Abstract:
The present invention relates to a test specimen for visualizing mechanical impact in a mass production process, wherein the specimen comprises of a body, at least one impact detection means at least partially covering a carrier structure of the body and adapted to visualize mechanical impact impinging on the body. A protective coating or layer covers the impact detection means entirely.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
       [0001]    The present application is a U.S. National Phase Application pursuant to 35 U.S.C. §371 of International Application No. PCT/EP2012/054558 filed Mar. 15, 2012, which claims priority to European Patent Application No. 11158764.8 filed Mar. 18, 2011. The entire disclosure contents of these applications are herewith incorporated by reference into the present application. 
       FIELD OF THE DISCLOSURE 
       [0002]    The present invention relates to the field of test specimens adapted to analyze mass production processes for manufacturing and packaging, in particular for filling or bottling cartridges or similar containers with a liquid medicament. 
       BACKGROUND 
       [0003]    Particular medicaments have to be distributed and administered in liquid form which imposes strict requirements for their transportation and storage. In particular, the material such medicament containers are made from has to be inert with regard to the medicament. Typically, liquid medicaments, such like insulin or heparin are commonly stored and commercially distributed in glass containers, such like vials, carpules, ampoules, or comparable glass bottles. 
         [0004]    Also, at least some medicaments are to be administered by way of injection. Therefore, storage containers for such medicaments may be readily designed as a cartridge having a cylindrical body or barrel sealed by means of a slidably displaceable piston. By way of the proximally located piston, distally directed pressure can be applied to the inner volume of such cartridges. Consequently, a pre-defined amount of the liquid medicament can be expelled via a distally located outlet section of the cartridge, which is typically sealed by way of a pierceable septum to be penetrated and intersected by a needle assembly, such like an injection needle. 
         [0005]    However, cartridges or containers in general, are filled or bottled as well as packed in large numbers in a mass production process. Most cartridges, carpules, vials, ampoules or bottles intended to receive a liquid medicament are made of glass. However, in mass production processes, such containers might become subject to frequent mechanical impact, which may lead to breakage or damage of such glass containers. However, if a glass container is damaged or even entirely destroyed in a mass production process, glass splinters as well as spilled medicaments may contaminate the environment in the vicinity of the broken container. In addition container closure integrity may be substantially affected by glass breakage. 
         [0006]    It is therefore an object of the present invention to reduce, to minimize and to prevent damaging of glass containers or cartridges in a mass production process. Preferably, the invention aims to analyze and/or to identify possible root causes for cartridge breakage or damaging in mass production processes. Moreover, the invention aims to facilitate and to enhance maintenance as well as to support adjustments on mass production manufacturing lines in general. It is a further aim to illustrate and/or to visualize mechanical impact and other factors affecting on a cartridge and/or on any other object during manufacture and/or assembly in a mass production process. 
       SUMMARY 
       [0007]    The present invention provides a test specimen for visualizing mechanical impact in a mass production and/or packaging process. For this purpose, the specimen comprises a body and at least one impact detection means which is adapted to visualize mechanical impact impinging on the body or on the test specimen during the mass production process. 
         [0008]    In the present context, the term specimen is used for a large variety of objects to be manufactured in industrial mass production processes. Typically, the test specimen mimics the shape and geometry of impact sensitive objects, e.g. syringes, carpules, ampoules or cartridges which may be intended to be filled with a liquid medicament. Depending on the type of specimen, its body may feature any required geometry. In case of a test cartridge, the body is preferably of substantially cylindrical shape. 
         [0009]    When designed as a test cartridge, the test specimen may resemble and mimic any type of cartridge or container adapted to receive, to store and/or to dispense a liquid substance, in particular a liquid medicament. In that sense a cartridge may comprise a bottle, an ampoule, a carpule or a vial. 
         [0010]    Additionally, the mass production process which is to be characterized and analyzed by the test specimen according to the present invention is not restricted to the actual manufacture of the specimen itself. In the present context, the term “mass production process” may also refer to the bottling and/or filling of the specimen with a liquid substance as well as to a packaging and/or transport procedure, in which the manufactured and filled specimen are normally packed and/or transported in a packaging. 
