glass tube

Abstract

To provide an improved glass tube, especially, to provide a glass tube providing the improvement of accuracy in a hot molding process and / or the simplified optimization of parameters.SOLUTION: A glass tube, especially, a glass tube for manufacturing a container for storing a pharmaceutical composition, a method for manufacturing the same, and the use thereof are provided. The glass tube capable of easily manufacture, especially, a high quality medicine container has an orientation wall thickness deviation of 8% or less; the orientation wall thickness deviation is specified on the basis of the minimum and maximum wall thickness values measured in the cross section of the glass tube; and the orientation wall thickness deviation WTD is calculated by the following formula.SELECTED DRAWING: Figure 5

Description

[Technical Field]

[0001] The present invention relates to glass tubes, particularly glass tubes for manufacturing containers for storing pharmaceutical compositions. The glass tubes facilitate the manufacture of high-quality pharmaceutical containers. Furthermore, the present invention relates to a method for manufacturing superior glass tubes. [Background technology]

[0002] The so-called Danner process is often used to manufacture glass tubes, particularly those for pharmaceutical containers, such as ampoules, vials, cartridges, or syringes. In the Danner process, molten glass exiting a melting bath flows onto the outer surface of a rotating tubular body (a so-called Danner mandrel), forming a hollow molten glass body on it. The molten glass is then withdrawn from the mandrel, which acts as a shaping member, towards its front end in a predetermined direction. The internal profile of the glass tube is essentially determined by the external contour near the front end of the mandrel.

[0003] Such glass tubes are semi-finished products for manufacturing the containers for storing pharmaceutical compositions. As disclosed in German Patent Application Publication No. 102018101842 (DE102018101842A1), such glass tubes are typically transformed into containers through a hot forming process using glassworking equipment.

[0004] While conventional glass tubes often exhibit reasonably acceptable uniformity in terms of inner and outer diameter, the accuracy of hot forming still needs improvement. In particular, the hot forming process for manufacturing pharmaceutical containers from glass tubes tends to be difficult to operate stably because a vast number of parameters must be optimized to account for variations in the quality of the hot-formed products. [Prior art documents] [Patent Documents]

[0005] [Patent Document 1] German Patent Application Publication No. 102018101842 [Overview of the project] [Problems that the invention aims to solve]

[0006] The object of the present invention is to provide an improved glass tube, and in particular to provide a glass tube that provides improved accuracy in the hot forming process and / or simplified optimization of parameters. [Means for solving the problem]

[0007] In one embodiment, the present invention relates to a glass tube having an azimuthal wall thickness deviation of 6.0% or less, wherein the azimuthal wall thickness deviation is determined based on the lowest and highest wall thickness values ​​measured within the cross-section of the glass tube, and the azimuthal wall thickness deviation WTD is given by the following formula:

number

[0008] A glass tube having the indicated orientation wall thickness deviation functions well during hot forming. The glass tube has at least one cross section having the indicated orientation wall thickness deviation. In a preferred embodiment, the glass tube has the indicated WTD limit value in any of the analyzed cross sections, preferably over the entire length of the tube. Optionally, the indicated orientation wall thickness deviation is present in at least two cross sections spaced apart from each other along the length of the glass tube. Optionally, two or more cross sections of the glass tube do not exceed the indicated WTD, in which case optionally at least two of the cross sections are spaced apart from each other by at least 0.5 m, more preferably at least 0.75 m, most preferably at least 1.0 m, and particularly preferably up to 1.4 m. In an embodiment, the tube does not exceed the indicated WTD in at least a first cross section and a second cross section, in which case the first cross section is located in a first section of the glass tube, and the second cross section is located in a second or third section of the glass tube. In this embodiment, the orientation wall thickness deviation may be a maximum of 5.0%, a maximum of 4.0%, preferably a maximum of 3.0%, a maximum of 2.5%, and optionally a maximum of 2.0% in a single cross section, in two or more cross sections, or in essentially all cross sections (e.g., at least 75%, at least 90%, or at least 95% of the length of the pipe). In this embodiment, the orientation wall thickness deviation may be at least 0.1% or at least 0.5% in a single cross section, in two or more cross sections, or in essentially all cross sections (e.g., at least 75%, at least 90%, or at least 95% of the length of the pipe).

[0009] Surprisingly, it has been found that the orientation wall thickness deviation of glass tubes can vary significantly from tube to tube and along the longitudinal direction of a single glass tube. These variations in wall thickness impede the manufacturing accuracy of pharmaceutical containers produced from these glass tubes. Optimizing the parameters of the hot forming process to account for orientation wall thickness deviation is particularly difficult. Glass tubes are semi-finished products that can be used to manufacture syringes, vials, ampoules, cartridges, or other pharmaceutical containers. These containers are typically manufactured in a hot forming process. Hot forming involves heating the glass tube to a temperature at which it can be formed into a desired shape. Different amounts of heat are required depending on the mass of the glass tube to be heated to the desired temperature. It is difficult to control the amount of heat used during hot forming because these processes produce pharmaceutical containers at a very high rate. Due to this high production rate, it is almost impossible to control the heat according to the characteristics of the glass tube. In practice, while it is already difficult to account for a predetermined deviation in glass mass along the length of the tube, taking into account directional deviations is far more troublesome, if not impossible, because they occur in the same cross-section of the glass tube, and the tube rotates around its longitudinal axis during hot forming. It has been found that controlling the directional distribution of glass mass is essential to keep the amount of heat used in the manufacture of pharmaceutical containers constant.

