NO975019L - Apparatus and method for mixing a pharmaceutical composition with another agent and method for oral administration of the pharmaceutical composition - Google Patents

Description

The present invention relates to a device for mixing a pharmaceutical, preferably dry and granular, composition with another, preferably fluid, agent into a preparation, preferably a gel, in accordance with what is stated in the introduction to accompanying claim 1.

The main problem that forms the basis of the present invention relates to the handling, storage and administration of a pharmaceutical preparation to be mixed with another agent, which may have a harmful effect on the composition to be formed into a preparation suitable for administration to a living being, especially an animal .

It is well known in the field of veterinary technology to administer pharmaceutical compositions in the form of paste-like preparations to horses by means of a syringe-like device. The syringe is then introduced into the horse's mouth and the preparation is expelled so that it is dispensed at the root of the tongue. The viscous nature of the preparation and its placement at the back of the mouth make it difficult for the horse to spit the preparation out.

In some cases, such preparations, for example comprising a mixture of a pharmaceutical composition and a consistency-forming agent, will have a short storage stability. The components contained in these preparations must therefore be kept isolated from each other until shortly before use, as they are mixed together to form the desired preparation.

There are a number of solutions to the problem of storing and mixing two components of a preparation, which cannot be stored for a longer period of time after mixing.

The most common previously known solution is a syringe of the type described in US-A-3 340 873, which has a plunger piston slidably arranged in a cylindrical body. The two components to be mixed are contained in two different chambers which are isolated from each other by means of a thin diaphragm. Shortly before the preparation is to be used, the diaphragm is broken or perforated so that a communication is established between the two chambers. The syringe with the mixture is then shaken to form a homogeneous preparation. After this operation, a cover is removed to open a passage and the contents are expelled through a needle by depressing the plunger.

This type of previous technique has in most cases proven to be satisfactory and reliable and is also relatively easy to produce, for example by plastic injection molding, at low costs.

However, the above-mentioned syringe is not suitable for the administration of a gel, mainly due to the presence of the needle. Apart from this, however, it is generally the case that mixing devices having two chambers isolated from each other by a thin rubber or plastic diaphragm cannot be used for certain types of moisture-sensitive pharmaceutical compositions. An example of such a composition are compositions comprising a proton pump inhibitor, such as omeprazole, which degrades during long-term storage in the presence of moisture. The ever-present molecular migration through a rubber or plastic diaphragm will be sufficient to cause degradation of such sensitive compositions during long-term storage.

The conventional two-chamber mixing devices are unsuitable for such compositions.

DK patent 112 893, filed 25 July 1966, describes an injection syringe for injection of a pharmaceutical composition which cannot be stored in solution for a longer period of time without harmful effects. The syringe essentially corresponds to a standard syringe, the main difference being that the opening in the needle adapter is sealed with a diaphragm. The composition is contained in the syringe in dry form. When the syringe is to be used, an injection needle that is the same at both ends is mounted in the needle fitting, with one end perforating the diaphragm. Solvent is sucked into the syringe through the needle. Then the syringe is shaken and the resulting solution is injected through the needle.

A disadvantage of this type of syringe is that the filling operation is rather complex, it necessitates the fitting of an injection needle which is the same at both ends for perforating the diaphragm. Furthermore, after the diaphragm has been broken, the mixing chamber will be open to the surrounding air so that during the shaking operation care must be taken to prevent the mixture from leaking out through the needle. Furthermore, due to the high flow resistance in the syringe due to the narrow passages therein, especially in the needle, it cannot be used for viscous, paste or gel-like preparations. Moreover, this known apparatus is not suitable for oral administration because of the needle. Furthermore, the production costs for the syringe will be relatively high.

An object of the present invention is to avoid the disadvantages associated with the prior art by providing a mixing device in which a pharmaceutical composition can be stored for a longer period of time and to which a desired agent can be easily and quickly added immediately before administration of the preparation. After adding the agent, it should also be possible to shake the device vigorously without leakage. Furthermore, the production costs for the device according to the invention should be relatively low.

