pharmaceutical container.

In the glass tube for a pharmaceutical container of the present invention, the compressive stress value of the compressive stress layer is preferably 300 MPa or more and the depth of the compressive stress layer is preferably 40 μm or more.

The reason for limiting the composition range of each component will be described. In the following description, "%" means "mol%" unless otherwise specified.

SiO ₂ is one of the constituents of the glass network structure. When the content of SiO ₂ is too small, it becomes difficult to vitrify, the thermal expansion coefficient increases, and the thermal shock resistance tends to decrease. Therefore, the content is 69 to 81%, preferably 69 to 80%, more preferably 70 to 79%, particularly preferably 70 to 78%, and most preferably 74 to 77%.

Al ₂ O ₃ is one of the components that constitutes the network structure of glass, and has the effect of improving the hydrolysis resistance of glass. Its content is 4-12%, preferably 4.5-11%, more preferably 5-10%, most preferably 5.5-7%. If the content of Al ₂ O ₃ is too small, the hydrolysis resistance in a test according to ISO720 described later tends to deteriorate. On the other hand, if the content of Al ₂ O ₃ is too large, it becomes difficult to realize a working point of 1260° C. or lower.

B ₂ O ₃ has the effect of lowering the viscosity of glass and improving the meltability and workability. However, B ₂ O ₃ is considered to be one of the factors that cause delamination, and if the content thereof is too large, the delamination resistance deteriorates and flakes easily occur. That is, the elution amount of SiO ₂ by the delamination resistance test according to the method described in Patent Document 1 is likely to be more than that of the conventional borosilicate glass. Further, if the content of B ₂ O ₃ is too large, the chemical durability is likely to decrease. The content of B ₂ O ₃ is 0 to 5%, preferably 0.01 to 5%, 0.01 to 4%, 0.02 to 3%, 0.03 to 2%, 0.04 to 1 %, particularly preferably 0.05 to 0.5%.

Alkali metal oxides _{(R 2 O) Li 2 O} , Na 2 O and _{K 2} O has an effect of lowering the viscosity of the glass. However, if the total amount of these components increases, the amount of alkali elution from the glass increases, the thermal expansion coefficient increases, and the thermal shock resistance decreases. The total amount of R ₂ O is 5 to 20%, preferably 7 to 17%, 10 to 15%, 10 to 14.5%, and more preferably 10.5-14.5%.

Among R ₂ O, Li ₂ O has the highest effect of lowering the viscosity of glass, followed by Na ₂ O and K ₂ O in that order. Further, when chemical strengthening is performed for a certain period of time, the greater the content of Na ₂ O, the greater the depth of the compressive stress layer formed on the glass surface.

In R ₂ O, when K ₂ O is contained in a certain amount or more with respect to the content of Na ₂ O, the depth of the compressive stress layer becomes larger than that in the case of only Na ₂ O. _Therefore, the value of K ₂ O / Na 2 O is _{K 2 O / Na 2 O ≧} 0.3, preferably 0.34 or more, 0.40 or more, 0.45 or more, 0.50 or more, 0 It is 0.55 or more, particularly preferably 0.7 or more.

However, if the value of K ₂ O/Na ₂ O is too large, the chemical durability such as hydrolysis resistance, acid resistance, and alkali resistance is likely to decrease. _Therefore, the value of K ₂ O / Na 2 O is _{K 2 O / Na 2 O ≦} 1.20, preferably 1.10 or less, less than 1, particularly preferably less than 0.9.

In addition, in the glass composition of the present invention, the Li ₂ O content ratio in R ₂ O is Li ₂ O/(Li ₂ O+Na ₂ O+K ₂ O)≦0.25, and preferably 0.24 or less and 0. It is 20 or less, 0.18 or less, and particularly preferably 0.16 or less.

This makes it possible to increase the depth of the compressive stress layer formed on the glass surface without significantly deteriorating the hydrolysis resistance of the glass. As a result, it is possible to significantly improve the mechanical strength of a drug container such as a vial, ampoule, or syringe.

As described above, Li ₂ O has the effect of lowering the viscosity of glass and improving workability and meltability. However, as the Li 2 _O content in the R 2 _O is large, that is, the content of K _{2 O} and Na 2 _O is relatively small, the depth of the compressive stress layer is reduced. The content of Li ₂ O is 0.1 to 5%, preferably 1 to 5%, 1 to 4.5%, 2 to 4.5%, and particularly preferably 2.5 to 4%.