[0010] Using the right amount of heat during the hot forming of glass is essential because the viscosity of glass changes dramatically with temperature. Between room temperature and the temperature inside the molten vessel, the viscosity of glass changes by 10 17 The viscosity can change by a factor of two. Therefore, even a slight temperature difference can strongly affect the viscosity of the glass. Different viscosities strongly affect the hot forming of the container. The parameters for hot forming must take this behavior into account. Typically, the Vogel-Fulcher-Tammann (VFT) equation is used to calculate the temperature required to achieve a given viscosity of the glass (see DIN ISO 7884-2:1998-2):

number

[0011] In the VFT equation, η is viscosity, A and B are temperature-independent parameters of the material, T is temperature, and T0 is the Vogel temperature. A, B, and T0 are constant for any given glass.

[0012] It is clear that temperature has a strong influence on viscosity, and that the temperature dependence can be described by a constant in the VFT formula. If the temperature is too low, the glass will have high viscosity, making it difficult to form accurate pharmaceutical containers. If the temperature is too high, the viscosity may become too low, causing deflection and resulting in distorted containers. The specifications focus on the tolerance of the outer diameter of the glass tube, and the orientation wall thickness deviation is ignored. It has been found that glass tubes with lower orientation wall thickness deviations have a more uniform distribution of glass mass in the circumferential direction. These glass tubes function very well in the subsequent manufacturing process of pharmaceutical containers, such as syringes, vials, ampoules, and cartridges.

[0013] In one embodiment, the glass of the glass tube has a B value of at least 4000, at least 4500, or at least 5000. Optionally, the value of B may be 12000 or less, 10000 or less, or 9000 or less. T0 may be at least 1°C, at least 10°C, at least 70°C, or at least 200°C. In one embodiment, T0 is in the range of 250°C or less, or 230°C or less. A may be less than 0, for example, less than -0.5 or less than -1.0. In one embodiment, A is at least -5.0, at least -4.0, or at least -3.5. Preferably, A can reach -5.0 to 0.0, or -4.0 to 0.0. Glass tubes having the low orientation wall thickness deviations and their VFT constants described herein function well in hot forming of containers.

[0014] Optionally, the glass may have the following VFT constants: A: in the range of -5.0 to 0.0, B: in the range of 4000 to 12000, and / or T0: in the range of 1 °C to 250 °C. In one embodiment, A is in the range of -3.0 to -1.0, B is in the range of 4000 to 9000, and / or T0 is in the range of 200 °C to 250 °C. For the glass of the glass tube of the present invention, T g may be in the range of 525 °C to 600 °C.

[0015] The inventors assume that the azimuth wall thickness deviation is due to irregularities in the glass supply mechanism used in the manufacture of the glass tube. In particular, the variation in the vertical position where the glass melt first touches the surface of the mandrel (wetting area) has an impact on the azimuth wall thickness deviation. The mandrel is a very heavy part that rotates around a rotation axis. The rotation is not perfect and has a slight deviation in both the horizontal and vertical directions. The said deviation is very small, for example, a few millimeters or dozens of millimeters, but it is sufficient to cause a significant azimuth wall thickness deviation in the glass tube. It has been found that the vertical deviation has a particularly strong influence on WTD. In this disclosure, "vertical" relates to the direction of gravity, that is, the direction in which the glass melt first flows when leaving the outlet of the supply tank. Regarding the position of the wetting area or the mandrel, "horizontal" relates to a direction perpendicular to the said vertical direction and perpendicular to the tube drawing direction.

[0016] The glass tube having an azimuth wall thickness deviation according to the present invention not only has a very uniform wall thickness but also has a uniform mass distribution of the glass in the circumferential direction. Introducing and monitoring the parameters of the azimuth wall thickness deviation described in the present invention enables optimal, preferably minimal, adjustment of the processing parameters in the subsequent hot forming process for manufacturing pharmaceutical containers from the glass tube, ultimately resulting in improved stability of the pharmaceutical containers and the process.

[0017] As used herein, the term “glass tube” refers to a hollow glass body for manufacturing storage containers for substances for pharmaceutical use, such as ampoules, vials, syringes, and / or cartridges. A glass tube typically has a wall surrounding a lumen and two open ends.

[0018] The glass may be silicate glass, for example, borosilicate glass. The glass tube may consist of glass containing the following oxides in mass percentage (%) of the total amount of glass: SiO250~90 B2O30~20 Al2O3 > 0 ~ 18 Na2O 0~15 K2O 0-5 Li2O 0~2 CaO 0-15 BaO 0~6 ZrO20~5 TiO20~5 Fe2O30~3.

[0019] The choice of glass components affects the temperature dependence of glass viscosity. For example, the addition of a certain amount of SiO2 decreases the value for A in the VFT equation and increases the value for B and T0. The following table summarizes the effect of glass components on the constants of the VFT, where increasing the amount of each glass component results in an increase, "+" indicates an increase, "++" means a significant increase in the constant, "-" indicates a decrease, and "--" means a significant decrease in the constant.

[0020] [Table 1]

[0021] The glass may contain SiO2 in a proportion of at least 50% by mass, preferably at least 55% by mass, more preferably at least 60% by mass, and most preferably at least 65% by mass, relative to the total amount of glass. SiO2 is an important network-forming agent in the glass matrix that affects the properties of the glass. In particular, SiO2 is especially important for the chemical durability of the glass. The SiO2 content in the glass may be up to 90% by mass, preferably up to 85% by mass, and more preferably up to 80% by mass, relative to the total amount of glass. If the SiO2 content is too high, the softening point of the glass may rise significantly.