This object of the invention is achieved by a device in accordance with the introduction in the accompanying claim 1, which includes the features in the characterizing part of claim 1.

Further independent claims define methods using the device for mixing a pharmaceutical preparation and methods for administering a mixed preparation using the device.

When using for administration of the preparation, a gasket or a seal must first be removed which protects the pre-filled chamber against moisture during storage. The agent is then added to be mixed with the composition contained in the chamber, the fluid agent being separated from the chamber by means of the flexible sealing element. The plunger piston is then displaced in the opposite direction to the expulsion direction causing an expansion of the closed chamber defined by the plunger piston, the sidewall portion and the closure portion, thereby creating a vacuum in the chamber. Initially, the pressure differential across the sealing element will be too low to bend it, but as the plunger piston continues to be displaced, the vacuum in the chamber gradually increases so that the sealing element is deformed and loses its contact with the wall, thereby establishing a communication into the chamber. The agent will then be sucked into the chamber. When the required amount of agent has been drawn into the chamber and the flexible sealing member has been bent back to its resting position, the device is shaken until the preparation is ready for administration. Just before the administration is to be carried out, the closing part of the chamber is removed and the device is introduced, for example, into the mouth of a horse. The contents of the device are now expelled by depressing the plunger.

Description of preferred designs

Preferred embodiments according to the invention will now be described by way of example with reference to the drawings, where:

Fig 1 is an axial section in a first preferred embodiment of the invention,

Fig 2 shows the circled part of Fig 1 on a larger scale,

Fig 3 is a cross-section along the line III-III of Fig 1,

Fig 4 is an axial section in a further embodiment, which is somewhat modified in relation to that in Figs 1-3,

Fig 5 shows the circled part of Fig 4 on a larger scale,

Fig 6 is a section along the line IV-IV in Fig 4,

Fig 7 shows part of a slight modification of the design in Fig 4 on a larger scale,

Fig 8 is an axial section in yet another embodiment of the invention,

Fig 9 is a section along the line IX-IX in Fig 8,

Fig 10 shows the circled part of Fig 8 on a larger scale, and

Fig 11 shows a slight modification of the design in Figs 8-10.

As shown in Fig. 1, the syringe-like device in the first embodiment of the invention comprises a tubular, elongated, cylindrical, hollow body 2, which is open at both ends. The lower end in Fig. 1 is the outlet end 4. A plunger piston 6 is inserted through the open upper end 10. A flange part or a finger grip part 13 runs substantially perpendicular to the longitudinal direction of the hollow body 2 around its upper end. The outlet end 4 is closed with a removable cover 12 having a groove 14 with a diameter corresponding to that of the side wall 8 of the hollow body 2. The groove 14 is designed to have a depth to provide an airtight seal with the lower end 4 to the cylindrical body into the interior of the hollow body 2. The cover 12 has a radially projecting knob 16 to facilitate removal of the cover 12 when the preparation is to be expelled.

As can best be seen in Fig. 2, the plunger piston 16 comprises two parts 18, 20, a carrier device 18 in the form of a flat step, which extends diametrically, perpendicular to the axis of the hollow body 2 and a sealing element 20 in the form of a thin, flexible disk, which in the unloaded state is sized so that it is in sealing contact with the inner wall 8 of the hollow body 2, thereby isolating the spaces on each side of the sealing element 20 from each other. The disc 20 is centrally provided with a plug 22, which has a compressible bulging end part 24, while the step 18 has a central opening 26 with a diameter smaller than that of the bulging part 24. The neck part 28 of the plug 22 is adapted to thickness of the step 18 so that the plug 22 can be snapped into the opening 26 so that the disc 20 will lie close to the step 18.

A rod 30 is arranged in one with the plunger piston 6. Its outer diameter is somewhat smaller than the inner diameter of the hollow body 2 so that the rod 30 is slidably guided therein. The rod 30 is tubular and its ring-shaped end part 32 merges with the step 18. The end surface of said part 32 is flush with the end surface (the lower surface in Fig. 1) of the step 18. At the open end 40 of the rod 30, a radially protruding finger grip 23.