         [0011]    By making use of a test specimen having impact detection means, any mechanical impact above a predefined threshold can be visualized and tracked later on in order to identify potential hazards for the integrity of the specimen and its body during the mass production process. 
         [0012]    Typically, the test specimen at least slightly differs in weight compared to an original specimen, e.g. a cartridge filled with medicament. The weight difference between a test cartridge and a real cartridge is at least 2 g, at least 5 g or even more. By making use of test specimens or test cartridges featuring a different weight compared to original and real cartridges, test cartridges can be mixed with real cartridges in the production process and may be sorted out afterwards by way of a weight-based test-specimen identification. 
         [0013]    Moreover, the test specimen is substantially identical regarding geometry and outer dimensions compared to a real or genuine specimen. The test specimen should also mimic geometric tolerances of original specimens. 
         [0014]    According to a preferred aspect, the body of a test specimen comprises a carrier structure, for example a tubular carrier structure, at least partially covered with the impact detection means. Typically, the carrier structure is made of a rather rigid and robust material being rather insensitive and resistant to mechanical stress, like externally applied forces, pressure or impact. 
         [0015]    According to another preferred embodiment, the impact detection means plastically deforms in response to a mechanical impact. Preferably, the impact detection means covers or forms the outer surface of the carrier structure. The impact detection means may comprise a rather soft and plastically deformable material, which under the effect of externally applied forces, such like pressure or impact shows a respective deformation. Upon leaving the mass production line, such a deformation of the impact detection means can be detected and analyzed for detecting, tracking and allocating the cause of the mechanical deformation. 
         [0016]    Moreover, by making use of a series of test specimens comprising different impact detection means, a wide range of forces and pressures as well as impact-effects can be monitored. Depending on the deformation properties and also depending on the thickness of the impact detection means, the magnitude of mechanical forces, pressure or impact acting on the test specimen can be at least estimated. 
         [0017]    According to a further aspect, the impact detection means comprises an impact- or pressure-sensitive colouring agent. In this embodiment, the impact detection means does not necessarily have to exhibit plastic deformation but may locally change its colour instead. This way, any force, pressure or impact above a certain threshold leaves a visually detectable imprint on the outer surface of the test specimen. 
         [0018]    It is of further benefit, when the impact detection means is at least partially, preferably entirely covered or coated with a protective layer or coating. Preferably, said coating or layer is substantially transparent and transmits the externally applied mechanical forces or impacts. The protective coating or layer predominately serves as a securing means and is adapted to prevent separation and distribution or loosing of mechanically treated surface portions of the impact detection means. Depending on the mechanical properties of the impact detection means, otherwise it may arise, that parts or portions thereof immobilize or get lost when becoming subject to mechanical stress. 
         [0019]    In order to prevent contamination of the mass production line with loosened particles of the impact detection means, the protective coating or layer, typically designed as a laminated foil, serves to keep the production line clean and non-contaminated, even when a test specimen or its impact detection means becomes subject to severe damages or the like. Hence, the test specimen should leave the production line particle free and abrasion free after a force impact. Preferably, no leftovers should stay in the production line after the test specimen left the same. Otherwise, the regular production and product quality could be affected. 
         [0020]    In a further preferred embodiment, the carrier structure comprises an aluminum hollow body. This way, the test specimen is non-transparent and may be visually identified among real specimen, typically made of glass. The aluminum hollow body may be designed as turned body or as a cast member. 
         [0021]    It is of further benefit, when according to another embodiment the impact detection means comprises a layer of wax, which may be adhesively attached to the carrier structure. Wax or comparable material featuring similar mechanical or elastic properties may easily deform under a force- or pressure impact above a pre-defined threshold. Typically, mechanical deformation of wax is non-elastic but plastic. Once a particular surface portion of the impact detection means has been deformed, the respective deformation retains until the test specimen leaves the manufacturing line. 