[0022] In addition to SiO2, the glass may also contain at least one second network-forming agent. The glass may contain B2O3 as a further network-forming agent, which is present in a proportion of at least 3% by mass, preferably at least 4% by mass, and more preferably at least 6% by mass, relative to the total amount of glass. Through its network-forming properties, B2O3 essentially supports the stability of the glass. If the B2O3 content is too low, the required stability in the glass system cannot be guaranteed. Nevertheless, the B2O3 content in the glass is at most 20% by mass, preferably at most 15% by mass, and more preferably at most 12% by mass, relative to the total amount of glass. If the B2O3 content in the glass is too high, the viscosity may decrease significantly, so a decrease in crystallization stability must be accepted.

[0023] Furthermore, the glass may contain aluminum oxide. The addition of aluminum oxide helps improve glass formation and generally supports chemical durability. The proportion of aluminum oxide in the glass may be up to 12% by mass, preferably up to 9% by mass, and more preferably up to 7% by mass, relative to the total amount of glass. In one embodiment, the amount of Al2O3 is less than 6.5% by mass. However, too high an aluminum oxide content leads to an increased tendency to crystallize. Preferably, the amount of aluminum oxide in the glass is at least 1% by mass, more preferably at least 2.5% by mass, and most preferably at least 4% by mass, relative to the total amount of glass.

[0024] The glass may contain alkali metal oxides in an amount of at least 3% by mass, preferably at least 5% by mass, and more preferably at least 6% by mass, relative to the total amount of glass. Both Na2O and K2O may be present in the glass.

[0025] Alkali metal oxides improve the meltability of glass, thereby enabling economical production. During the manufacturing of glass, they act as fluxes. The total amount of alkali metal oxides in glass should not exceed 20% by mass, preferably 13% by mass, and more preferably 10% by mass. Optionally, the amount of alkali metal is less than 8.0% by mass. If the alkali metal oxide content is too high, the weather resistance of the glass may be impaired, and consequently, its range of application may be severely limited.

[0026] Optionally, the ratio RO / R2O of the total mass of alkaline earth metal oxides (e.g., CaO, BaO, SrO, and MgO) to the total mass of alkali metal oxides (e.g., Na2O, K2O, Li2O) is at least 0.10, at least 0.15, or at least 0.20. The minimum value for this ratio helps achieve good hydrolysis resistance without compromising the viscosity profile of the glass.

[0027] The proportion of Na2O in the glass may be at least 3% by mass, preferably at least 5% by mass, and more preferably at least 6% by mass, relative to the total amount of glass. However, the proportion of Na2O in the glass may be limited to a maximum of 15% by mass, preferably a maximum of 10% by mass, and more preferably a maximum of 8% by mass, relative to the total amount of glass.

[0028] The proportion of K2O in the glass may be up to 5% by mass, preferably up to 3% by mass for each component, and more preferably up to 2% by mass or up to 1.5% by mass, relative to the total amount of glass.

[0029] The glass may also contain certain additives in addition to the components described above. These additives may be, for example, alkaline earth metal oxides (e.g., BaO, CaO), which may be added to the glass to manipulate its fluidity and melting properties or chemical durability. Additionally or alternatively, the glass may contain oxides of group d metals, such as iron oxides (FeO, Fe2O3, or Fe3O4). Iron oxides are common impurities in the main components of glass, particularly in sand.

[0030] The proportion of BaO in the glass may be up to 6% by mass, preferably up to 4% by mass for each component, and more preferably 3% by mass, relative to the total amount of glass.

[0031] The proportion of CaO in the glass may be up to 5% by mass, preferably up to 3% by mass for each component, and more preferably up to 2% by mass, relative to the total amount of glass. Optionally, the amount of CaO may be at least 0.5% by mass, or at least 1.0% by mass.

[0032] The proportion of Fe2O3 in the glass may be up to 3% by mass, preferably up to 2% by mass for each component, and more preferably 1.5% by mass, relative to the total amount of glass.

[0033] The aforementioned glass composition may also include titanium dioxide. The TiO2 content in the glass is a maximum of 10% by mass, preferably a maximum of 8% by mass, and more preferably a maximum of 6% by mass, relative to the total amount of glass. A very high TiO2 content may lead to undesirable crystallization of the glass.

[0034] In one embodiment, the glass may comprise, by mass percentage, the following: SiO265~83 B2O30~15 Al2O3 1~13 Na2O 3~13 K2O 0~3 Li2O 0~0.1 CaO 0-8 BaO 0~4.5 ZrO20 ~ 0.1 TiO2O~1 Fe2O30~3.

[0035] The orientation wall thickness deviation is calculated using the minimum and maximum wall thickness values ​​measured at a single cross-section of the glass tube. The "cross-section" is the section perpendicular to the longitudinal axis of the tube. The orientation wall thickness deviation is calculated using the following formula:

number

[0036] As used in this application, the term "wall thickness" refers to the shortest distance between the inner and outer diameters of a glass tube at a given location.

[0037] The orientation wall thickness deviation (WTD) compares the minimum and maximum wall thickness values ​​within a given cross-section. Therefore, a glass tube with a maximum orientation wall thickness deviation of 6.0% has a very uniform wall thickness distribution along its length. Preferably, the indicated limit of the orientation wall thickness deviation applies essentially to all cross-sections of the glass tube. However, it has been found that measuring the orientation wall thickness deviation in several representative cross-sections, for example, one cross-section near one end and another near the other end, is sufficient. In one embodiment, the orientation wall thickness deviation of a glass tube is applied to two or more cross-sections spaced apart from each other along the length of the glass tube.

[0038] In one embodiment, the glass tube has an orientation wall thickness deviation of up to 6.0%, up to 5.0%, up to 4.0%, up to 3.0%, up to 2.8%, up to 2.6%, up to 2.4%, up to 2.2%, or up to 1.5%. In one embodiment, the WTD is at least 0.1% or at least 0.5%.

