Patent Description:
Glass bottles that are used for pharmaceutical purposes (also known as so-called "vials") are usually prepared from borosilicate glass by hot-forming a borosilicate glass tube. In such a process in a first step the orifice of the vial is formed from the open tube end, wherein this orifice often has the form of a rolled-rim. Thereafter the vial bottom is formed and simultaneously the vial is separated from the residual of the glass tube. For the formation of the vial bottom the glass tube is, for example, secured in a vertical position by means of upper and lower clamping chucks and is then rotated around its longitudinal axis. The rotating glass tube in a certain region is heated by one or two separating gas burners until the heated mass of glass becomes deformable. As soon as this temperature is reached, the tube - under continuing rotation and heating by means of the burner - is extended in axial direction by means of a linear downwards movement of the lower chuck. Thereby the tube in the heated region extends under simultaneous tapering of its diameter, so that a constriction region in the form of a glass thread is formed. After the downward movement the constriction region is further heated. In this way the glass tube at the constriction region further contracts by means of the flow pressure of the burner gases so that the glass walls in the heated region melt together and finally the connection between the upper and the lower tube region pulls off. Thus, two tube regions (or sections) with closed ends are generated, wherein the lower tube region is the final vial, and the upper tube region is the residual glass tube from which further vials can be formed.

During the above-described thermal separation of the lower and the upper tube region, a membrane-like bottom is created. In order to provide a bottom thickness that roughly corresponds to the tube wall thickness, the glass in the bottom region has to be kept liquefied under the most massive supply of heat. However, the centrifugal force prevents the glass from penetrating to the centre of the bottom, i. to the centre of rotation. A large part gets stuck at about <NUM>/<NUM> of the bottom radius and forms a typical "ring bead".

Furthermore, when the upper and lower tube regions are drawn apart from each other in the process described above and when in the course of that process a progressive, rotationally symmetrical constriction of the tube occurs until only one thread remains, this tread finally breaks off near its upper end where the gas separation burner are located. The thread essentially falls downwards onto the membrane-like floor in the middle, where it forms an accumulation of glass mass called "the knot". The minimum bottom thickness is usually found between the ring bead and the knot, the thickest part is usually the knot itself.

In addition to the formation of structures such as the "ring bead" and the "knot", further irregular structures such as ultrafine fissures can also be observed on the outside of the glass bottom. Such structures are often the result of bringing the outer surface of the glass bottom of the glass container into contact with molding tools which in a conventional process for producing glass containers are used to finally shape the circular glass bottom while still being in a molten state. The roughness of the surface of the molding tools also effects the structure on the outer surface of the glass bottom.

It has been observed that state of the art glass containers, particularly state of art pharmaceutical vials that have been prepared by means of the conventional process as described above can often only be inspected optically through the glass bottom to an insufficient extent in an optical inspection machine. The reason for this limited inspection capability is - in addition to the lens effect of the glass bottom caused by the bottom indentation - a non-uniform structure of the outer surface of the glass bottom, which leads to undesired light refracting effects. As a consequence of these light refracting effects a large number of results cannot be interpreted by these inspection machines and the corresponding glass containers are therefore ejected from the automated process.

<CIT> discloses a machine for the preparation of glass ampules, wherein the machine comprises a pair of gripping devices for engaging a length of a tubing, means for heating a portion of the length of tubing between the gripping devices and means for effecting relative movement of said devices away from each other axially of the tubing to reduce the cross-sectional area of the heated portion of the tubing. The machine is characterized in that is further comprises means for moving certain of said heating means transversely with respect to the tubing and means for moving others of said heating means in predetermined timed relation to the said movement of the gripping devices in a direction parallel to the axis of the tubing while said gripping devices are moving relative to each other to progressively heat successive increments of the tubing. The relative movement of the heating means while separating the tube under reduction of the cross-sectional allows to control the shape of the neck of the ampule.

<CIT> discloses an automated Process for detecting contaminants in a vial of pharmaceuticals, comprising imaging of at least one container loaded into an optically viewable element, exposing the container to infrared energy, acquiring images derived from the imaging, from at least two wavelength regions, the wavelength regions including Visible, Near infrared. Short Wave Infrared, and Ultraviolet, agitating at least one container, at least one of before, during, or between image acquisition and comparing the images from the different wavelength regions for contrast differences related to the presence of contaminants.

In general, it is an object of the present invention to at least partly overcome a disadvantage arising from the prior art. It is a particular object of the present invention to provide glass containers, preferably pharmaceutical vials, that shows an improved inspection capability through the glass bottom, compared to glass containers known from the prior art. Moreover, the glass containers, preferably the pharmaceutical vials, should be characterized in that they can be inspected in an optical inspection machine with a reduced number of glass containers that are ejected because the result obtained by optical inspection of that glass container cannot be interpreted.

A contribution to at least partly solving at least one, preferably more than one, of the above objects is made by the independent claims. The dependent claims provide preferred embodiments which contribute to at least partly solving at least one of the objects.

A contribution to solving at least one of the objects according to the invention is made by an embodiment <NUM> of a glass container comprising as container parts.

A contribution is also made by an embodiment <NUM> of a plurality of glass containers, each glass container comprising as container parts.

A "plurality of glass containers" in the sense of the present invention preferably comprises at least <NUM> glass containers, preferably at least <NUM> glass containers, more preferably at least <NUM> glass containers, even more preferably at least <NUM> glass containers and most preferably at least <NUM> glass containers. Preferably, the plurality of glass containers comprises at most <NUM> glass container, more preferably at most <NUM> glass containers. Furthermore, the plurality of glass containers preferably has been collected arbitrarily and particularly has not been selected with regard to any property. For example, the plurality of glass containers may be the group of containers which are packed together in a typical transport tray.

If the circular glass bottom of a glass container, particularly the circular glass bottom of a vial, is characterized by an outer surface the contour of which can be fitted in a least square fit with the profile of a sphere having the Radius R with a curvature function as shown above in which the relative standard deviation error (or relative fitting error) Δc/c is less than <NUM>, it has surprisingly been discovered that the inspection capability through the glass bottom can be significantly increased compared to circular glass bottoms of glass containers known from the prior art.

In an embodiment <NUM> of the glass container or the plurality of glass containers according to the invention the glass container or the plurality of glass containers is designed according to its embodiment <NUM>, wherein for the individual values ĥ that have been determined in the range from x = - <NUM> × d2/<NUM> to x = + <NUM> × d2/<NUM> the relative standard deviation error Δc/c is less than <NUM>.

In an embodiment <NUM> of the glass container or the plurality of glass containers according to the invention the glass container or in the plurality of glass containers is designed according to its embodiment <NUM> or <NUM>, wherein for the individual values ĥ that have been determined in the range from x = - <NUM> × d2/<NUM> to x = + <NUM> × d2/<NUM> the relative standard deviation error Δc/c is less than <NUM>.