The flexible disk 20 consists of an elastic material and will bend down when it is subjected to a sufficiently large force and return to its original position when said force is removed. When the cover 12 or other seal is placed on the outlet end 4, a closed chamber 38 is defined by the cover 12 or other seal, the flexible disk 20 and the inner wall 8 of the hollow body, the volume of the chamber being variable due to the axially displaceable plunger piston 6. When it is snapped into the hole 26, the unloaded disc 20 rests against the step 18 and the rod 30's annular end part. The circumferential edge part 34 of the disk 20 is prevented from bending upwards by the step 18 and the annular end part 32. On the other hand, the edge part 34 is allowed to bend downwards. If this occurs, the edge part 34 will lose its sealing contact with the inner wall 8 of the hollow body 2 and thereby open a communication at the wall 8 between the upper and lower sides of the flexible disc 20. The disc 20 thus functions as a one-way valve.

It should be pointed out that any method can be used for fixing the elastic disc 20 to the rod 30. A keyhole connection can be used, for example. A keyhole opening is thereby arranged at the bottom of the rod 30 and the plug 22 of the sealing disc 20 is then inserted through the wide opening of the keyhole and then pushed into the narrow slot of the keyhole. In another fixing method, the flexible disk 20 can be provided with a neck part at its center part, which part is then introduced into an opening which is arranged at the lower end of the rod 30. The end of the neck part is then heated to a softening temperature thereby flattening to form a rivet-like joint.

As mentioned above and as can be seen in Figs 1-3, the rod 30 is tubular and has an open bottom which is normally sealed with the flexible disk 20. The interior 36 of the rod 30 and the disk 20 form a filling chamber for the agent to be mixed with the composition which contained in the chamber.

The function of this first embodiment of the device will now be described through an example. A suitable composition for the device is described in WO/SE94/25070.1 the following example constitutes the pharmaceutical composition of spheres of an active substance, such as enteric coated omeprazole pellets mixed with a gel-forming agent such as xanthan gum, guar gum, locust bean gum, tragacanth, modified cellulose derivatives or similar, to which mixture of dry components a fluid agent such as water is later added to form a viscous gel. The use of the device as defined in the present invention shall not be limited to use in connection with an omeprazole preparation.

A suitable dose of a dry mixture of enteric coated omeprazole pellets and a gelling agent is filled into chamber 38. A buffer or pH adjusting agent such as citric acid may optionally be added to prevent premature dissolution of the enteric coated pellets when water is later added to the composition. This operation can be carried out in two ways, either the plunger piston 6 is placed in a suitable position in the hollow body 2 with the cover 12 removed, the filling then taking place through the lower end 4, or the cover 12 is placed on the lower end 4 with the plunger piston 6 is removed, the filling then taking place via the upper opening 10. The amount or volume of the mixture is optional within certain limits, because the volume of the chamber 38 is variable due to the axially displaceable plunger piston 6. When the filling is complete, the cover 12 or other seal attached to the end 4 or the plunger 6 is introduced into the hollow body 2, respectively.

It should be pointed out that the hollow rod 30 advantageously serves as a measuring device for the agent to be added to the chamber 38. It is transparent and preferably provided with graduation lines so that the agent to be added can be accurately measured with the device. Excess agent can be poured off the rod 30 before the rod 30 has been displaced to open a communication into the chamber 38. Thus, due to the incorporated metering device provided by the special construction of the rod 20, a very accurate metering of the agent to be is added without the need for any additional devices other than the syringe itself.

Considering the hygroscopic nature of the gelling agent and a necessary shelf life of several years for the pharmaceutical composition, the contents of the chamber must be protected against ingress of moisture, which would otherwise accumulate in the gelling agent to sooner or later cause degradation of the omeprazole material during long-term storage . After the filling operation, the device is therefore enclosed by a moisture-proof casing, which preferably has a moisture barrier consisting of aluminum, but other materials that fulfill the same purpose are of course also possible. A desiccant, preferably in a small bag, is conveniently placed in the enclosure as a further protection against moisture. As an alternative to the packing discussed above, it could be sufficient to provide an impermeable seal or cover of a similar material over the open end 40 of the rod 30. A desiccant can then be incorporated into the seal or cover to absorb any penetrating vapor. The device can now be stored for several years until use.