[0039] In a preferred embodiment, the at least two cross-sections, i.e., the cross-sections in which the orientation wall thickness deviation is identified, are spaced apart from each other by at least 0.5 m, more preferably at least 0.75 m, particularly preferably at least 1 m, and most preferably up to 1.4 m.

[0040] At least one cross section can be located in a first section of the glass tube, and a second cross section can be located in a second or third section of the glass tube. The first section may extend longitudinally from a first end of the glass tube toward a second end of the glass tube and may have a length of one-third of the length of the tube. The third section may extend longitudinally from a second end of the glass tube toward a first end of the glass tube and may have a length of one-third of the length of the tube. The second section may be located between the first and third sections and may have a length of one-third of the length of the tube in the longitudinal direction.

[0041] In one embodiment, the glass tube has a maximum azimuthal wall thickness deviation. The maximum azimuthal wall thickness deviation of the glass tube is the highest azimuthal wall thickness deviation measured in a single glass tube. The maximum azimuthal wall thickness deviation can be determined based on two azimuthal wall thickness deviation values ​​that can be specified, for example, for a first section and a third section of the glass tube, or for a first section and a second section, or for a second section and a third section of the glass tube. In one embodiment, one azimuthal wall thickness deviation value is specified for each of those sections. The maximum azimuthal wall thickness deviation of the glass tube may be based on two or more azimuthal wall thickness deviation values, for example, 4, 5, 6, 7, 8, 9, 10 or more. Each azimuthal wall thickness deviation value can be determined for a given cross-section of the tube. When the azimuthal wall thickness deviation value is determined for more than two cross-sections, the distances between each cross-section and its adjacent cross-sections may be essentially equal or different.

[0042] The maximum orientation wall thickness deviation may be a maximum of 6.0%, 5.0%, 4.0%, 3.0%, 2.8%, 2.6%, 2.4%, 2.2%, or 1.5%. In one embodiment, the maximum WTD is at least 0.1% or at least 0.5%.

[0043] In one embodiment, the glass tube has an average azimuthal wall thickness deviation of up to 6.0%, up to 5.0%, up to 4.0%, up to 3.0%, up to 2.8%, up to 2.6%, up to 2.4%, up to 2.2%, or up to 1.5%. In one embodiment, the average WTD is at least 0.1% or at least 0.5%. The average azimuthal wall thickness deviation can be identified in two or more, three or more, four or more, or five or more cross-sections of the glass tube. In one embodiment, the average azimuthal wall thickness deviation is the arithmetic mean of the measured wall thickness deviation values. For example, the values ​​of three azimuthal wall thickness deviations can be identified, for example, in cross-sections in a first, second, and last section along the length of the glass tube to obtain three separate azimuthal wall thickness deviation values. To identify the average azimuthal wall thickness deviation of the glass tube, the arithmetic mean is calculated by dividing the sum of the individual WTD values ​​by the number of cross-sections measured.

[0044] The glass tubes of this disclosure may have a length of at least 0.50 m, more preferably at least 1.00 m, and particularly preferably at least 1.25 m. The length of the glass tube may be 3.00 m or less, 2.00 m or less, or 1.70 m or less. The present invention provides a glass tube having a desired orientation wall thickness deviation even when the length exceeds 1.00 m. In one embodiment, the length of the glass tube is about 1.5 m.

[0045] As used in this application, the term "outer diameter" refers to the maximum distance between two points on the outer surface of a glass tube, where the two points are connected by a straight line that is perpendicular to and intersects the longitudinal axis of the glass tube.

[0046] As used in this application, the term "inner diameter" refers to the maximum distance between two points on the inner surface of a glass tube, where the two points are connected by a straight line that is perpendicular to and intersects the longitudinal axis of the glass tube.

[0047] In one embodiment of this disclosure, the glass tube has an outer diameter of at least 6.0 mm or at least 10.0 mm. The outer diameter may be 55.0 mm or less, 40.0 mm or less, or 25.0 mm or less. In one embodiment, the outer diameter may be selected between 6 mm and 55 mm, or between 6 mm and 25 mm. The wall thickness may vary between 0.3 mm and 3.5 mm. In one embodiment, the wall thickness is at least 0.5 mm, at least 0.7 mm, or at least 1.0 mm. Optionally, the wall thickness may be 3.5 mm or less, 3.0 mm or less, or 2.0 mm or less. The single values ​​of outer diameter and wall thickness depend strongly on the intended use of the glass tube.

[0048] Glass tubes for pharmaceutical containers, particularly glass tubes for syringes, can have an outer diameter of 6.0 mm to 23.0 mm and / or a wall thickness of 0.75 mm to 2.5 mm. A preferred embodiment has an outer diameter of 6.7 mm to 7.0 mm and a wall thickness of 1.0 mm to 1.2 mm. A more preferred embodiment has an outer diameter of 8.00 mm to 8.30 mm and a wall thickness of 0.8 mm to 1.0 mm. A further preferred embodiment has an outer diameter of 10.0 mm to 11.5 mm and a wall thickness of 1.0 mm to 1.2 mm. A further preferred embodiment has an outer diameter of 14.0 mm to 15.0 mm and a wall thickness of 1.2 mm to 1.4 mm. A further preferred embodiment has an outer diameter of 16.5 mm to 17.5 mm and a wall thickness of 1.3 mm to 1.5 mm. A further preferred embodiment has an outer diameter of 21.0 mm to 23.0 mm and a wall thickness of 1.4 mm to 1.6 mm.