In an embodiment <NUM> of the glass container or the plurality of glass containers, the glass container or the plurality of glass containers is designed according to anyone of its embodiments <NUM> to <NUM>, wherein for the individual values ĥ that have been determined in the range from x = - <NUM> × d2/<NUM> to x = + <NUM> × d2/<NUM> the relative standard deviation error Δc/c is less than <NUM>.

In an embodiment <NUM> of the glass container or the plurality of glass containers, the glass container or in the plurality of glass containers is designed according to anyone of its embodiments <NUM> to <NUM>, wherein for the individual values ĥ that have been determined in the range from x = - <NUM> × d2/<NUM> to x = + <NUM> × d2/<NUM> the relative standard deviation error Δc/c is less than <NUM>.

In an embodiment <NUM> of the glass container or the plurality of glass containers, the glass container or the plurality of glass containers is designed according to anyone of its embodiments <NUM> to <NUM>, wherein the relative standard deviation error Δc/c is less than <NUM>, preferably less than <NUM>, more preferably less than <NUM>, even more preferably less than <NUM>, even more preferably less than <NUM> and even more preferably less than <NUM>.

In an embodiment <NUM> of the glass container or the plurality of glass containers according to the invention the glass container or the plurality of glass containers is designed according to anyone of its embodiments <NUM> to <NUM>, wherein for the wavefront distortion W(ρ,ϕ) of a laser light.

In an embodiment <NUM> of the glass container or the plurality of glass containers according to the invention the glass container or the plurality of glass containers is designed according to anyone of its embodiment <NUM> to <NUM>, wherein for the wavefront distortion W(ρ,ϕ) of a laser light.

In an embodiment <NUM> of the glass container or the plurality of glass containers according to the invention the glass container or the plurality of glass containers is designed according to anyone of its embodiments <NUM> to <NUM>, wherein at least within the range from x = - <NUM> × d2/<NUM> to x = + <NUM> × d2/<NUM> the maximum value for ĥ(x) that the fitted curvature function (I) takes on in that range is ĥ(x)max, ĥ(x)max being in the range from <NUM> to <NUM> when d1 is in the range from <NUM> to <NUM>, ĥ(x)max being in the range from <NUM> to <NUM> when d1 is in the range from <NUM> to <NUM> and ĥ(x)max being in the range from <NUM> to <NUM> when d1 is in the range from <NUM> to <NUM>. ĥ(x) usually reaches its maximum value ĥ(x)max at the centre of the circular glass bottom (x = <NUM>). According to a particular embodiment of the glass container or the plurality of glass containers according to the present invention value ĥ(x)max represents the bottom indentation t.

In an embodiment <NUM> of the glass container or the plurality of glass containers according to the invention the glass container or the plurality of glass containers is designed according to anyone of its embodiments <NUM> to <NUM>,.

In an embodiment <NUM> of the glass container or the plurality of glass containers according to the invention the glass container or the plurality of glass containers is designed according to its embodiment <NUM>, wherein the <NUM> % quantile of the values that have been determined for the term <MAT> within a circle having a radius of <NUM> × d2/<NUM> and a centre that corresponds to the centre of the glass bottom is less than <NUM>/mm, preferably less than <NUM>/mm, more preferably less than <NUM>/mm, even more preferably less than <NUM>/mm, even more preferably less than <NUM>/mm, even more preferably less than <NUM>/mm, even more preferably less than <NUM>/mm, even more preferably less than <NUM>/mm and even more preferably less than <NUM>/mm.

In an embodiment <NUM> of the glass container or the plurality of glass containers according to the invention the glass container or the plurality of glass containers is designed according to its embodiment <NUM> or <NUM>, wherein the <NUM> % quantile of the values that have been determined for the term <MAT> within a circle having a radius of <NUM> × d2/<NUM> and a centre that corresponds to the centre of the glass bottom is less than <NUM>/mm, preferably less than <NUM>/mm, more preferably less than <NUM>/mm, even more preferably less than <NUM>/mm, even more preferably less than <NUM>/mm, even more preferably less than <NUM>/mm, even more preferably less than <NUM>/mm, even more preferably less than <NUM>/mm and even more preferably less than <NUM>/mm.

In an embodiment <NUM> of the glass container or the plurality of glass containers, the glass container or the plurality of glass containers is designed according to anyone of its embodiments <NUM> to <NUM>, wherein h(x,y)delta is at least <NUM>, preferably at least <NUM>, more preferably at least <NUM> and even more preferably at least <NUM>.

In an embodiment <NUM> of the glass container or the plurality of glass containers according to the invention the glass container or the plurality of glass containers is designed according to anyone of its embodiments <NUM> to <NUM>, wherein for any cut surface of the circular glass bottom that is obtainable by cutting the circular glass bottom in a plane that includes the longitudinal axis Ltube the following condition is fulfilled: <MAT>.

wherein s2max corresponds to the maximum glass thickness of the circular glass bottom and s2min to the minimum glass thickness of the circular glass bottom as determined within a given cut surface at least within the range from x = - <NUM> × d2/<NUM> to x = + <NUM> × d2/<NUM>, the centre of the circular glass bottom being at position x = <NUM>, wherein s2min and s2max are both measured in a direction that is parallel to the longitudinal axis Ltube.

In an embodiment <NUM> of the glass container or the plurality of containers, the glass container or the plurality of glass containers is designed according to its embodiment <NUM>, wherein s2max and s2min are determined within a given cut surface at least within the range from x = - <NUM> × d2/<NUM> to x = + <NUM> × d2/<NUM>.

In an embodiment <NUM> of the glass container or the plurality of glass containers, the glass container or the plurality of glass containers is designed according to its embodiment <NUM> or <NUM>, whereins2max and s2min are determined at least within a given cut surface within the range from x = - <NUM> × d2/<NUM> to x = + <NUM> × d2/<NUM>.

In an embodiment <NUM> of the glass container or the plurality of containers, the glass container or the plurality of glass containers is designed according to anyone of its embodiments <NUM> to <NUM>, wherein the glass container comprises a top region in which the inner diameter is d4 and a body region in which the inner diameter of the glass tube is d2, wherein d2 > d4 and wherein the glass container comprises a shoulder that connects the body region with the top region. Preferably, the shoulder is characterized by a shoulder angle α, wherein α is in the range from <NUM> to <NUM>°, preferably in the range from <NUM> to <NUM>°, more preferably in the range from <NUM> to <NUM>°, even more preferably in the range from <NUM> to <NUM>° and most preferably in the range from <NUM>° to <NUM>°.

In an embodiment <NUM> of the glass container or the plurality of glass containers, the glass container or the plurality of glass containers is designed according to its embodiment <NUM>, wherein the glass container in the container part from the glass bottom up to the shoulder is rotation-symmetric around the longitudinal axis Ltube that goes perpendicular through the centre of the glass bottom.