         [0022]    In an alternative embodiment, the impact detection means comprises a tubular shaped polymeric body. Typically, such a polymeric body is less prone to mechanically-induced deformations compared to a wax layer. However, by way of a polymeric body, mechanical force effects and impacts within a pre-defined impact range can be detected by a plastic deformation of a polymeric material. By making use of different materials featuring different modulus of elasticity or hardness, mechanical impact and force effects that may arise during a mass production process can be analyzed quantitatively within a large range. 
         [0023]    Typically, the tubular shaped polymeric body is frictionally engaged with the carrier structure designed as a metal cylinder. Frictional engagement of polymeric body and carrier structure may for instance be attained by way of one or several O-rings disposed between an outside wall of the carrier structure and an inside facing wall of the polymeric body. Having a frictional engagement of polymeric body and carrier structure, a used test specimen may be refurbished by simply replacing the polymeric body. 
         [0024]    Another type of test specimen may provide an impact- or pressure-sensitive colouring agent as impact detection means. Preferably, the colouring agent comprises dye-doped micro-capsules adapted to release a particular dye in response to a mechanical impact above a pre-defined threshold. Such micro-capsules may provide a shell-like structure and may be filled with some type of dye. Upon mechanical impact, the shell will be destroyed and the dye may be released in order to modify the colour of the respective surface section, the impact was applied to. 
         [0025]    Test specimen supplied with dye-doped micro-capsules may also comprise a rather rigid carrier structure. The surface of the carrier structure may be roughened, e.g. by sandblasting or comparable procedures in order to enhance adhesion of dye-doped micro-capsules. 
         [0026]    In this embodiment it is of particular benefit, when a micro-capsule-based coating of the test specimen&#39;s carrier structure is further covered or coated with a protective layer, like a laminated foil. In this way, a potential contamination of the production line with colour pigments can be effectively prevented. 
         [0027]    Generally, the invention is not limited to a particular type of test specimen but can be universally applied to a large variety of specimens, each of which being designed for a particular application purpose. For instance, the test specimen may be designed as a cartridge, such like a carpule adapted to be filled with a liquid medicament. Also, the test specimen can be designed as medicament delivery device, such like an inhaler or a pen-type injector. By way of an appropriately designed test specimen, even a manufacturing process of a medicament delivery device can be monitored and analyzed later on. 
         [0028]    In another aspect, the invention further relates to a method of visualizing mechanical impact on specimens in a mass production process, in particular in a respective manufacturing line. The method comprises the steps of replacing an original specimen by at least one test specimen as described above. The original specimen is for instance intended to be filled with a liquid medicament or is already filled therewith. The test specimen mimics the outer appearance of an original specimen and features an almost identical geometry. The test specimen is treated in a similar or identical way in the mass production process as original or genuine ones. 
         [0029]    During or after processing of the test specimen in the production line, an impact detection means of the test specimen is monitored, recorded and/or analyzed in order to identify causes and respective locations in the manufacturing line that may harm the integrity or functionality of such specimens. 
         [0030]    In a further preferred embodiment, differently configured test specimen comprising different sensitivity to external mechanical impact are used in a corresponding way as described above in order to further characterize even the magnitude of mechanical impact that may arise in a manufacturing line. 
         [0031]    Preferably, the method is applicable with test cartridges as test specimens, that mimic the shape and geometry or genuine cartridges to be filled with a liquid substance, like a liquid medicament. 
         [0032]    It will be further apparent to those skilled in the pertinent art that various modifications and variations can be made to the present invention without departing from the spirit and scope of the invention. Further, it is to be noted, that any reference signs used in the appended claims are not to be construed as limiting the scope of the present invention. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0033]    In the following, preferred embodiments of the invention will be described in greater detail be making reference to the drawings, in which: 
           [0034]      FIG. 1  schematically illustrates a test specimen in form of a test cartridge comprising an outer wax layer for visualizing and illustrating mechanical impact that may arise in a mass production process, 
           [0035]      FIG. 2  schematically illustrates a test cartridge comprising an outer polyacrylic sleeve, 
           [0036]      FIG. 3  is illustrative of a test cartridge comprising dye-doped micro-capsules for visually indicating mechanical impact, and 
           [0037]      FIG. 4  finally shows the cartridge according to  FIG. 1  in cross section along A-A. 