[0049] Glass tubes for pharmaceutical containers, particularly tubes for cartridges, can have an outer diameter of 8.0 mm to 19.0 mm and a wall thickness of 0.75 mm to 1.4 mm. A preferred embodiment has an outer diameter of 8.5 mm to 8.8 mm and a wall thickness of 0.8 mm to 1.0 mm. A more preferred embodiment has an outer diameter of 10.5 mm to 11.5 mm and a wall thickness of 1.0 mm to 1.2 mm. A further preferred embodiment has an outer diameter of 10.5 mm to 11.5 mm and a wall thickness of 0.75 mm to 0.95 mm. A further preferred embodiment has an outer diameter of 11.0 mm to 12.0 mm and a wall thickness of 0.9 mm to 1.1 mm. A further preferred embodiment has an outer diameter of 13.5 mm to 14.5 mm and a wall thickness of 0.9 mm to 1.2 mm. A further preferred embodiment has an outer diameter of 14.0 mm to 15.0 mm and a wall thickness of 1.2 mm to 1.4 mm. A more preferred embodiment has an outer diameter of 18.0 mm to 18.5 mm and a wall thickness of 1.0 mm to 1.2 mm.

[0050] Glass tubes for pharmaceutical containers, particularly tubes for vials, may have an outer diameter of 6.0 mm to 55.0 mm and a wall thickness of 0.5 mm to 2.5 mm. A preferred embodiment has an outer diameter of 6.5 mm to 9 mm and a wall thickness of 0.5 mm to 1.6 mm. A more preferred embodiment has an outer diameter of 8.5 mm to 16.0 mm and a wall thickness of 0.5 mm to 1.7 mm. A further preferred embodiment has an outer diameter of 14.5 mm to 18.5 mm and a wall thickness of 0.6 mm to 1.7 mm. A further preferred embodiment has an outer diameter of 17.5 mm to 20.5 mm and a wall thickness of 0.6 mm to 1.7 mm. A further preferred embodiment has an outer diameter of 19.5 mm to 25.5 mm and a wall thickness of 0.6 mm to 1.7 mm. A further preferred embodiment has an outer diameter of 22.5 mm to 35.0 mm and a wall thickness of 0.5 mm to 1.8 mm. A further preferred embodiment has an outer diameter of 29.0 mm to 37.0 mm and a wall thickness of 0.9 mm to 1.7 mm. A further preferred embodiment has an outer diameter of 32.5 mm to 45.0 mm and a wall thickness of 1.2 mm to 1.8 mm. A further preferred embodiment has an outer diameter of 40.0 mm to 55.0 mm and a wall thickness of 1.5 mm to 2.2 mm.

[0051] The glass tube for pharmaceutical containers, particularly the tube for ampoules, can have an outer diameter of 8.0 mm to 30.0 mm and a wall thickness of 0.2 mm to 1.0 mm. Preferred embodiments have an outer diameter of 8.5 mm to 16.0 mm and a wall thickness of 0.3 mm to 0.8 mm. Further preferred embodiments have an outer diameter of 14.5 mm to 18.5 mm and a wall thickness of 0.35 mm to 0.85 mm. Further preferred embodiments have an outer diameter of 17.5 mm to 20.5 mm and a wall thickness of 0.45 mm to 0.85 mm. Further preferred embodiments have an outer diameter of 19.0 mm to 26.0 mm and a wall thickness of 0.55 mm to 0.9 mm.

[0052] The glass tube of the present invention has an inner diameter. The inner diameter may be at least 3. mm, at least 4.0 mm, or at least 8.0 mm. In one embodiment, the inner diameter may be 50.0 mm or less, 40.0 mm or less, 30.0 mm or less, or 20.0 mm or less.

[0053] In one embodiment, the glass tube of the present disclosure has an average linear thermal expansion coefficient (CTE) of 3.0 to 8.0×10 -6 K -1 , or 3.5 to 7.0×10 -6 K -1 , or 4.0 to 6.0×10 -6 K -1 having. Optionally, the CTE is less than 5.2×10 -6 K -1 , or less than 5.1×10 -6 K -1 . It is beneficial for the glass tube to have a lower CTE. Glass with a low CTE tends to generate less stress during hot forming, which results in a more uniform product. Thus, in a preferred embodiment, the CTE is 6.9×10 -6 K -1 or less, or 5.9×10 -6 K -1 or less. The CTE can be measured in accordance with DIN ISO 7991:1987.

[0054] In a further embodiment, the glass of the glass tube has a refractive index n d It has a refractive index of 1.45 to 1.55, more preferably 1.49 to 1.50, or 1.52 to 1.53.

[0055] The density of the glass tube is preferably 1.8 to 3.0 g·cm³. -3 , more preferably 2.0~2.8 g·cm -3 , and most preferably 2.2-2.6 g·cm -3 That is the case.

[0056] In one embodiment of the present disclosure, the outer surface of the glass tube has a protective coating that protects the glass tube from scratches. The protective coating is preferably removable by thermal decomposition occurring at high temperatures. The coating material may include polysorbate, preferably polysorbate 80.

[0057] In one embodiment, the present invention provides a set of glass tubes wherein at least 90% of the tubes have an orientation wall thickness deviation of 8.0% or less, a maximum of 5.0%, a maximum of 4.0%, a maximum of 3.0%, a maximum of 2.5%, or a maximum of 2.0%. In one embodiment, the present invention provides a set of glass tubes wherein at least 90% of the tubes have an average orientation wall thickness deviation of 8.0% or less, a maximum of 5.0%, a maximum of 4.0%, a maximum of 3.0%, a maximum of 2.5%, or a maximum of 2.0%. In one embodiment, the present invention provides a set of glass tubes wherein at least 90% of the tubes have a maximum orientation wall thickness deviation of 8.0% or less, a maximum of 5.0%, a maximum of 4.0%, a maximum of 3.0%, a maximum of 2.5%, or a maximum of 2.0%. The set of glass tubes may include at least 100, or at least 1,000, or at least 3,000 glass tubes, more preferably at least 5,000 glass tubes. In one embodiment, the set is a set of 100, 150, or 200 glass tubes.