In an embodiment <NUM> of the glass container or the plurality of glass containers, the glass container or the plurality of glass containers is designed according to its embodiment <NUM> or <NUM>, wherein d4 is in the range from <NUM> to <NUM>, preferably in the range from <NUM> to <NUM> and more preferably in the range from <NUM> to <NUM>.

In an embodiment <NUM> of the glass container or the plurality of glass containers, the glass container or the plurality of glass containers is designed according to anyone of its embodiments <NUM> to <NUM>, wherein throughout the body region the glass thickness s1 of the glass tube is in a range from ± <NUM>, preferably ± <NUM>, more preferably ± <NUM> and most preferably ± <NUM>, in each case based on a mean value of this glass thickness in the body region.

In an embodiment <NUM> of the glass container or the plurality of glass containers, the glass container or the plurality of glass containers is designed according to anyone of its embodiments <NUM> to <NUM>, wherein d2 is in the range from <NUM> to <NUM>, preferably in the range from <NUM> to <NUM>, more preferably in the range from <NUM> to <NUM>, even more preferably in the range from <NUM> to <NUM> and most preferably in the range from <NUM> to <NUM>.

In an embodiment <NUM> of the glass container or the plurality of glass containers, the glass container or the plurality of glass containers is designed according to anyone of its embodiments <NUM> to <NUM>, wherein s1 is in the range from <NUM> to <NUM>, preferably in the range from <NUM> to <NUM>, more preferably in the range from <NUM> to <NUM>, even more preferably in the range from <NUM> to <NUM> and most preferably in the range from <NUM> to <NUM>.

In an embodiment <NUM> of the glass container or the plurality of glass containers, the glass container or the plurality of glass containers is designed according to anyone of its embodiments <NUM> to <NUM>, wherein the glass container has a mass of glass mg and an interior volume Vi and wherein the following condition is fulfilled: <MAT> preferably <MAT>.

In an embodiment <NUM> of the glass container or the plurality of glass containers, the glass container or the plurality of glass containers is designed according to anyone of its embodiments <NUM> to <NUM>, wherein the glass container has an interior volume Vi in a range from <NUM> to <NUM>, preferably from <NUM> to <NUM>, more preferably from <NUM> to <NUM>, even more preferably from <NUM> to <NUM>, most preferably from <NUM> to <NUM>.

In an embodiment <NUM> of the glass container or the plurality of glass containers, the glass container or the plurality of glass containers is designed according to anyone of its embodiments <NUM> to <NUM>, wherein the glass container has a height h1 in the range from <NUM> to <NUM>, preferably in the range from <NUM> to <NUM>, more preferably in the range from <NUM> to <NUM>, even more preferably in the range from <NUM> to <NUM> and most preferably in the range from <NUM> to <NUM>.

In an embodiment <NUM> of the glass container or the plurality of glass containers, the glass container or the plurality of glass containers is designed according to anyone of its embodiments <NUM> to <NUM>, wherein d1 is in the range from <NUM> to <NUM>, preferably in the range from <NUM> to <NUM>, more preferably in the range from <NUM> to <NUM>, even more preferably in the range from <NUM> to <NUM> and most preferably in the range from <NUM> to <NUM>.

In an embodiment <NUM> of the glass container or the plurality of glass containers, the glass container or the plurality of glass containers is designed according to anyone of its embodiments <NUM> to <NUM>, wherein at least one of the properties of the glass container selected from the group consisting of s1, d1, h1 and t is within the requirements defined in DIN EN ISO <NUM>-<NUM>:<NUM>-<NUM>.

In an embodiment <NUM> of the glass container or the plurality of glass containers, the glass container or the plurality of glass containers is designed according to anyone of its embodiments <NUM> to <NUM>, wherein the glass container is a packaging container for a medical or a pharmaceutical packaging good or both. A preferred pharmaceutical packaging good is a pharmaceutical composition. Preferably, the glass container <NUM> is suitable for packaging parenteralia in accordance with section <NUM>. <NUM> of the European Pharmacopoeia, 7th edition from <NUM>.

In an embodiment <NUM> of the glass container or the plurality of glass containers, the glass container or the plurality of glass containers is designed according to anyone of its embodiments <NUM> to <NUM>, wherein the glass container is a vial.

In an embodiment <NUM> of the glass container or the plurality of glass containers, the glass container or the plurality of glass containers is designed according to anyone of its embodiments <NUM> to <NUM>, wherein the glass is of a type selected from the group consisting of a borosilicate glass, an aluminosilicate glass, soda lime glass and fused silica. "Soda lime glass" according to the invention is an alkaline/alkaline earth/silicate glass according to table <NUM> of ISO <NUM> (<NUM>st edition <NUM>-<NUM>-<NUM>).

In an embodiment <NUM> of the glass container or the plurality of glass containers, the glass container or the plurality of glass containers is designed according to anyone of its embodiments <NUM> to <NUM>, wherein the glass container comprises a pharmaceutical composition.

In an embodiment <NUM> of the glass container or the plurality of glass containers, the glass container or the plurality of glass containers is designed according to anyone of its embodiments <NUM> to <NUM>, wherein the glass container comprises a closure at the top of the glass container, preferably a lid.

A contribution is also made by a process for the determination of a physical property of a material that is contained in a glass container comprising as process step:.

In an embodiment <NUM> of the process, the process is designed according to its embodiment <NUM>, wherein the material is a pharmaceutical composition, preferably a liquid or solid pharmaceutical composition, more preferably a freeze-dried product or a liquid comprising at least one drug dissolved or dispersed therein.

In an embodiment <NUM> of the process, the process is designed according to its embodiment <NUM> or <NUM>, wherein the physical property of the material is determined by radiation in an optical inspection machine, preferably in an automated optical inspection machine.

In an embodiment <NUM> of the process, the process is designed according to anyone of its embodiment <NUM> to <NUM>, wherein the physical property is selected from the group consisting of the transmission, the colour, the refractive index and the absorption at a given wavelength of electromagnetic radiation.

A contribution to solving at least one of the objects according to the invention is also made by the use of a glass container or a plurality of glass containers according to anyone of embodiments <NUM> to <NUM> for determining a physical property of a material contained in the glass container.

The glass container according to the present invention or the glass containers contained in the plurality of glass containers according to the present invention is preferably produced by means of an embodiment <NUM> of a process for the preparation of a glass container from a glass tube in a glass processing machine,.

Surprisingly, it has been discovered that - if at least one separation gas burner follows at least one portion of the glass tube in the separation process - an advantageous bottom geometry of the glass container can be obtained, compared to the bottom geometry obtained in a prior art process in which the separation gas burners remain in a fixed position. The present invention thus simplifies the production of vials by creating the required bottom geometry during the separation process and thereby enables a new, unprecedented quality of the bottom geometry that is ideal for automated inspection processes, both unfilled and filled.