Na ₂ O is a component that lowers the viscosity of glass, like Li ₂ O. It is also an essential component when chemically strengthening glass. The content of Na ₂ O is 1 to 11%, preferably 1 to 10%, 1 to 8%, 3 to 7%, and particularly preferably 4 to 7%.

K ₂ O has the effect of increasing the depth of the compressive stress layer when chemically strengthened. The content of K ₂ O is 1 to 11%, preferably 1 to 10%, 1.9 to 8%, 2 to 7.5%, 3 to 7%, and particularly preferably 4 to 6%.

MgO, CaO, SrO, and BaO, which are alkaline earth metal oxides (R'O), have an effect of reducing the viscosity of glass. It also affects the amount of alkali elution. When these components are contained as a glass composition, when used as a drug container, a very small amount of R'O may be eluted from the glass into the drug, and its carbonate or sulfate may be precipitated, which is not preferable. Therefore, the total amount of R'O is 0 to 10%, preferably 0.1 to 9%, 0.1 to 6%, 1.1 to 5%, and particularly preferably 1.1 to 4.7%. Is.

Here, whether or not R'O carbonate or sulfate is precipitated depends on the solubility of each salt. Specifically, MgO has the highest solubility, followed by CaO, SrO, and BaO in this order. Therefore, MgO is most unlikely to cause salt precipitation, and BaO is most likely to cause salt precipitation. When the contents are the same, the alkali elution amount from the glass increases in the order of MgO, CaO, SrO, and BaO. Therefore, the content of R′O is preferably MgO≧CaO≧SrO≧BaO, and more preferably MgO>CaO>SrO>BaO.

Further, in the present invention, MgO can be contained. In particular, it is preferable to use MgO as an essential component. Specifically, the content of MgO is 0 to 9%, preferably 0.1 to 8.5%, 0.5 to 8%, 1 to 5%, and particularly preferably 1 to 4%.

The content of CaO is 0 to 4%, preferably 0 to 3%, 0.1 to 2%, and particularly preferably 0.1 to 1.5%.

The content of SrO is preferably 0 to 4%, particularly preferably 0 to 1%, and it is preferably not contained if possible. In the present invention, “not containing” means not positively adding and does not exclude inevitable impurities.

The content of BaO is preferably 0 to 4%, particularly preferably 0 to 1%, and if possible, it is preferably not contained.

ZrO ₂ has an effect of improving alkali resistance of glass. However, if the content is too large, the viscosity of the glass increases and the devitrification resistance deteriorates. Although not an essential component in the present invention, when ZrO ₂ is contained, its content is preferably 0 to 2%, particularly 0 to 1.5%.

As the fining agent, one or more kinds of F, Cl, Sb ₂ O ₃ , As ₂ O ₃ , SnO ₂ , Na ₂ SO _{4 and the} like may be contained. In this case, the total content of the standard fining agent is 5% or less in total, preferably 1% or less, and more preferably 0.5% or less.

It may also contain other components not mentioned above. For example, TiO ₂ , Fe ₂ O ₃ , ZnO, P ₂ O ₅ , Cr ₂ O ₃ , PbO, La ₂ O ₃ , WO ₃ , Nb ₂ O ₃ , in order to improve chemical durability, high temperature viscosity, and the like. Y ₂ O ₃ or the like may be added to each of 3%.

If it is desired to color the glass, TiO ₂ and Fe ₂ O ₃ may be added to the batch raw material. In this case, the standard total content of TiO ₂ and Fe ₂ O ₃ is 5% or less, preferably 1% or less, and more preferably 0.5% or less.

Further, as impurities, components such as H ₂ , CO ₂ , CO, H ₂ O, He, Ne, Ar, and N ₂ may be included up to 0.1%. The amount of the noble metal element such as Pt, Rh, and Au mixed in is preferably 500 ppm or less, and more preferably 300 ppm or less.

Further, the glass of the present invention preferably has an alkali resistance of at least class 2 as determined by a test according to ISO695. This means that the amount of mass reduction per unit area in the above test is 175 mg/dm ² or less. A preferable value of the mass reduction amount per unit area is 130 mg/dm ² or less, and particularly preferably 75 mg/dm ² or less. Delamination often occurs when a glass container is filled with and stored with a drug that uses a solution that behaves like strong alkalinity even in the vicinity of neutrality, such as a citric acid or phosphate buffer solution. Alkali resistance of is one index to judge the resistance to delamination. If the amount of mass reduction per unit area is larger than 175 mg/dm ^{2, the} possibility of causing delamination increases.