[0058] In one embodiment, the present invention relates to a method for manufacturing a glass tube, - A step in which molten glass is applied to the outer surface of a rotating conical mandrel by guiding it from a supply tank through an outlet, where the molten glass forms strands of molten glass flowing from the outlet onto the outer surface of the mandrel. - The step of forming a hollow glass molten body on the conical mandrel, - The step of drawing the hollow glass molten body out of the conical mandrel toward the front end in a predetermined direction to form a glass tube, The outer surface has a wetted region where the glass strands first come into contact with the conical mandrel, where the wetted region is located perpendicularly away from the outlet, and where the vertical movement of the mandrel is monitored. • A step to reduce the vertical movement of the mandrel, • The step of cooling the aforementioned hollow glass molten body, • The step of cutting the cooled molten glass into glass tubes of the desired length. The present invention provides the manufacturing method, which includes the above.

[0059] Reducing the variation in vertical motion may include moving the mandrel vertically to counteract the aforementioned motion. Monitoring the mandrel motion may include monitoring the wetted area. Reducing the mandrel motion may include reducing the motion of the wetted area. The mandrel motion can be achieved by mechanical means known to those skilled in the art.

[0060] Additionally or alternatively, the wetted area may be located horizontally away from the outlet. Its horizontal position may vary during the process. The method may include a step of reducing the variation in horizontal position by arbitrarily moving the mandrel horizontally to counteract the variation. The horizontal movement may be essentially perpendicular to the direction of pipe withdrawal.

[0061] The horizontal and / or vertical movement of the wetted area can be monitored, for example, by one or more cameras and / or one or more lasers or other optical means. Preferably, the movement is monitored in a non-contact manner. For example, the movement of the mandrel can be recorded over time. The recorded horizontal and / or vertical movement can then be plotted and analyzed (e.g., Figure 4).

[0062] This data can be used to control a device that can counteract the horizontal and / or vertical movement of the mandrel.

[0063] Therefore, spatial constancy of the mandrel with respect to the outlet of the molten glass (i.e., the spout) can be achieved. This spatial constancy provides optimal conditions for achieving a highly uniform hollow molten glass, resulting in a glass tube with minimal wall thickness deviation, preferably up to 6.0% along the azimuthal direction. The inventors assume that by keeping the position of the mandrel essentially constant, the rate and amount of molten glass reaching the body will be constant. This allows for a highly homogeneous distribution of the molten glass on the mandrel.

[0064] The hollow molten glass is drawn out of the tubular body toward the front end in a predetermined direction. Preferably, compressed air is blown through the tubular body to prevent the hollow molten glass from collapsing. A so-called drawing valve (called "Ziehzwiebel" in German) is formed at the front end of the mandrel, from which the glass tube is formed by hot forming. The formed glass tube can then be drawn out along the line of support rollers by a drawing device.

[0065] In one embodiment, the rotational speed of the conical mandrel is 5.0–20.0 rpm, 9.0–12.0 rpm, or 9.5–11.0 rpm.

[0066] The inclination of the conical mandrel may be 5° to 45°. In a more preferred embodiment, the volumetric flow rate of the molten glass is 0.4 to 0.55 m³. 3This is per hour. In one embodiment, the temperature of the glass strand in the wet region is 750°C to 1400°C. In one selective embodiment, the withdrawal rate of the hollow glass molten material is 0.1 to 5 m / sec, and optionally 0.3 to 4.0 m / sec.

[0067] In a preferred embodiment, the wetting region is located on the ascending portion of the mandrel surface, rather than on the uppermost point of the mandrel; that is, the molten glass can strike the surface of the mandrel and move upward along it. In other embodiments, the wetting region can be located essentially at the radial uppermost point (0°) of the mandrel, or on the descending portion of the mandrel surface. Optionally, the wetting region may be located in the ascending portion corresponding to -5° to -45°, or -10° to -35°. In another embodiment, the wetting region is located in the descending portion corresponding to +5° to +45°, or +10° to +35°. In yet another embodiment, the wetting region is located at -10° to +10°, or -5° to +5°. It has been found that a wetting region in the ascending portion improves WTD.

[0068] In one embodiment, the vertical distance between the wet area and the outlet is 20 to 250 mm, particularly 50 to 200 mm.

[0069] In other embodiments, the present invention includes glass tubes and / or sets of glass tubes obtained by the methods described herein.

[0070] In one embodiment, the present invention provides the use of a glass tube or set of glass tubes for manufacturing pharmaceutical containers. Preferably, the container is selected from the group consisting of ampoules, vials, syringes and / or cartridges.

[0071] The subject matter of this application will be described in more detail with reference to the following drawings and embodiments, but the subject matter is not limited to the embodiments shown. [Brief explanation of the drawing]

[0072] [Figure 1]This figure shows a schematic cross-sectional view of a manufacturing apparatus for a method according to an embodiment of the present invention. [Figure 2] This figure shows an example of a glass tube 14 having an outer diameter OD, an inner diameter ID, and a wall thickness WT. [Figure 3] This figure shows a cross-section of the glass tube 14. [Figure 4] This figure shows the variation in the vertical movement of the wetted area on the surface of the mandrel. [Figure 5] This is a schematic diagram of a mandrel 6 having a mandrel axis 33. [Figure 6] This is a schematic cross-sectional view of a mandrel having a mandrel axis 33 and a rotation axis 34. [Modes for carrying out the invention]

[0073] Figure 1 shows a schematic cross-sectional view of a manufacturing apparatus for a method according to an embodiment of the present invention.