The "softening temperature" of the glass is the temperature at which the glass has a viscosity (determined according to ISO <NUM>-<NUM>:<NUM>) of <NUM><NUM> dPa×sec.

In an embodiment <NUM> of the process for the preparation of a glass container, the process is designed according to its embodiment <NUM>, wherein in process step II) two diametrically opposed separation gas burners are used which are arranged such that the glass tube rotates centrally between the two flames generated by these two separation gas burners.

In an embodiment <NUM> of the process for the preparation of a glass container, the process is designed according to its embodiment <NUM> or <NUM>, wherein the first and second clamping chucks are adapted and arranged to hold the glass tube in a vertical position;.

In an embodiment <NUM> of the process for the preparation of a glass container, the process is designed according to its embodiment <NUM>, wherein in process step III) the lower clamping chucks are moved downwards at a point of time t and the at least one separation gas burner is moved downwards at a point of time t' = t + Δt.

In an embodiment <NUM> of the process for the preparation of a glass container, the process is designed according to its embodiment <NUM>, wherein Δt = <NUM> sec. In this particular embodiment of the process the at least one separation gas burner and the lower clamping chucks (and thus also the lower portion of the glass tube) are moved downwards simultaneously.

In an embodiment <NUM> of the process for the preparation of a glass container, the process is designed according to its embodiment <NUM>, wherein Δt is in the range from <NUM> to <NUM> sec, preferably in the range from <NUM> to <NUM> sec, more preferably in the range from <NUM> to <NUM> sec and even more preferably in the range from <NUM> to <NUM> sec.

In an embodiment <NUM> of the process for the preparation of a glass container, the process is designed according to anyone of its embodiments <NUM> to <NUM>, wherein in process step III) the at least one separation gas burner is moved downwards starting from a position Y'<NUM> to a stop position Y'stop and the lower clamping chucks is moved downwards starting from a position Y<NUM> and, preferably after the at least one separation gas burner has stopped at position Y'stop, to stop at a position Ystop.

In an embodiment <NUM> of the process for the preparation of a glass container, the process is designed according to its embodiment <NUM>, wherein | Y'stop - Y'<NUM>| < | Ystop - Y<NUM>|. According to this embodiment it is thus preferred that the distance with which the at least one separation gas burner is moved downwards is smaller than the distance with which the lower clamping chucks are moved downward.

In an embodiment <NUM> of the process for the preparation of a glass container, the process is designed according to its embodiment <NUM>, wherein (|Y'stop - Y'<NUM>| / |Ystop - Y<NUM>| ) (i. the ratio of the distance with which the burner has been moved downwards to the distance with which the lower clamping chucks have been moved downwards) is in the range from <NUM> to <NUM>, preferably in the range from <NUM> to <NUM>, more preferably in the range from <NUM> to <NUM>, even more preferably in the range from <NUM> to <NUM>, even more preferably in the range from <NUM> to <NUM> and most preferably in the range from <NUM> to <NUM>.

In an embodiment <NUM> of the process for the preparation of a glass container, the process is designed according to anyone of its embodiments <NUM> to <NUM>, wherein the downward movements of the at least one separation gas burner and the lower clamping chucks are independent from each other. In this context it is particularly preferred that the downward movements of the at least one separation gas burner and the lower clamping chucks are accomplished through independent servo drives.

In an embodiment <NUM> of the process for the preparation of a glass container, the process is designed according to anyone of its embodiments <NUM> to <NUM>, wherein the downward movements of the at least one separation gas burner and the lower clamping chucks are both linear synchronous with each other.

In an embodiment <NUM> of the process for the preparation of a glass container, the process is designed according to anyone of its embodiments <NUM> to <NUM>, wherein the distance between the at least one separation gas burner and the upper end of the lower portion is kept constant when the at least one separation gas burner follows the upper end of the lower portion.

In an embodiment <NUM> of the process for the preparation of a glass container, the process is designed according to anyone of its embodiments <NUM> to <NUM>, wherein the outer surface of the upper end of the lower portion does not come into contact with any part of the glass processing machine while the final shape of the circular glass bottom is formed.

In an embodiment <NUM> of the process for the preparation of a glass container, the process is designed according to anyone of its embodiments <NUM> to <NUM>, wherein after process step III) in a further process step IV) the thickness of the glass in the circular glass bottom is equalized by heating the circular glass bottom, while still having a temperature above the glass transition temperature and while still rotating the lower portion of the glass tube around its longitudinal axis Ltube, with at least one bottom shaping gas burner, thereby forming the final shape of the circular glass bottom.

In an embodiment <NUM> of the process for the preparation of a glass container, the process is designed according to anyone of its embodiments <NUM> to <NUM>, wherein after process step III) in a further process step IV) the thickness of the glass in the circular glass bottom is equalized by bringing the outer surface of the circular glass bottom, while still having a temperature above the glass transition temperature and while still rotating the lower portion of the glass tube around its longitudinal axis Ltube, into contact with a molding tool, thereby forming the final shape of the circular glass bottom.

In an embodiment <NUM> of the process for the preparation of a glass container, the process is designed according to anyone of its embodiments <NUM> to <NUM>, wherein after process step III) in a further process step IV) the thickness of the glass in the circular glass bottom is equalized by heating the circular glass bottom, while still having a temperature above the glass transition temperature and while still rotating the lower portion of the glass tube around its longitudinal axis Ltube, with at least one bottom shaping gas burner, followed by a process step of bringing the outer surface of the circular glass bottom, while still having a temperature above the glass transition temperature and while still rotating the lower portion of the glass tube around its longitudinal axis Ltube, into contact with a molding tool, thereby forming the final shape of the circular glass bottom.

In an embodiment <NUM> of the process for the preparation of a glass container, the process is designed according to anyone of its embodiments <NUM> to <NUM>, wherein the process comprises the further process step of.

The glass container according to the invention or the glass container contained in the plurality of glass containers according to the invention may have any size or shape which the skilled person deems appropriate in the context of the invention. Preferably, the top region of the glass container comprises an opening, which allows for inserting a pharmaceutical composition into the interior volume of the glass container. A preferred glass container is a pharmaceutical glass container, more preferably one selected from the group consisting of a vial, an ampoule or a combination thereof, wherein a vial is particularly preferred.

For the use in this document, the interior volume Vi represents the full volume of the interior of the glass container. This volume may be determined by filling the interior of the glass container with water up to the brim and measuring the volume of the amount of water which the interior can take up to the brim. Hence, the interior volume as used herein is not a nominal volume as it is often referred to in the technical field of pharmacy. This nominal volume may for example be less than the interior volume by a factor of about <NUM>.