Here, the reason why the hydrolysis resistance test according to the European Pharmacopoeia, which is widely practiced, is not adopted as the hydrolysis resistance test for glass for pharmaceutical containers is that this test uses B ₂ O ₃ as a main component. This is because the glass composition containing a large amount is targeted.

In the present invention, it is preferable that the hydrolysis resistance in the test according to ISO720 is at least HGA2. Here, the “test according to ISO720” refers to the following test.
(1) A glass sample is crushed in an alumina mortar and classified with a sieve to 300 to 425 μm.
(2) The obtained powder sample is washed with distilled water and ethanol, and dried in an oven at 140°C.
(3) 10 g of the dried powder sample is placed in a quartz flask, 50 mL of distilled water is further added, the lid is closed, and the mixture is treated in an autoclave. The treatment is performed under the treatment conditions that the temperature is raised from 100° C. to 121° C. at a rate of 1° C./min, the temperature is held at 121° C. for 30 minutes, and the temperature is lowered to 100° C. at a rate of 0.5° C./min.
(4) After the autoclave treatment, the solution in the quartz flask is transferred to another beaker, the inside of the quartz flask is washed with 15 mL of distilled water, and the washing solution is also added to the beaker.
(5) Add a methyl red indicator to a beaker and titrate with a 0.02 mol/L hydrochloric acid aqueous solution.
(6) Convert 1 mL of 0.02 mol/L hydrochloric acid aqueous solution into the amount of alkali elution per 1 g of glass, assuming that it corresponds to 620 μg of Na ₂ O.

"The hydrolysis resistance in the test according to ISO720 is at least HGA2" means that the alkali elution amount in Na ₂ O conversion determined in the above test is 527 μg/g or less. In addition, when the measured value obtained above is 62 μg/g or less, “hydrolysis resistance by the test according to ISO720 is HGA1”.

The glass of the present invention preferably has a hydrolysis resistance of at least HGA2 in a test according to ISO720. That is, the preferred amount of alkali elution is 527 μg/g or less, more preferably 200 μg/g or less, 100 μg/g or less, and particularly preferably 62 μg/g or less. When the amount of alkali elution becomes large, when the glass is processed into an ampoule or a vial and the drug is filled and stored, the drug component may be deteriorated by the alkaline component eluted from the glass.

Further, the glass of the present invention preferably has a working point of 1260°C or lower, preferably 1255°C or lower, and particularly preferably 1250°C or lower. When the working point becomes hot, the working temperature when working the dough tube into an ampoule or a vial becomes higher, and the evaporation of the alkaline component contained in the glass significantly increases. The evaporated alkali component adheres to the inner wall of the dough tube, and the dough tube is processed into a glass container. Such a glass container causes deterioration of the drug when the drug is filled and stored. Further, in a glass containing a large amount of boron, evaporation of boron also occurs, which may cause delamination.

By subjecting the glass for pharmaceutical containers of the present invention to a chemical strengthening treatment, a compressive stress layer having a large stress value and a large depth can be formed on the surface thereof. Specifically, the compressive stress value of the compressive stress layer formed when the ion exchange treatment is performed in KNO ₃ molten salt at 475° C. is 300 MPa or more, 350 MPa or more, 380 MPa or more, 400 MPa or more, 410 MPa or more, 420 MPa or more, It is preferably 430 MPa or more, particularly 450 MPa or more, and the depth of the compressive stress layer is 10 μm or more, preferably 30 μm or more, 40 μm or more, 45 μm or more, 50 μm, 55 μm or more, 60 μm or more, and particularly 61 μm or more.

Next, a method for producing the glass tube for a pharmaceutical container of the present invention will be described. The following description is an example using the Dunner method.

First, glass raw materials are mixed to prepare a glass batch. Next, this glass batch was continuously charged into a melting kiln at 1550 to 1700° C. to perform melting and refining, and then air was blown from the tip of the refractory while winding the obtained molten glass around the rotating refractory. At the same time, the glass is pulled out in a tubular shape from the tip.