[0074] The manufacturing apparatus in Figure 1 shows apparatus 1 for drawing glass tubes 2 by the Danner process. Apparatus 1 includes a feed tank 3 containing molten glass 4. In the feed tank 3, the molten glass 4 is typically at a temperature above 1300°C and is applied through an outlet 5 onto the surface of a rotating conical mandrel 6 called a Danner pipe. The Danner pipe can rotate around an axis essentially parallel to the drawing direction.

[0075] As can be deduced from the above figure, the conical mandrel 6 is inclined diagonally downward and is driven by the power unit 7. The molten glass 4 flows from the outlet 5 along the outer surface of the conical mandrel 6, forming a hollow molten glass body 8 thereon. The position where the strands of molten glass first come into contact with the conical mandrel 6 while flowing from the outlet 5 toward the conical mandrel 6 is called the wetting region. The hollow molten glass body 8 is drawn out of the conical mandrel 6 toward the front end in a predetermined direction. Furthermore, compressed air is blown through the conical mandrel 6 to prevent the hollow molten glass body 8 from collapsing. At the front end of the conical mandrel 6, a so-called drawing valve 9 (called "Ziehzwiebel" in German) is formed, and from there the glass tube 2 is manufactured by hot forming.

[0076] The formed glass tube 2 is drawn out by a drawing device 11 located at a distance of 120 m or less from the conical mandrel 6 on the line of support rollers 10, thereby passing the glass tube 2 through a quality control unit 12 that monitors various quality parameters, such as wall thickness and air bubbles. At the end of the line, a cutting device 13 cuts the formed glass tube 2 into individual glass tubes 14.

[0077] The position of the rotating mandrel 6 and / or outlet 5 is continuously monitored and adjusted as appropriate, preferably by using a monitoring device 15, such as one or more cameras or lasers, to compensate for the vibrational movement of the mandrel 6. Reducing or eliminating the vertical and / or horizontal movement of the mandrel can be done by raising or lowering the mandrel and / or by moving the mandrel horizontally to counteract the vertical and / or horizontal movement.

[0078] Figure 2 shows an example of a glass tube 14 having an outer diameter OD, an inner diameter ID, and a wall thickness WT. The azimuthal wall thickness deviation can be measured at a first cross section 25 in a first section of the glass tube, a second cross section 26 in a second section of the glass tube 14, and a third cross section 27 in a third cross section of the glass tube 14. The first cross section 25 can be located at a distance 24 from the first end of the tube. The second cross section 26 can be located at a distance 23 from the first cross section 25. The third cross section 27 can be located at a distance 22 from the second cross section 26. The third cross section 27 can be located at a distance 21 from the second end of the glass tube. Distances 21, 22, 23, and 24 can each be approximately 1 / 4 of the length of the tube. Arbitrarily, distances 22 and 23 are approximately the same length.

[0079] Figure 3 shows a cross-section of the glass tube 14. To determine the orientation wall thickness deviation, two wall thicknesses 31 and 32, i.e., the lowest and highest wall thicknesses in the cross-section, are considered. The orientation wall thickness deviation is calculated from the values ​​of the lowest and highest wall thicknesses using the following formula:

number

[0080] Figure 4 shows the variation in the vertical motion of the wetted area on the surface of the mandrel. The left portion of the figure shows that the vertical position varies by approximately 20 pixels when no measures are taken to reduce the variation in vertical position. The right portion shows the variation measured when measures to reduce the vertical variation are applied, i.e., when the variation is reduced to approximately 10 pixels. One pixel may correspond to, for example, approximately 77 μm.

[0081] Figure 5 is a schematic diagram of a mandrel 6 having a mandrel axis 33. The mandrel 6 rotates around a rotation axis 34. The rotation axis 34 is not the same as the mandrel axis 33, which causes fluctuations in the position of the wetted region 35. Furthermore, the figure shows the distance d from the wetted region 35 to the outlet 5. This distance changes with time (d=f(t)). The position of the wetted region 35 is monitored using a monitoring unit 15, for example, a camera.

[0082] Figure 6 is a schematic cross-sectional view of a mandrel having a mandrel axis 33 and a rotation axis 34. Furthermore, the figure shows the wet region 35 and the outlet 5. The molten glass 4 flows from the outlet 5 into the wet region 35 and is distributed onto the mandrel 6. The theoretical position 36 of the mandrel is shown by a dashed line. The actual position 37 of the mandrel is shown by a solid line. The total displacement 40 of the mandrel position 37 relative to its theoretical position 36 is shown. The total displacement 40 consists of a horizontal displacement 38 and a vertical displacement 39. The position of the wet region 35 is monitored by a monitoring device 15. In this figure, the wet region 35 is not on the top point of the mandrel 6, but on the ascending portion of the mandrel surface, meaning that the molten glass hits the surface of the mandrel and rises upward on the surface. In the figure, its position is between -5° and -45°. In other embodiments, the wetted region 35 may be located at the uppermost point of the mandrel or on the descending portion of the mandrel surface. [Examples]

[0083] Example 1 A glass tube 14 with a length of 1.5 m was manufactured using the Danner process described herein. The glass processed by this method had the following VFT constants: A = -1.41; B = 5047.3; T0 = 224.7°C.