When it is to be used, the device is taken out of the moisture-tight packing or the seal over the tubular rod 30 is removed. A suitable amount of water to be added to the mixture in the chamber 38 is then filled in the tubular chamber of the rod 30 up to a desired level (marked by a graduation line or level mark). The plunger piston 6 is then displaced upwards and thereby creates a vacuum in the chamber 38. After a sufficient displacement, the vacuum will become so strong therein that the flexible disc 20 will bend downwards, whereby the circumferential edge 34 of the flexible disc 20 loses its sealing contact with the inner wall 8 so that a communication is established from the chamber 36 into the chamber 38 so that the water in the chamber 36 of the rod 30 will be sucked into the chamber 38. When the water has been transferred there, the disc 20 will bend back to its rest position and the device is then shaken until it has been formed a viscous gel containing the omeprazole pellets. During the shaking operation, the mixture is prevented by the flexible disk 20 from leaking into the chamber 36. The mixture could be stored in the device for a short period of time before administration. Just before administration, cover 12 is removed and the device is placed where the preparation is to be administered. The preparation is then expelled by pressing down on the rod 30.

The rod 30 suitably has such an axial length that when it is pressed all the way down, all the preparation will be expelled from the device. The flexible disc 20 preferably has a smooth surface for complete expulsion of the composition and thereby avoids the risk of any residues, pellets or gel remaining in openings or slits, which could occur with a split disc.

Instead of the plastic cover 12, a seal can be arranged which can be torn off or broken to seal the chamber 38.

Fig 4 shows a slight modification of the design in Figs 1-3.1 instead of being open at the bottom end, the tubular rod 30a has two opposed longitudinal slits 42 which extend from the bottom part of the rod 30a up to about half the height of the rod 30a and thus provide a connection between the inner 36a of the rod 30a and the upper side of the disk 20a. The bottom part includes an opening 26a in the middle, which functions in a similar way to the opening 26 in the embodiment in Fig. 1. The bottom part of the rod 30 is circular and provides a support for the middle part of the flexible disk 20a.

In a further modification of the embodiment in Fig. 4, the sealing element 20'a is integrated with the rod 30'a and consists of an annular flexible ring, see Fig. 7. The advantage of this embodiment is that it only requires a single operation in the manufacture of the rod 30' a and the sealing element 20'a.

In yet a further modification (fig. 8-10) of the above-described designs, the rod 30b is tubular while its lower part 46 has a cross-section in the form of a cross, as is clear from fig. 9. The lower part thus consists of two i longitudinally extending, perpendicular wall parts 48, 50 which extend from the bottom part of the rod 30b up to half the height of the rod 30b. From the tubular portion 44 and proceeding downwards, the cross-shaped portion 46 includes a first portion having a constant section to provide sufficient stiffness and control against the inner wall 8. The subsequent portion 56 tapers downwards toward the bottom portion, which in turn includes an annular rim 60 for supporting the flexible disc 20b and preventing it from being bent upwards. The bottom part also includes an opening 62 into which the bulge 24b of the flexible disc 20b is snapped (cf. Fig. 10).

A modification of the Fig. 8-10 embodiment is shown in Fig. 11. As in Fig. 7, the flexible sealing member 34'b is integral with the rod 30b, which has a radially projecting annular edge 60', which is extended by a thinner flexible annular edge 34'b in sealing contact with the hollow legement 2 inner wall 8.

In the embodiment of Figs 8-11, the water to be added is introduced as before through the open end 40 of the rod 30b, but in contrast to the previously described embodiments, the water will not be contained in a lower tubular part of the rod, but will rise in the cross-shaped part up to a desired level. In this case, the cross-shaped part may be provided with colored lines to indicate the volume levels. In these embodiments, the rod does not have to be transparent, but can have a suitable color.