Subsequently, the drawn glass tube is cut into a predetermined length to obtain a glass tube for a drug container. The glass tube thus obtained is used for manufacturing vials and ampoules.

The pharmaceutical glass tube of the present invention is not limited to the Dunner method, and may be manufactured by any conventionally known method. For example, the bellows method or the downdraw method is effective as the method for producing the glass tube for a pharmaceutical container of the present invention.

Furthermore, a drug container such as an ampoule or a vial obtained by using the glass tube of the present invention is immersed in KNO ₃ molten salt for ion exchange to obtain a chemically strengthened drug container.

Hereinafter, the present invention will be described based on examples.

Table 1 has shown the Example (sample No. 1-8) and comparative example (sample No. 9-11) of this invention.

Each sample was prepared as follows.

First, a batch of 500 g was prepared so as to have the composition shown in the table, and melted at 1650° C. for 3.5 hours using a platinum crucible. In addition, in order to reduce bubbles in the sample, stirring was performed twice in the melting process. After melting, an ingot was produced, processed into a shape required for measurement, and subjected to various evaluations. The results are shown in each table.

As is clear from Table 1, the sample No. which is an example of the present invention. In Nos. 1 to 8, the working point was 1259° C. or lower, the alkali elution amount by the hydrolysis resistance test was 58 μg/g or less, and the alkali elution amount by the alkali resistance test was 57 mg/dm ² or less. The depth of the compressive stress layer formed during ion exchange was 57 μm or more. In the present invention, it is possible to obtain glass having a deep compression stress layer while having excellent hydrolysis resistance and alkali resistance. In particular, it is possible to increase the depth of the compressive stress layer by regulating the values of K ₂ O/Na ₂ O and Li ₂ O/(Li ₂ O+Na ₂ O+K ₂ O) together. Further, since Li ₂ O is contained as an essential component, the viscosity is low and the workability is excellent.

The strain point Ps was measured by using a fiber drawing method in accordance with ASTM C336, and the temperature at which the glass had a viscosity of 10 ^14.5 Pa·s was determined.

The annealing point Ta was measured by a fiber drawing method according to ASTM C388, and the temperature at which the viscosity of the glass reached 10 ^7.6 dPa·s was determined.

The softening point Ts is a value measured based on the method of ASTM C338.

The working point was measured by using a platinum ball pulling method, and the temperature at which the viscosity of the glass reached 10 ^4.0 dPa·s was determined.

The alkali resistance test was carried out by a method according to ISO695. The detailed test procedure is as follows. A glass sample piece having a surface area A cm ² (where A is 10 to 15 cm ² ) with all surfaces mirror-finished is prepared. First, as a pretreatment, the sample is hydrofluoric acid (40 wt%) and hydrochloric acid (2 mol/L). Was soaked in a mixed solution at a volume ratio of 1:9, stirred with a magnetic stirrer for 10 minutes, then taken out, subjected to ultrasonic cleaning with ultrapure water for 2 minutes 3 times, and then with ethanol for 1 minute. Ultrasonic cleaning was performed twice. Then, the sample was dried in an oven at 110° C. for 1 hour and allowed to cool in a desiccator for 30 minutes. The mass m1 of the sample was measured to an accuracy of ±0.1 mg and recorded. 800 mL of a solution prepared by mixing a sodium hydroxide aqueous solution (1 mol/L) and a sodium carbonate aqueous solution (0.5 mol/L) in a volume ratio of 1:1 was placed in a stainless steel container and boiled with a mantle heater. After that, a sample hung with a platinum wire was put therein and held for 3 hours. The sample was taken out, ultrasonically cleaned with ultrapure water for 2 minutes 3 times, and then ultrasonically cleaned with ethanol for 1 minute 2 times. Then, the sample was dried in an oven at 110° C. for 1 hour and allowed to cool in a desiccator for 30 minutes. The mass m2 of the sample was measured to an accuracy of ±0.1 mg and recorded. From the masses m1 and m2 (mg) before and after being added to the boiling alkaline solution and the surface area A (cm ² ) of the sample, the amount of mass reduction per unit area was calculated by the following calculation formula, which was taken as the measured value of the alkali resistance test. ..
(Amount of mass reduction per unit area)=100×(m1-m2)/A

