DEVICE FOR THE ADMINISTRATION OF DRUGS

Abstract: The device comprises a container (30) containing a drug and closed by a piston (31), and a housing (10) intended to be fitted to the container so as to cause a needle (20), which is located in a tubular jacket (13) within the housing (10), to pierce a partition in the piston (31). The interior of the container (30) is thus put into communication with the exterior (30) allowing the supply of the drug due to the penetration of the piston (31) into the container (30) following the penetration of the container (30) into the housing (12). The piston (31) and the inner jacket (13) have complementary mushroom-shaped formations in correspondence with the tip of the needle (20) for coupling with each other.

Description: DEVICE FOR THE ADMINISTRATION OF DRUGS The present invention relates generally to devices for the administration of drugs and relates in particular to an improvement which can be made in the solutions described inthepriorIta__L_n ut Q ity model applications 15156- B/89 and TO91UO00078. The invention, having the characteristics claimed specifically in the claims which follow, will now be described, purely by way of non-limiting example, with reference to the appended drawings (corresponding substantially to the Figures 1-4 appended to the specification ofItallsn 15156-B/89) in which: Figures 1 and 2 are axial sections of the two elements (housing and container) which together define a device for the administration of drugs according to the invention, Figure 2 illustrates, in greater detail, the salient element of the invention, that is the structure of the unit for coupling the said housing and 'container, and Figure 4 shows these elements coupled in their position of use. The housing 10, usually made from a plastics material suitable for medical or pharmaceutical uses, has a generally tubular structure which can be seen to comprise an outer jacket 12 and an inner jacket 13. These jackets 12, 13 together define an annular chamber 14 closed at one end by a so-called end wall 11 provided with an attachment formation 38 for the connection, for example, of a hypodermic needle, not illustrated. Within the inner jacket 13, in a central axial position relative to the housing 10, is a needle 20 which, in the embodiment illustrated, extends through practically the entire length of the housing 10 and terminates at its end opposite the end wall 11 ("open" end of the housing 10) in a sharp tip 21. The length of the needle 20 is selected so that the sharp end 21 does not project from the housing 10 and is thus substantially aligned with (or slightly inset from) the open end of the housing 10 where the latter has an external flange 16 which can serve as a hand grip for use of the device. In correspondence with the end wall 11, the needle 20 is supported by a frusto-conical or annular diaphragm or partition which defines a central outlet aperture towards the hypodermic needle. At the opposite .end of the housing lϋ, the needle 20 is supported by a further partition 100 which closes the inner jacket 13 in correspondence with the open end of the housing 10 and is provided v/ith an attachment formation 102. Both the partition 100 and the formation 102 are preferably made from the same material as that forming the- housing 10 overall. The attachment formation 102 is generally mushroom-shaped, with a generally T-shape in transverse section. Whenever, however, it is wished to make use of the solution described in the prior application T091UO00078, the needle may instead be made so as not to extend as far as the end wall 11. In this case (not illustrated here) the needle 20 stops in correspondence with a partition which defines a terminal chamber within the inner jacket 13 intended to contain one of the components (usually a powder) of a two-component drug. The other element of the device, that is the container 30, is defined by a generally cylindrical cup-shaped body of plastics material suitable for pharmaceutical use. This cup-shaped body is closed at its open end by a body 31 intended to act both as a stopper and as a piston which can slide in a substantially sealed manner within the container 30. This latter is intended to receive the drug to be supplied or (in the case of the solution described inItaliεn p______ticn TO91UO00078) the liquid component of the two-component drug to be supplied. When the container is closed, the piston 31 is located close to the open end of the container itself. The piston 31 has an axial through-hole 3,3 -closed by a diaphragm 34 intended to be pierced by the sharpend2L of the needle 20. In general, the piston 31 is of soft material such as rubber and is held in a fixed position until the moment of use by known means, for example a small disc (not illustrated) which acts as a seal and as a stop. The salient characteristic of the solution of the invention is the fact that the piston 31 (immediately above the diaphragm 34, in the non-limiting embodiment illustrated here) has a recess 104 of complementary shape to that of the formation 102 provided in the housing 10. In the case of the recess 104 in the example illustrated here, therefore, this is a negative-mushroom shape having a lower, generally-cylindrical chamber and an upper, narrower neck portion which opens to the exterior of the container 30. A cup-shaped cover 36 protects the open end of the container 30 until the device is used. Usually the latter is packaged in the form of a kit whose two component parts are the housing 10 and the container 30. During use, the cup-shaped cover 36 is removed, together with any locking and sealing means associated therewith (not illustrated) which retain the piston 31 at the open end of the container 30. At this point, the container 30 is engaged with the open end of the housing 10 in the condition illustrated schematically in Figure 4, that is, with the peripheral wall of the container 30 penetrating the annular chamber 14 defined between the jackets 12 and 13 of the housing 10. This result may be achieved by fitting the piston 31 onto the end portion of the inner jacket 13 and then pressing to cause the formation 102 to enter the recess 104 to form a coupling between the piston 31 and the central part of the housing 10. This result is generally achieved by the penetration and snap engagement of the formation 102 (male formation) in the recess 104 (female formation) which is allowed by the generally yielding nature of the soft material of which the piston 31 is made: this means that the lip which defines the narrow mouth of the recess 104 yields elastically as it is penetrated by the formation 102. A coupled condition is thus achieved by snap engagement with precise complementary-form coupling as shown schematically in Figure 4. As a result of the movement which causes this coupling, the needle 20 and more particularly the pointed end 21 thereof pierces the diaphragm 34 so as to bring the chamber within the container 30 into contact with the interior of the needle 20. At this point, a hypodermic needle may be fitted on to the spigot 38 and, when the flanges 16 and the housing 10 have been grasped by two fingers, the pressure of the thumb on the end wall of the container 30 enables this to be pushed into the annular chamber 14 in the housing 10 v/ith the consequent forcing of the piston 31 back into the container 30. The result of this is that the liquid in the container 30 is expelled through the needle and hence through the hypodermic needle fitted on the spigot 38. In the solution of application TO91UO00078, the liquid component of the drug flows from the container 30 into the end chamber containing the powdered component of the drug so as to cause the components to mix and is then expelled to the exterior of the device. The firm attachment of the piston 31 to the central part of the housing 10 which is thus achieved in any case enables the container 30 to be retracted when this is necessary, for example during an injection. In addition, the generally soft character of the material constituting the stopper 31 also achieves good fluid-tight sealing of the connection between the container 30 and the needle 20. The same structure may also be used for the supply of infusions as indicated in Italian application 15156-B/89.