As will be appreciated, all embodiments operate in a similar manner. A fluid agent, preferably water, is filled in the upper end 40 of the rod 30, and the water then flows through the opening arranged in the rod and then reaches the upper side of the flexible sealing element. The sealing element prevents the water from reaching the chamber 38. The rod will then be displaced backwards, thereby creating a vacuum in the chamber 38. The combined action of the weight of the water and the vacuum will bend the sealing element downwards so that water will be sucked into the chamber 38. When the water has disappeared from above the flexible sealing element into the chamber, said element will bend back to its original resting position and seal off the chamber 38.

The described solutions offer different advantages. If the sealing element is a separate construction detail, it gives a great deal of freedom when it comes to the choice of material. The material in the sealing element can be chosen to have optimal sealing and elastic properties, while the material in the rod can be chosen so that it provides sufficient rigidity and support for the sealing element. If the rod and the sealing element are made in one piece, the choice of material must be a compromise between the necessary rigidity for the rod and the necessary flexibility and elasticity for the sealing element. This latter solution, however, offers advantages in terms of production costs.

It should also be pointed out that in the two versions all the elements can consist of polymeric materials, such as polyethylene, polypropylene, polyester, elastomer, polycarbonate, rubber or silicone, and are produced using conventional and cheap methods, such as injection molding . All the details also have a simple construction and are easy to put together. The devices can therefore be produced at a low price.

In the above-described embodiments according to the invention, the cover 12 is provided with a radially projecting knob 16, which extends around part of the circumference of the cover 12 and forms a gripping part to facilitate the removal of said element. It should be understood that the gripping portion may have any suitable configuration. It can, for example, be oval or it can consist of a protruding flange that extends over the entire circumference of the cover.

The devices are particularly suitable for oral administration to an animal, especially a horse, especially of an aqueous gel containing a formulation of a proton pump inhibitor, for example omeprazole or a similar preparation. However, it will be obvious to one skilled in the art that the use of the device is not limited to this area because it can be used for mixing different types of pharmaceutical compositions with other agents, and for oral, rectal or any other suitable administration to many kinds of living individuals, including humans.

It should also be pointed out that a pharmaceutical composition in the present context does not exclusively mean a drug, as other types of useful agents, e.g. essential foodstuffs, are also intended to be covered by this term.

Claims (32)