The following are particularly preferred embodiments of the glass container according to the present invention (or of the glass container contained in the plurality of glass containers according to the present invention). When reference is made to the relative standard deviation error Δc/c, the values for Δc and c are preferably determined by fitting the individual values ĥ(x) that have been obtained within the range from x = - <NUM> × d2/<NUM> to x = + <NUM> × d2/<NUM> with curvature function (I). When reference is made to the <NUM> % quantile of the values that have been determined for the term <MAT> this term has been determined for all given positions x,y within a circular area having a radius of <NUM> × d2/<NUM>. When reference is made to the parameters s2max/s1 × (s2max/s2min - <NUM>), the corresponding value is also preferably determined within the range from x = -<NUM> × d2/<NUM> to x = + <NUM> × d2/<NUM>.

According to a first preferred embodiment of the glass container, the glass container is a vial with an overflow capacity equal to or larger than <NUM> up to maximal <NUM>, preferably a vial with a size designation "2R" according to DIN EN ISO <NUM>-<NUM>:<NUM>-<NUM>, wherein it is furthermore preferred that at least one, preferably all of the following conditions i) to vi) is/are fulfilled:.

According to a second preferred embodiment of the glass container, the glass container is a vial with an overflow capacity of larger than <NUM> up to maximal <NUM>, preferably a vial with a size designation "4R" according to DIN EN ISO <NUM>-<NUM>:<NUM>-<NUM>, wherein it is furthermore preferred that at least one, preferably all of the following conditions i) to vi) is/are fulfilled:.

According to a third preferred embodiment of the glass container, the glass container is a vial with an overflow capacity of larger than <NUM> up to maximal <NUM>, preferably a vial with a size designation "6R" according to DIN EN ISO <NUM>-<NUM>:<NUM>-<NUM>, wherein it is furthermore preferred that at least one, preferably all of the following conditions i) to vi) is/are fulfilled:.

According to a fourth preferred embodiment of the glass container, the glass container is a vial with an overflow capacity of larger than <NUM> up to maximal <NUM>, preferably a vial with a size designation "8R" according to DIN EN ISO <NUM>-<NUM>:<NUM>-<NUM>, wherein it is furthermore preferred that at least one, preferably all of the following conditions i) to vi) is/are fulfilled:.

According to a fifth preferred embodiment of the glass container, the glass container is a vial with an overflow capacity of larger than <NUM> up to maximal <NUM>, preferably a vial with a size designation "10R" according to DIN EN ISO <NUM>-<NUM>:<NUM>-<NUM>, wherein it is furthermore preferred that at least one, preferably all of the following conditions i) to vi) is/are fulfilled:.

According to a sixth preferred embodiment of the glass container, the glass container is a vial with an overflow capacity of larger than <NUM> up to maximal <NUM>, preferably a vial with a size designation "15R" according to DIN EN ISO <NUM>-<NUM>:<NUM>-<NUM>, wherein it is furthermore preferred that at least one, preferably all of the following conditions i) to vi) is/are fulfilled:.

According to a seventh preferred embodiment of the glass container, the glass container is a vial with an overflow capacity of larger than <NUM> up to maximal <NUM>, preferably a vial with a size designation "20R" according to DIN EN ISO <NUM>-<NUM>:<NUM>-<NUM>, wherein it is furthermore preferred that at least one, preferably all of the following conditions i) to vi) is/are fulfilled:.

According to an eighth preferred embodiment of the glass container, the glass container is a vial with an overflow capacity of larger than <NUM> up to maximal <NUM>, preferably a vial with a size designation "25R" according to DIN EN ISO <NUM>-<NUM>:<NUM>-<NUM>, wherein it is furthermore preferred that at least one, preferably all of the following conditions i) to vi) is/are fulfilled:.

According to a ninth preferred embodiment of the glass container, the glass container is a vial with an overflow capacity of larger than <NUM> up to maximal <NUM>, preferably a vial with a size designation "30R" according to DIN EN ISO <NUM>-<NUM>:<NUM>-<NUM>, wherein it is furthermore preferred that at least one, preferably all of the following conditions i) to vi) is/are fulfilled:.

According to a tenth preferred embodiment of the glass container, the glass container is a vial with an overflow capacity of larger than <NUM> up to maximal <NUM>, preferably a vial with a size designation "50R" according to DIN EN ISO <NUM>-<NUM>:<NUM>-<NUM>, wherein it is furthermore preferred that at least one, preferably all of the following conditions i) to vi) is/are fulfilled:.

According to an eleventh preferred embodiment of the glass container, the glass container is a vial with an overflow capacity of larger than <NUM> up to maximal <NUM>, preferably a vial with a size designation "100R" according to DIN EN ISO <NUM>-<NUM>:<NUM>-<NUM>, wherein it is furthermore preferred that at least one, preferably all of the following conditions i) to vi) is/are fulfilled:.

The glass of the container may be any type of glass and may consist of any material or combination of materials which the skilled person deems suitable in the context of the invention. Preferably, the glass is suitable for pharmaceutical packaging. Particularly preferable, the glass is of type I, more preferably type I b, in accordance with the definitions of glass types in section <NUM>. <NUM> of the European Pharmacopoeia, <NUM>th edition from <NUM>. Additionally, or alternatively preferable to the preceding, the glass is selected from the group consisting of a borosilicate glass, an aluminosilicate glass, soda lime glass and fused silica; or a combination of at least two thereof. For the use in this document, an aluminosilicate glass is a glass which has a content of Al<NUM>O<NUM> of more than <NUM> wt. -%, preferably more than <NUM> wt. -%, particularly preferable in a range from <NUM> to <NUM> wt. -%, in each case based on the total weight of the glass. A preferred aluminosilicate glass has a content of B<NUM>O<NUM> of less than <NUM> wt. -%, preferably at maximum <NUM> wt. -%, particularly preferably in a range from <NUM> to <NUM> wt. -%, in each case based on the total weight of the glass. For the use in this document, a borosilicate glass is a glass which has a content of B<NUM>O<NUM> of at least <NUM> wt. -%, preferably at least <NUM> wt. -%, more preferably at least <NUM> wt. -%, more preferably at least <NUM> wt. -%, even more preferably at least <NUM> wt. -%, particularly preferable in a range from <NUM> to <NUM> wt. -%, in each case based on the total weight of the glass. A preferred borosilicate glass has a content of Al<NUM>O<NUM> of less than <NUM> wt. -%, preferably less than <NUM> wt. -%, particularly preferably in a range from <NUM> to <NUM> wt. -%, in each case based on the total weight of the glass. In a further aspect, the borosilicate glass has a content of Al<NUM>O<NUM> in a range from <NUM> to <NUM> wt. -%, preferably in a range from <NUM> to <NUM> wt. -%, in each case based on the total weight of the glass.

A glass which is further preferred is essentially free from B. Therein, the wording "essentially free from B" refers to glasses which are free from B which has been added to the glass composition by purpose. This means that B may still be present as an impurity, but preferably at a proportion of not more than <NUM> wt. -%, more preferably not more than <NUM> wt. -%, in each case based on the weight of the glass.