       
    
    
     DETAILED DESCRIPTION 
       [0038]    In  FIGS. 1 to 3 , three different embodiments of test cartridges  10 ,  20 ,  30  are schematically illustrated. In all these embodiments, the test cartridges  10 ,  20 ,  30  are illustrated with a piston or rubber stopper  12  slidably disposed in a cylindrical barrel or body  18 ,  22 ,  32 . The piston  12  is only illustrative for an original cartridge, which at its distal and lower end section typically comprises a socket portion provided with a beaded cap  14  that serves to seal the distal end of the cartridge  10 ,  20 ,  30  by way of a pierceable septum  16 . However, the test cartridges  10 ,  20 ,  30  are typically not provided with a displaceable piston  12  and/or with a distal seal  16 , because the test specimens are not intended for use in e.g. a drug delivery device. 
         [0039]    The body  18 ,  22 ,  32  of the test cartridges  10 ,  20 ,  30  typically comprises a rigid and solid carrier structure for an impact detection means  15  adapted to at least partially or even entirely cover or enclose the carrier structure. In the embodiment as illustrated in  FIGS. 1 and 4 , the impact detection means comprises a layer of wax  15  entirely covering the tubular carrier structure  18 , which in this case is made of a hollow aluminum cylinder. 
         [0040]    The wax layer  15  is plastically deformable in such a way, that any mechanical impact above a pre-defined threshold and impinging the cartridge  10  leaves some kind of deformation in the wax layer  15 , which can be visually and/or haptically analyzed later on. The wax layer  15  is further covered or sealed with a laminated foil  17  which is intended to keep the environment of the test cartridge free of leftovers or other particles that may be loosened from the wax coating  15  in the event of a particular force- or pressure-effect. 
         [0041]    Depending on the original thickness  15  and the hardness of the wax layer  15 , even the magnitude of applied forces can be estimated from e.g. the depth and shape of impact-based deformations in or on the wax layer  15 . 
         [0042]    The embodiment according to  FIG. 2  comprises a polyacrylic sleeve  26  frictionally engaged with the carrier structure  22  by way of an O-ring  24  arranged between an outer surface of the carrier structure  22  and an inside facing side wall of the polyacrylic sleeve  26 . By way of the polyacrylic sleeve  26 , only impacts above a pre-defined threshold can be monitored. Further, depending on the hardness of the impact detection sleeve  26 , occurrence of critical mechanical impact can be detected. 
         [0043]    Typically, the polyacrylic sleeve  26  is subject to cracking but does not disintegrate or split into several parts. Additionally, also the polyacrylic sleeve  26  can be provided with a protecting or laminated foil that intends to keep the contour of the sleeve  26  intact even in case of a severe damage. 
         [0044]    The further embodiment as illustrated in  FIG. 3  comprises a tubular carrier structure  32 . By roughening the carrier  32 , e.g. by way of sandblasting or the like, dye-doped micro-capsules can be adhered thereto. 
         [0045]    By way of a layer of micro-capsules, occurrences of critical mechanical impact can be illustrated by way of a respective colouring of the area of impact. The micro-capsules are designed such, that their surrounding shell is subject to breakage when an impact above a pre-defined level impinges the cartridge  30 . Also here it is generally conceivable, to make use of differently coloured micro-capsules featuring different resistance against mechanical impact. This way, even magnitude of mechanical impact could even be colour encoded. 
         [0046]    Hence, impacts of different magnitude or different impact forces above and below certain thresholds can in general distinguished unequivocally. 
         [0047]    Even though the illustrated embodiments exclusively refer to a cartridge, it is to be mentioned here, that the invention as defined in the appended claims is by no way limited to such cartridges in general. In particular, the features described in connection with the shown cartridges can be universally applied also to other devices, such like medicament delivery devices and/or associated packaging in general.