1. Device for mixing a pharmaceutical, preferably dry and granular, composition with a, preferably fluid, agent into a preparation, preferably a gel or the like, and later administering the preparation to a living creature, e.g. an animal or a human, where the device comprises a hollow body (2) which has an outlet (4) sealed with a removable closure part (12), a plunger piston (6, 6a, 6'a, 6b, 6'b), which is displaceably placed in said hollow body (2) and in sealing contact with the inner wall of the hollow body (8), an impact device (30, 30a, 30b) connected to the plunger piston (6, 6a, 6'a, 6b, 6'b), for displacing this in said hollow body (2), characterized in that the plunger piston (6, 6a, 6'a, 6b, 6'b), in said hollow body and said removable closing part which delimits a chamber for said composition, comprises a sealing element (20, 20a, 20'a, 20b, 20'b) which has a flexible edge part (34, 34a, 34'a, 34b, 34'b) in sealing contact with the hollow legement (2) inside wall (8), where one side of said edge part faces said chamber (38) and thereby separates the chamber from the opposite side of the flexible edge part, the edge part being supported to be able to be bent in a sufficient direction in only one direction for breaking its sealing contact with the inner wall (8) of the hollow body (2) to establish a communication between the chamber (38) and said opposite side of said edge part, when the plunger piston is displaced in a direction away from the chamber (38). 2. Device according to claim 1, characterized in that the influencing device is a tubular rod (30, 30a, 30b) which is provided with at least one opening at a bottom part thereof. 3. Device according to claim 2, characterized in that the rod (30, 30a, 30b) has a diametrically extending step (18), where openings are defined between the side edges of the step (18) and the inner wall of the tubular rod (30). 4. Device according to claim 3, characterized in that the step (18) has a central opening (26) which is adapted for releasable connection of the flexible sealing element (20) with the rod (30), where the sealing element is circular and extends at least to the outer wall of the tubular rod. 5. Device according to claim 2, characterized in that the tubular rod (30a) has a closed bottom part and axial slits (42) extending from said bottom part. 6. Device according to claim 5, characterized in that the flexible sealing element is a circular disk (20a), which is releasably attached to said bottom part. 7. Device according to claim 6, characterized in that the flexible sealing element is integrated with the tubular rod (30'a) and consists of a flexible ring-shaped ring (34'a) which extends radially from said bottom part to the inner wall of the hollow leg (2) ( 8). 8. Device according to any one of claims 2-7, characterized in that the tubular rod (30, 30a, 30'a) includes a volume measuring device for said agent to be supplied. 9. Device according to claim 8, characterized in that the tubular rod (30, 30a, 30'a) has level graduations for said agent to be supplied. 10. Device according to claim 8 or 9, characterized in that the tubular rod (30, 30a, 30'a) is transparent. 11. Device according to claim 2, characterized in that the rod (30b) includes a tubular first part (44) connected to another part (46) which has a cross-shaped cross-section. 12. Device according to claim 11, characterized in that the second part (46) tapers towards the bottom part of the rod (30b). 13. Device according to claim 11 or 12, characterized in that the rod has a plate-shaped bottom part which has a central opening (62) adapted for releasable connection of the flexible sealing element (20b) with the rod (30b), where the sealing element is circular and extends to the hollow body's (2) inner wall. 14. Device according to claim 11 or 12, characterized in that the flexible sealing element is integrated with the rod (30b) and consists of a flexible ring-shaped ring (34'b) which extends radially from said bottom part to the inner wall (8) of the hollow body (2) ). 15. Device according to any one of claims 11-14, characterized in that the cross-shaped second part (46) includes a volume measuring device for said agent to be supplied. 16. Device according to claim 15, characterized in that the second part (46) has level grading for said agent to be supplied. 17. Device according to claim 16, characterized in that said level gradations are colored lines. 18. Device according to any one of claims 11-17, characterized in that the second part (46) is colored. 19. Device according to any one of claims 2-18, characterized in that the tubular rod (30, 30a, 30b) includes an open end (40) remote from the plunger piston (6), which is closed with a moisture-tight seal. 20. Device according to any one of claims 1-19, characterized in that said closing part is a removable cover (12). 21. Device according to any one of claims 1-19, characterized in that the removable closing part (12) is a closing part that can be broken or torn off. 22. Device according to any preceding claim, characterized in that the chamber (38) is filled in advance with said pharmaceutical composition and that the device is enclosed by a moisture-tight casing comprising at least one moisture barrier. 23. Device according to claim 22, characterized in that said at least one moisture barrier comprises an aluminum layer. 24. Device according to claim 22 or 23, characterized in that said casing contains a desiccant. 