The following measurement methods are to be used in the context of the invention. Unless otherwise specified, the measurements have to be carried out at an ambient temperature of <NUM>, an ambient air pressure of <NUM> kPa (<NUM> atm) and a relative atmospheric humidity of <NUM> %.

The distance between the outer surface of the circular glass bottom and the ground is determined by means of non-contact profilometer (cyberSCAN CT <NUM>; cyberTECHNOLOGIES, Eching-Dietersheim, Germany) and a chromatic sensor (Precitec CHRocodile S <NUM>) using the ASCAN software. As shown in <FIG>, for the determination of the individual values for ĥ, for any given circle the centre of which corresponds to the centre of the glass bottom the distance h between contact plane representing the ground and the outer surface of the circular glass bottom is determined in regularly steps of <NUM>° (i. <NUM> measuring points per circle), serving as data points for an azimuthal average. For a more precise measurement, the <NUM> single measuring points are defined as the moving average of additional measuring points (i. five additional measuring points are averaged to obtain a single measuring point) along the same circle. The first circle is a circle having a diameter of <NUM> and the radius increases for the following circles stepwise by <NUM> (which means that the radius of the second circle is <NUM>,<NUM>, the radius of the third circle is <NUM>,<NUM> and so on).

In order to characterize the mean curvature of the glass bottom, the height function (I) <MAT> is fitted to at least four nodes Hi(xi) of the radial height profile using a common least square fitting, implemented in standard mathematical software packages, e.g. the "curve_fit" function of the open source scipy. optimize package:
https://docs. org/doc/scipy/reference/generated/scipy.

For the fit the variable parameters are c and h<NUM> are used. These variables are varied to obtain the minimum of <MAT> wherein standard deviation error (or fitting error) for constant c is referred to as "Δc". The standard deviation error is defined as <MAT> (σ<NUM> being the variance).

The curvature c directly affects imaging through the glass bottom. The offset height h<NUM> depends on the reference system. In the case of referencing to the standing area, the offset height h<NUM> ≈ t (but only in rare cases equal).

The two-dimensional distance between the outer surface of the circular glass bottom and the ground is again determined by means of a non-contact profilometer (cyberSCAN CT <NUM>; cyberTECHNOLOGIES, Eching-Dietersheim, Germany) and a chromatic sensor (Precitec CHRocodile S <NUM>). For the determination of the h(x,y)-values, the glass bottom is divided into an array of square parts <NUM> having an edge length of <NUM> as shown in <FIG>. At the centre of each of these square parts <NUM> the distance between the outer surface <NUM> of the glass bottom <NUM> and the ground is determined for individual measurement points <NUM> that are located in the centre of the square parts <NUM> as shown in <FIG>. From the thus obtained values h(x,y) only those values are selected that have been obtained for measurement points <NUM> that are located within a circle having a radius of <NUM> × d2/<NUM> (or a radius of <NUM> × d2/<NUM> or <NUM> × d2/<NUM>) as shown in <FIG>.

From the thus obtained h(x,y)-values the slope-values are calculated using an appropriate mathematical software, for example the "Slope Analysis" function of the Mx software version <NUM>. <NUM> (Zygo, part of AMETEK, Inc. The slope magnitude can be calculated as <MAT>.

For this calculation with the Mx software a slope lateral resolution as well as integration length of the edge length of the square parts <NUM> can be used, here <NUM>. The h(x,y)max-value corresponds to the highest h(x,y)-value and the h(x,y)min-value corresponds to the lowest h(x,y)-value that have been determined within the circle having a radius of <NUM> × d2/<NUM> (or a radius of <NUM> × d2/<NUM> or <NUM> × d2/<NUM>).

A polar coordinate system is used to fit a continuous wavefront W(ρ,ϕ) to the measured nodes Wi. The wavefront is defined on the unit circle, thus ρ = <NUM> corresponds to <MAT>.

With 2W < A < (2W+<NUM>) and A being the measurement diameter of the Shack-Hartmann sensor. This continuous wavefront can again be expressed in Zernike terms by a superposition of Zernike polynomials (described by <NPL>) as <MAT>.

Here the coefficients ai have been computed with the inner product <MAT> where p has been integrated from <NUM> to <NUM> and ϕ from <NUM> to 2p. We define the corrected wavefront distortion W(ρ,ϕ)corrected <MAT> as the wavefront with piston (Z<NUM>), tilt (Z<NUM>,Z<NUM>) and defocus (Z<NUM>) subtracted. The OSA/ANSI indexing conventions as described in Thibos et al. A setup to measure the wavefront distortion W(ρ,ϕ) is shown in <FIG>.

The measurement of the thickness of the circular glass bottom was performed using a CHRocodile M4 high resolution measuring head (Precitec GmbH & Co. KG, Lemgo, Germany) with a measuring range of <NUM> - <NUM> and a resolution of <NUM>. A step width of <NUM> was selected laterally.

The wall thickness s1 of the glass container at a given position as well as the outer diameter (d1) of the glass container at a given position are determined in accordance with DIN ISO <NUM>-<NUM>:<NUM>-<NUM>. The inner diameter (d2) can be calculated from s1 and d1.

A glass tube (Fiolax® clear, Schott AG, Germany) having an outer diameter d1 of <NUM> and a wall thickness s1 of <NUM> is loaded into the head of a rotary machine. While rotating around its major axis the glass tube is heated to its softening point with two separation gas burners as shown in <FIG> and the heated glass is pulled along its major axis by moving downwards the lower clamping chucks for stretching and creating a container closure in the form of a circular glass bottom. When moving downwards the lower clamping chucks, the separation gas burners are moved in the same direction as the lower clamping chucks. The ratio of the distance with which the separation gas burners have been moved downwards to the distance with which the lower clamping chucks have been moved downwards (| Y'stop - Y'<NUM>| / | Ystop - Y<NUM>|; see <FIG>) was <NUM>. Furthermore, the burner was moved downwards with a time offset (Δt) of <NUM> sec. In a Comparative Example representing the prior-art process the burner remains at a fixed position when the lower clamping chucks are moved downwards. The glass containers prepared as described above are characterized by a volume of <NUM>.

As can be seen, adjusting the outer contour of the circular glass bottom in order to ensure that the relative standard deviation error Δc/c is below <NUM> significantly improves the optical inspection capability of the glass container.

Unless otherwise specified in the description or the particular figure:.