The compressive stress value (CS) after chemical strengthening (ion exchange) and the depth (DOL) from the sample surface were measured as follows. First, both surfaces of the sample were mirror-polished and then immersed in KNO ₃ molten salt at 475° C. for 7 hours for chemical strengthening (ion exchange treatment). Then, after the surface of the sample is washed, the compressive stress value (CS) of the compressive stress layer on the surface and the sample are determined from the number of interference fringes observed using a surface stress meter (FSM-6000 manufactured by Toshiba Corporation) and the intervals thereof. The depth from the surface (DOL) was calculated. In the calculation, the refractive index of the sample was 1.50 and the photoelastic constant was 29.5 [(nm/cm)/MPa]. Although the glass composition in the surface layer of the glass is microscopically different before and after the strengthening treatment, when viewed as the whole glass, the glass composition is not substantially different.

The hydrolysis resistance test was carried out by a method according to ISO720. The detailed test procedure is as follows. The glass sample was crushed in an alumina mortar using an alumina pestle and classified with a sieve to a particle size of 300 to 425 μm. The obtained powder was washed with ion-exchanged water and ethanol, and dried in an oven at 140°C. 10 g of the dried powder sample was placed in a quartz flask, and 50 mL of ion-exchanged water was further added to cover the lid. A quartz flask containing the sample was placed in an autoclave for processing. The treatment condition was that the temperature was raised from 100° C. to 121° C. at 1° C./min, held at 121° C. for 30 minutes, and then lowered to 100° C. at 0.5° C./min. The solution in the quartz flask was transferred to another beaker, and the inside of the quartz flask was washed 3 times with 15 mL of ion-exchanged water, and the washing water was also added to the beaker. Methyl red indicator was added to the beaker and titrated with 0.02 mol/L hydrochloric acid solution. The amount of alkali elution was calculated by converting 1 mL of the 0.02 mol/L hydrochloric acid solution into 620 μg of Na ₂ O, and used as the measured value of hydrolysis resistance.

The glass for a pharmaceutical container of the present invention is suitable as a glass for producing a pharmaceutical container such as an ampoule, a vial, a prefilled syringe and a cartridge.

Claims (9)

In _{mol%, SiO 2 69~81%,} Al 2 O 3 4~12%, B 2 O 3 0~5%, Li 2 O + Na 2 O + K 2 O 5~20%, Li 2 O 0.1~5% , Na ₂ O 1-11%, K ₂ O 1-11%, MgO+CaO+SrO+BaO 0-10% , ZrO ₂ 0-2%, and a molar ratio K ₂ O/Na ₂ O≧0.3, a molar ratio. Li ₂ O/(Li ₂ O+Na ₂ O+K ₂ O)≦0.25, Glass for pharmaceutical containers. In _{mol%, SiO 2 69~81%,} Al 2 O 3 4~12%, B 2 O 3 0.01~5%, Li 2 O + Na 2 O + K 2 O 5~20%, Li 2 O 0.1~ 5%, Na ₂ O 1-11%, K ₂ O 1-11%, MgO+CaO+SrO+BaO 0-10% , ZrO ₂ 0-2%, and a molar ratio K ₂ O/Na ₂ O≧0.34, The glass for pharmaceutical containers according to claim 1, wherein a molar ratio of Li ₂ O/(Li ₂ O+Na ₂ O+K ₂ O)≦0.25 is satisfied. Pharmaceutical container glass according to claim 1 or 2, characterized in that it contains 0.01～4Mol% to ₂ O ₃ B. Glass for pharmaceutical containers according to any one of claims 1 to 3, which contains MgO 0 to 9%, CaO 0 to 4%, SrO 0 to 4%, and BaO 0 to 4 % in mol %. The glass for a pharmaceutical container according to any one of claims 1 to 4, wherein alkali resistance according to a test according to ISO695 is at least class 2. The working point is 1260°C or lower, and the glass for pharmaceutical containers according to any one of claims 1 to 5. It is characterized in that a compressive stress value of a compressive stress layer formed when an ion exchange treatment is carried out for 7 hours in KNO ₃ molten salt at 475° C. is 300 MPa or more and a depth of the compressive stress layer is 40 μm or more. The glass for pharmaceutical containers according to any one of claims 1 to 6. A glass tube for drug containers, comprising the glass for drug containers according to any one of claims 1 to 7. The glass tube for a pharmaceutical container according to claim 8, wherein the compressive stress value of the compressive stress layer is 300 MPa or more, and the depth of the compressive stress layer is 40 μm or more.