25. Device according to any preceding claim, characterized in that said pharmaceutical composition consists of enteric coated pellets comprising proton pump inhibitor, e.g. omeprazole pellets, mixed with a dry gel-forming agent. 26. Method for producing a pharmaceutical preparation by mixing a pharmaceutical, preferably dry and granular, composition with a, preferably fluid, agent shortly before administration thereof to a living creature, characterized by the following steps: a) filling the composition in a chamber (38) of a device comprising a hollow body (2;) and a plunger piston (6;) which is displaceable therein in sealing engagement with an inner wall part of the hollow body (2;), so that a movable end wall is defined in the chamber (38), where the plunger piston (6) comprises a sealing element (20) which has a flexible end part (34) in sealing contact with the inner wall (8) of the hollow body (2), which separates the chamber (38) ) from the opposite side of the edge part, and where the edge part (34) can be bent so that a communication is established between the chamber (38) and the opposite side of the edge part (34), b) closing said chamber with a closing part (12), c) placing a moisture-proof seal on said filled chamber (38), d) storage of the device until the time of use, e) removing the moisture-tight seal of the chamber (38), f) expanding the chamber (38) by displacing the plunger piston (6), which causes the edge part (34) to open, whereby communication is established between the chamber (38) and the opposite side of the edge part so that fluid medium is transferred to the chamber (38), g) if necessary, shaking of said device until the preparation is formed, h) providing an opening to the chamber (38) by removing the closing part (12) when the preparation is to be administered, whereby the preparation can be expelled from the device by displacement of the plunger piston (6) towards said opening. 27. Method according to claim 26, characterized in that the moisture-tight seal in step c) of the chamber (38) is achieved by enclosing the device in a moisture-tight enclosure, which comprises at least one moisture barrier. 28. Method according to claim 27, characterized in that said at least one moisture-tight barrier is an aluminum layer. 29. Method according to any one of claims 26-28, characterized in that the pharmaceutical composition consists of enteric-coated pellets of a proton pump inhibitor, e.g. omeprazole pellets, mixed with a dry gel-forming agent and that said preferably fluid agent is water. 30. Method for oral administration to a living creature of a pharmaceutical preparation, characterized in that it is carried out by mixing a preferably dry and granular composition with a preferably fluid agent using a device according to any one of claims 1-25. 31. Method according to claim 30, characterized in that said living creature is an animal, e.g. a horse. 32. Method according to claim 31, characterized in that the device is introduced into the horse's mouth just in front of the first premolar tooth, the preparation being deposited on the root of the tongue. 1. Device for mixing a pharmaceutical, preferably dry and granular, composition with a, preferably fluid, agent into a preparation, preferably a gel or the like, and later administering the preparation to a living creature, e.g. an animal or a human, where the device comprises a hollow body (2) which has an outlet (4) sealed with a removable closure part (12), a plunger piston (6, 6a, 6'a, 6b, 6'b), which is displaceably placed in said hollow body (2) and in sealing contact with the inner wall of the hollow body (8), an impact device (30, 30a, 30b) connected to the plunger piston (6, 6a, 6'a, 6b, 6'b), for displacing this in said hollow body (2), characterized in that the plunger piston (6, 6a, 6'a, 6b, 6'b), in said hollow body and said removable closing part which delimits a chamber for said composition, comprises a sealing element (20, 20a, 20'a, 20b, 20'b) which has a flexible edge part (34, 34a, 34'a, 34b, 34'b) in sealing contact with the hollow legement (2) inside wall (8), where one side of said edge part faces said chamber (38) and thereby separates the chamber from the opposite side of the flexible edge part, the edge part being supported to be able to be bent in a sufficient direction in only one direction for breaking its sealing contact with the inner wall (8) of the hollow body (2) to establish a communication between the chamber (38) and said opposite side of said edge part, when the plunger piston is displaced in a direction away from the chamber (38). 2. Device according to claim 1, characterized in that the influencing device is a tubular rod (30, 30a, 30b) which is provided with at least one opening at a bottom part thereof. 3. Device according to claim 2, characterized in that the rod (30, 30a, 30b) has a diametrically extending step (18), where openings are defined between the side edges of the step (18) and the inner wall of the tubular rod (30). 4. Device according to claim 3, characterized in that the step (18) has a central opening (26) which is adapted for releasable connection of the flexible sealing element (20) with the rod (30), where the sealing element is circular and extends at least to the outer wall of the tubular rod. 5. Device according to claim 2, characterized in that the tubular rod (30a) has a closed bottom part and axial slits (42) extending from said bottom part. 6. Device according to claim 5, characterized in that the flexible sealing element is a circular disk (20a), which is releasably attached to said bottom part. 7. Device according to claim 6, characterized in that the flexible sealing element is integrated with the tubular rod (30'a) and consists of a flexible ring-shaped ring (34'a) which extends radially from said bottom part to the inner wall of the hollow leg (2) ( 8). 