<FIG> shows a cross-sectional view of a glass container according to the invention, wherein for the purpose of an improved illustration the parts of the glass container (i. glass tube <NUM>, glass bottom <NUM> and curved glass heel <NUM>) have been separated from each other. The glass container <NUM> comprises a glass tube <NUM> with a first end <NUM> and a further end <NUM>, the glass tube <NUM> having an outer diameter d1, an inner diameter d2 and a wall thickness s1. The glass tube <NUM> is further characterized by a longitudinal axis Ltube that passes through the centre of the first end <NUM> and the further end <NUM>. The glass tube further comprises a circular glass bottom <NUM>, wherein the circular glass bottom <NUM> closes the glass tube <NUM> at the first end <NUM>, wherein the circular glass bottom <NUM> comprises an inner surface <NUM> directed to the inside of the glass container <NUM>, an outer surface <NUM> directed to the outside of the glass container <NUM> and a centre <NUM>. The glass container further comprises a curved glass heel <NUM> extending from an outer end <NUM> of the circular glass bottom <NUM> to the first end <NUM> of the glass tube <NUM>. As can also be seen in <FIG>, the glass bottom is preferably characterized by a bottom indentation t which usually takes on the maximum value in the centre <NUM> of the circular glass bottom <NUM>. <FIG> shows a glass container <NUM> in which the individual container parts shown in <FIG> (i. glass tube <NUM>, glass bottom <NUM> and curved glass heel <NUM>) are arranged in the usual way.

<FIG> show a cross-sectional view of the bottom area of a glass container <NUM> according to the invention and illustrate the different areas (x ± <NUM> × d2/<NUM> in <FIG>, x ± <NUM> × d2/<NUM> in <FIG> and x ± <NUM> × d2/<NUM> in <FIG>) in which the distance h between a contact plane <NUM> and the outer surface <NUM> of the circular glass bottom <NUM> at a given position x, with x = <NUM> in the centre <NUM> of the circular glass bottom <NUM>, is determined. The individual values of h can be applied to determine ĥ and ĥ(x).

<FIG> shows the arrangement of concentrical circles <NUM> along which the individual values for ĥ are determined. As shown in <FIG>, for the determination of the individual values for ĥ, for any given circle the distance h between contact plane <NUM> representing the ground on which the glass container <NUM> rests and the outer surface <NUM> of the circular glass bottom <NUM> is determined in regularly steps of <NUM>° (i. <NUM> measuring points per circle; for the sake of clarity only <NUM> steps are shown in <FIG>), serving as data points for an azimuthal average. The first circle <NUM> is a circle having a diameter of <NUM> and the radius increases for the following circles stepwise by <NUM> (which means that the radius of the second circle is <NUM>,<NUM>, the radius of the third circle is <NUM>,<NUM> and so on).

From the thus obtained values for h the azimuthal average corresponds to the individual value ĥ that has been determined for any given circle <NUM>. <FIG> shows a graph of the individual values for ĥ that have been determined for a given circular glass bottom <NUM> and the fitted function ĥ(x) (see the dashed line). The fitted function is represented by formula (I) <MAT> in which c and h<NUM> serve as individual fitting parameters. The above function is the curvature function of a sphere having the radius R with c = <NUM>/R. Values for c (and also for the standard deviation error (Δc) indicating how exactly the determined individual values of ĥ can be reproduced using the curvature function given above) are determined using an appropriate mathematical software (ASCAN-Software) as described in the "Test method"-section above.

<FIG> show the experimental setup that has been used to determine the two-dimensional distance h(x,y) and the slope magnitude <MAT> of the outer surface <NUM> of the glass bottom <NUM> at a given position x,y. The distance h(x,y) between the outer surface <NUM> of the circular glass bottom <NUM> and the ground at a given position x,y is determined by means of a non-contact profilometer. For the determination of the individual values of the two-dimensional distance h(x,y), the glass bottom <NUM> is divided into an array of square parts <NUM> having an edge length of <NUM>. At the centre of each of these square parts <NUM> the distance between the outer surface <NUM> of the glass bottom <NUM> and the ground is determined at measurement point <NUM> as shown in <FIG> (the individual measurement points <NUM> are evaluated in an order following the arrows shown in <FIG>) and addressed to the corresponding x and y values of the respective square and stored as an individual value of h(x,y). From the thus obtained values for the two-dimensional distance h(x,y) only those values are selected for calculating the slope magnitude and for determining ĥ(x)max and h(x)min that have been obtained for measurement points <NUM> that are located within a circular area <NUM> having a radius of <NUM> × d2/<NUM> (or within a circular area <NUM> having a radius of <NUM> × d2/<NUM> or within a circular area <NUM> having <NUM> × d2/<NUM>) as shown in <FIG>.

From the thus obtained h(x,y)-values the slope magnitude representing the slope of between measurement points for different x and y, preferably between neighboring measurement points, is calculated using an appropriate mathematical software, for example the "Slope Analysis" function of the Mx software.

The h(x,y)max-value corresponds to the highest h(x,y)-value and the h(x,y)min-value corresponds to the lowest h(x,y)-value that have been determined within the circular area <NUM> having a radius of <NUM> × d2/<NUM> (or within the circular area <NUM> having a radius of <NUM> × d2/<NUM> or within the circular area <NUM> having a radius of <NUM> × d2/<NUM>).

<FIG> shows in a side view the localization of plane <NUM> that is used to determine s2max and s2min in the bottom <NUM> of the glass container <NUM>. Plane <NUM> corresponds to the plane that is centrically located in the glass container <NUM> and that comprises the longitudinal axis Ltube of the glass container <NUM> (indicated by the dashed line in <FIG>), i. the axis that goes perpendicular through the centre <NUM> of the bottom <NUM> (see <FIG> shows the localization of s2max and s2min as well as the width of the area within which these values are to be determined in an exemplary bottom cross-section. As can be seen, s2max and s2min are determined within an area that extends over about <NUM> % of the area of the circular glass bottom, wherein the centre of this area is located in the centre <NUM> of the circular glass bottom <NUM>.

<FIG> show the process for the preparation of a glass container <NUM> that displays a glass bottom as define herein. In a first process step I) the glass tube <NUM> having an upper portion <NUM> with an upper end <NUM> and a lower portion <NUM> with a lower end <NUM> is held by means of upper and lower clamping chucks <NUM>,<NUM> in a vertical position. The glass tube <NUM> is heated at a defined position between the lower and the upper portion <NUM>,<NUM> by means of two opposed separation gas burners <NUM> to a temperature above the glass transition temperature while the glass tube <NUM> is rotating around its longitudinal axis Ltube (see <FIG>). In process step II) the lower portion <NUM> of the glass tube <NUM> is pulled downwards by moving downwards the lower clamping chucks <NUM> while the glass tube <NUM> is rotating around its longitudinal axis Ltube (see <FIG>). When moving downwards the lower clamping chucks <NUM> and thus also the lower portion <NUM> of the glass tube <NUM>, a glass thread <NUM> is formed (see also <FIG>). When further moving downwards the lower portion <NUM>, this portion is separated from the upper portion <NUM> by pulling apart the glass thread <NUM>, the part of the mass of the glass thread <NUM> that remains at the lower portion <NUM> of the glass tube <NUM> forming a circular bottom <NUM> (see <FIG>). The process for the preparation of a glass container is characterized in that, while pulling downwards the lower portion <NUM>, the at least one separation gas burner <NUM> does not remain at the same position as it is observed in the process known from the prior art, but is moved downwards in a direction that is substantially parallel to the direction in which the lower clamping chucks <NUM> are moved downwards (indicated by the arrows beneath the separation gas burners <NUM> in <FIG>), the at least one separation gas burner <NUM> thereby following the upper end <NUM> of the lower portion <NUM>.