Claims: CLAIMS 1. A device for the administration of drugs comprising a first element (10) and a second element (30) intended to be coupled together in use, in which: the second element (30) is a container for fluid which is closed by a piston (31) which can be made pervious (34) to fluids and which is movable within the container (30) itself in order to cause the fluid to be expelled from -the container (30) , and the first element (10) includes withdrawal means (20,21) which can be coupled to the piston (31) in order to make it pervious (34) and to cause its movement into the container (30), characterised in that the withdrawal means (20,21) and the piston (31) have complementary male (102) and female (104) attachment formations which can form a strong form coupling v/hen the first element (10) and the second element (30) are coupled together in use. 2. A device according to Claim 1, characterised in that the male formation (102) and the female formation (104) are associated with the withdrawal means (20,21) and with the piston (31) respectively. 3. A device according to Claim 1 or Claim 2, characterised in that the male formation (102) is generally rigid while the female formation (104) is generally deformable. 4. A device according to any one of the preceding claims, characterised in that the complementary formations (102,104) have a generally mushroom-shape and/or a T-section structure. 6. A device according to any one of the preceding claims, characterised in that the withdrawal means comprise a needle (20) with a tip (21) ; the tip (21) being surrounded by the respective complementary formation (102) and being located in a generally retracted position in the region of the first element (10) in order to avoid any contact of the tip (21) with the user. 7. A device according to Claim l or Claim 6, characterised in that the withdrawal means (20,21) comprise a needle (20) with a tip (21) and in that the piston (31) has a thin portion (34) intended to be pierced by the tip in order to render the piston (31) pervious. 8. A device according to any one of the preceding claims, characterised in that the first element (10) and the second element (30) have generally cylindrical structures and in that the complementary formations (102,104) are located generally axially of the said elements (10,20) . - ' 9. A device for the administration of drugs, substantially as described and illustrated and for the purposes specified.

Inventors: ROLLANDI GIAN ANDREA, TOMELLINI GIORGIO, ROLLANDI, GIAN, ANDREA, TOMELLINI, GIORGIO
Applicants: TECNOMEDICA RICERCHE SRL, TECNOMEDICA RICERCHE S.R.L.
Application year: 1992
Main classification: A61M5
IPC codes: A61M5