8. Device according to any one of claims 2-7, characterized in that the tubular rod (30, 30a, 30'a) includes a volume measuring device for said agent to be supplied. 9. Device according to claim 8, characterized in that the tubular rod (30, 30a, 30'a) has level graduations for said agent to be supplied. 10. Device according to claim 8 or 9, characterized in that the tubular rod (30, 30a, 30'a) is transparent. 11. Device according to claim 2, characterized in that the rod (30b) includes a tubular first part (44) connected to another part (46) which has a cross-shaped cross-section. 12. Device according to claim 11, characterized in that the second part (46) tapers towards the bottom part of the rod (30b). 13. Device according to claim 11 or 12, characterized in that the rod has a plate-shaped bottom part which has a central opening (62) adapted for releasable connection of the flexible sealing element (20b) with the rod (30b), where the sealing element is circular and extends to the hollow body's (2) inner wall. 14. Device according to claim 11 or 12, characterized in that the flexible sealing element is integrated with the rod (30b) and consists of a flexible ring-shaped ring (34'b) which extends radially from said bottom part to the inner wall (8) of the hollow body (2) ). 15. Device according to any one of claims 11-14, characterized in that the cross-shaped second part (46) includes a volume measuring device for said agent to be supplied. 16. Device according to claim 15, characterized in that the second part (46) has level grading for said agent to be supplied. 17. Device according to claim 16, characterized in that said level gradations are colored lines. 18. Device according to any one of claims 11-17, characterized in that the second part (46) is colored. 19. Device according to any one of claims 2-18, characterized in that the tubular rod (30, 30a, 30b) includes an open end (40) remote from the plunger piston (6), which is closed with a moisture-tight seal. 20. Device according to any one of claims 1-19, characterized in that said closing part is a removable cover (12). 21. Device according to any one of claims 1-19, characterized in that the removable closing part (12) is a closing part that can be broken or torn off. 22. Device according to any preceding claim, characterized in that the chamber (38) is filled in advance with said pharmaceutical composition and that the device is enclosed by a moisture-tight casing comprising at least one moisture barrier. 23. Device according to claim 22, characterized in that said at least one moisture barrier comprises an aluminum layer. 24. Device according to claim 22 or 23, characterized in that said casing contains a desiccant. 25. Device according to any preceding claim, characterized in that said pharmaceutical composition consists of enteric coated pellets comprising proton pump inhibitor, e.g. omeprazole pellets, mixed with a dry gel-forming agent. 26. Method for producing a pharmaceutical preparation by mixing a pharmaceutical, preferably dry and granular, composition with a, preferably fluid, agent shortly before administration thereof to a living creature, characterized by the following steps: a) filling the composition in a chamber (38) of a device comprising a hollow body (2;) and a plunger piston (6;) which is displaceable therein in sealing engagement with an inner wall part of the hollow body (2;), so that a movable end wall is defined in the chamber (38), where the plunger piston (6) comprises a sealing element (20) which has a flexible end part (34) in sealing contact with the inner wall (8) of the hollow body (2), which separates the chamber (38) ) from the opposite side of the edge part, and where the edge part (34) can be bent so that a communication is established between the chamber (38) and the opposite side of the edge part (34), b) closing said chamber with a closing part (12), c) placing a moisture-proof seal on said filled chamber (38), d) storage of the device until the time of use, e) removing the moisture-tight seal of the chamber (38), f) expanding the chamber (38) by displacing the plunger piston (6), which causes the edge part (34) to open, whereby communication is established between the chamber (38) and the opposite side of the edge part so that fluid medium is transferred to the chamber (38), g) if necessary, shaking of said device until the preparation is formed, h) providing an opening to the chamber (38) by removing the closing part (12) when the preparation is to be administered, whereby the preparation can be expelled from the device by displacement of the plunger piston (6) towards said opening. 27. Method according to claim 26, characterized in that the moisture-tight seal in step c) of the chamber (38) is achieved by enclosing the device in a moisture-tight enclosure, which comprises at least one moisture barrier. 28. Method according to claim 27, characterized in that said at least one moisture-tight barrier is an aluminum layer. 29. Method according to any one of claims 26-28, characterized in that the pharmaceutical composition consists of enteric-coated pellets of a proton pump inhibitor, e.g. omeprazole pellets, mixed with a dry gel-forming agent and that said preferably fluid agent is water.