[0084] In a continuous production run, tubes of various diameters were manufactured. Three tubes were selected for WTD evaluation. The orientation wall thickness deviation was determined at three cross-sections along the length of the glass tube 14. The first orientation wall thickness deviation value was determined by measuring the wall thickness deviation at the first cross-section 25 of the glass tube 14, the second value was determined by measuring the wall thickness deviation at the second cross-section 26 of the glass tube 14, and the third value was determined by measuring the wall thickness deviation at the third cross-section 27 of the glass tube 14. The orientation wall thickness deviation (WTD) was calculated for each cross-section. The maximum WTD is the highest WTD measured in each tube.

[0085] [Table 2]

[0086] Example 2 Glass tubes were manufactured using the Danner process, by guiding molten glass from a feed tank through an outlet onto the outer surface of a rotating conical mandrel. During manufacturing, the vertical movement of the mandrel in the wetted area was continuously measured. Vertical movement was reduced by adjusting the mandrel's position. This adjustment was performed by moving the mandrel's suspension up and down to counteract the vertical position fluctuations. As a result, the amplitude of the fluctuations decreased, and the orientation wall thickness deviation improved (Figure 4). The amplitude of the vertical position fluctuation was 20 pixels without compensation and 10 pixels with compensation. This reduction resulted in a 4% decrease in the maximum WTD of the glass tubes. [Explanation of symbols]

[0087] 1 Manufacturing equipment 2 glass tubes 3 tanks 4. Molten glass 5 exit 6 Conical Mandrels 7 Power Unit 8. Glass melt 9. Drawing valve 10 Support rollers 11 Extraction device 12 Quality Control Unit 13 Cutting device 14. Individual glass tubes 15 Monitoring equipment 21 Distance between the second end and the third cross section 22 Distance between the second cross section and the third cross section 23 Distance between the first cross-section and the second cross-section 24 Distance between the first cross section and the first end 25 First cross-section 26. Second cross-section 27 Third Cross Section 31. First wall thickness 32. Second wall thickness 33 Mandrel Axis 34 Rotation axis 35 Wetting area 36 Theoretical Mandrel Position 37. Position of the mandrel 38 Horizontal displacement 39 Vertical displacement 40 Total displacement

Claims

1. A glass tube for manufacturing pharmaceutical containers having an orientation wall thickness deviation of 2.6% or less, wherein the orientation wall thickness deviation is determined based on the minimum and maximum wall thickness values ​​measured within the cross-section of the glass tube, and the orientation wall thickness deviation WTD is given by the following formula: [Math 1] It is calculated according to, The glass of the aforementioned glass tube has the following VFT constants: A: In the range of -5.0 to 0.0, B: A range of 4000 to 12000, and T ０ : Range of 1°C to 250°C The glass tube having the above-mentioned features.

2. The glass tube according to claim 1, wherein the WTD is a maximum of 2.4%, a maximum of 2.2%, or a maximum of 1.5%.

3. The glass tube according to claim 1 or 2, wherein the tube does not exceed the WTD indicated by two or more cross-sections, and at least two of the cross-sections are spaced apart from each other by at least 0.5 m, more preferably at least 0.75 m, most preferably at least 1.0 m, and particularly preferably up to 1.4 m.

4. The glass tube according to any one of claims 1 to 3, wherein the tube does not exceed the WTD indicated by the first cross-section and the second cross-section, and the first cross-section is located in a first section of the glass tube, and the second cross-section is located in a second or third section of the glass tube.

5. The glass tube according to any one of claims 1 to 4, wherein the WTD does not exceed the indicated value in any of the analyzed cross-sections, preferably any cross-section over the entire length of the tube.

6. - Length of at least 0.50 m, at least 1.00 m, or about 1.5 m, • Outer diameter 6.0 mm to 55.0 mm, and / or ・Wall thickness 0.3mm to 3.5mm A glass tube according to any one of claims 1 to 5, having the following:

7. The following ingredients: Yes 2 5p~90 B 2 O 3 0~20 Al 2 O 3 >0~18 Na 2 O0~15 K 2 O 0~5 Li 2 O 0~2 CaO 0-15 BaO 0-6 ZrO 2 0~5 TO 2 0~5 Fe 2 O 3 0~3 A glass tube according to any one of claims 1 to 6, comprising in mass percent (mass%).

8. A method for manufacturing glass tubes, - Molten glass is introduced from a supply tank through an outlet and applied to the outer surface of a rotating conical mandrel, where the molten glass forms strands of molten glass flowing from the outlet onto the outer surface of the mandrel. - The step of forming a hollow glass molten body on the conical mandrel, - The step of drawing the hollow glass molten body out of the conical mandrel toward the front end in a predetermined direction to form a glass tube, - The outer surface has a wetted region where the glass strands first come into contact with the conical mandrel, where the wetted region is located perpendicularly away from the outlet, and the vertical movement of the mandrel is monitored. - A step of reducing the vertical movement of the mandrel, - The step of cooling the hollow glass molten body, - The step of cutting the cooled molten glass into glass tubes of the desired length. The manufacturing method, including the above.

9. The method according to claim 8, wherein reducing the vertical movement of the mandrel includes moving the mandrel in such a way as to counteract the vertical movement.

10. The method according to claim 8 or 9, wherein the wetted area is located horizontally away from the outlet.

11. - A step in which the horizontal position fluctuation is reduced by arbitrarily moving the mandrel in the horizontal direction to cancel out the fluctuation. The method according to claim 10, including the method described in claim 10.

12. A method for manufacturing a glass tube obtained by the method according to any one of claims 8 to 11, having a maximum orientation wall thickness deviation of 6.0%.

13. Use of a glass tube according to any one of claims 1 to 7 for manufacturing a pharmaceutical container.

14. The use according to claim 13, wherein the container is selected from the group consisting of ampoules, vials, syringes, and cartridges.

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