<FIG> shows the movement of the separation gas burners <NUM> and the lower clamping chucks <NUM> at the time at which the lower clamping chucks <NUM> are moved downwards. In the embodiment of the process shown in <FIG>, the lower clamping chucks <NUM> are moved downwards at a point of time t and the at least one separation gas burner <NUM> is moved downwards at a point of time t' = t + Δt, wherein Δt can be zero (which means that the lower clamping chucks <NUM> and the at least one separation gas burner <NUM> are moved downwards simultaneously) or Δt can be larger than zero. In this case the at least one separation gas burner <NUM> is moved downwards with a time delay in relation to the lower clamping chucks <NUM>. As can also be seen in the embodiment of the process shown in <FIG>, the at least one separation gas burner <NUM> is moved downwards starting from a position Y'<NUM> to a position Y'stop and the lower clamping chucks <NUM> start from a position Y<NUM> and, preferably after the at least one separation gas burner <NUM> has stopped at position Y'stop, to stop at a position Ystop, wherein |Y'stop - Y'<NUM>| < |Ystop - Y<NUM>|. According to this embodiment it is thus preferred that the distance with which the at least one separation gas burner <NUM> is moved downwards is smaller than the distance with which the lower clamping chucks <NUM> are moved downward.

<FIG> shows the experimental setup to characterize wavefront distortions caused by the outer shape of the glass bottom <NUM> of a glass container <NUM> (which in <FIG> is a vial), independent of the imaging system eventually used for the inspection. A collimated laser beam <NUM> of <NUM>/e<NUM> diameter (2W = <NUM>) and wavelength of <NUM> from a laser source <NUM> (e.g. Thorlabs PL201, in order to cover <NUM>% of d<NUM> for vial with d<NUM>=<NUM> it has been extended to 2W = <NUM> with the Beamexpander Thorlabs GBE01-A) is directed towards the glass bottom <NUM> of a vial <NUM> standing on a transparent support <NUM>. Since the inspection is usually carried out with a filled vial <NUM>, the vial <NUM> is filled with water <NUM> up to a height that completely covers the inner surface <NUM> of the glass bottom <NUM>. Practically this can be achieved with a fill height of <NUM>. The effect of the inner surface <NUM> of the glass bottom <NUM> on the optical imaging can be neglected since nvial - nfilling ≈ <NUM> < nvial - nair ≈ <NUM>, thus the inner surface <NUM> of the glass bottom <NUM> has a much smaller effect on the wavefront. However, in this measurement it is intended to completely eliminate the influence of the inner surface <NUM> of the glass bottom <NUM> and for that purpose an index-matching liquid of n = nvial is selected. One crucial factor of the measurement is the inner neck diameter d4 of the vial <NUM>. In order to characterize the wavefront distortion for a laser diameter that is larger diameter than d<NUM>, the top region of the vial <NUM> is removed along a cutting plane <NUM>. Thus, if no further imaging optic (e. another beam expander used in reverse) is used, the measurement aperture <NUM> of the Shack-Hartmann sensor <NUM> determines the diameter of the wavefront measurement. For the experimental set up used herein a Shack-Hartmann sensor <NUM> with a large aperture <NUM> of <NUM> × <NUM> has been used (WFS40-7AR, Thorlabs Inc. Thus, in this setup it would be necessary to shrink the beam size with another beam expander, if vials with d<NUM> larger than <NUM> are investigated.

The Shack-Hartmann sensor <NUM> contains an array micro-lenses <NUM> that images a characteristic dot pattern onto a CCD. For a planar wavefront <NUM>, the dot pattern has the same spacing as the spacing of the micro-lens array. However, if the wavefront is aberrated when passing through the glass bottom to obtain the aberrated wavefront <NUM>, any aberrations locally displace the dot laterally in the direction of the distortion (as shown in <FIG> of the publication "<NPL>). This way, the distortion can be mapped onto the nodes Wi the micro-lens array the Shack-Hartmann-Sensor <NUM> provides.

Claim 1:
A glass container (<NUM>) comprising as container parts
i) a glass tube (<NUM>) with a first end (<NUM>), a further end (<NUM>), an outer diameter d1, an inner diameter d2 and a glass thickness s1, the glass tube (<NUM>) being characterized by a longitudinal axis Ltube that passes through the centre of the first and the further end (<NUM>,<NUM>);
ii) a circular glass bottom (<NUM>), wherein the circular glass bottom (<NUM>) closes the glass tube (<NUM>) at the first end (<NUM>), wherein the circular glass bottom (<NUM>) comprises an inner surface (<NUM>) directed to the inside of the glass container (<NUM>), an outer surface (<NUM>) directed to the outside of the glass container (<NUM>) and a centre (<NUM>);
iii) a curved glass heel (<NUM>) extending from an outer end (<NUM>) of the circular glass bottom (<NUM>) to the first end (<NUM>) of the glass tube (<NUM>);
- wherein the topography of the outer surface (<NUM>) of the circular glass bottom (<NUM>) is defined by a function ĥ(x),
- wherein ĥ(x) is the azimuthal average of the distance between
a) a contact plane (<NUM>) representing the ground on which the glass container (<NUM>) rests with at least a part of the circular glass bottom (<NUM>) being in contact with the ground, and
b) the outer surface (<NUM>) of the circular glass bottom (<NUM>)
at any given position that is located on a circle (<NUM>) having a centre that corresponds to the centre (<NUM>) of the circular glass bottom (<NUM>) and the radius |x|,
- wherein individual values ĥ for ĥ(x) are determined for a plurality of circles (<NUM>) the radius of which increases stepwise by <NUM>, starting with a circle (<NUM>) around the centre (<NUM>) of the circular glass bottom (<NUM>) having a radius of <NUM>, and wherein the individual values ĥ are determined in the range from x = - <NUM> × d2/<NUM> to x = + <NUM> × d2/<NUM>, d2 having a size such that at least <NUM> values ĥ are determined,
- wherein the thus obtained individual values ĥ can be fitted in a least square fit with a curvature function (I) <MAT> c and h<NUM> being free fitting parameters, and
- wherein Δc is the standard deviation error for constant c when fitting the individual values ĥ(x) with curvature function (I) and wherein the relative standard deviation error Δc/c is less than <NUM>.