MXPA06004323A - Wet/dry automatic injector assembly - Google Patents

Abstract

An automatic medicament injector having a compartment for a dry medicament component and a compartment for a wet medicament component. The two compartments are separated by a seal structure that has a plug that is moved from a sealing position into a mixing position when the device is activated. The seal structure includes a wiper that scrapes the interior walls in the dry component compartment to prevent the dry component from accumulating at the seal/glass interface. A tapered insert"funnels"the mixed medicament components to an attached needle assembly, but can be removed when the device is filled. A filter is provided between the medicament compartments and the needle assembly. A chamber between the filter and the needle assembly allows for better flow through the filter. An actuation assembly drives the plug into the mixing position and forces the mixed medicament through the needle and into the user.

Description

WET / DRY AUTOMATIC INJECTOR ASSEMBLY REFERENCE TO RELATED REQUESTS This application claims the priority of the Patent Application of E.U.A. No. 10 / 690,987, filed October 23, 2003, which relates to the Patent Applications of E.U.A. Nos. 09 / 897,422, filed on July 3, 2001, and 09 / 972,202, filed on October 9, 2001. Those two applications claim priority to the Provisional Applications of E.U.A. Nos. 60 / 238,458, 60 / 238,448 and 60 / 238,447, all filed on October 10, 2000. The contents of all of those applications are hereby incorporated by reference herein in their entirety. BACKGROUND OF THE INVENTION 2. Field of the Invention The present invention relates to drug delivery devices. More particularly, the present invention relates to automatic injector assemblies capable of mixing two components of a medically and then delivering the mixed medicament to an injection site. 3. Description of the Related Bouquet An automatic injector is a device that allows intramuscular administration (IM) or subcutaneous dose of medication. Generally, the medication is stored as a liquid formulation that is then injected intramuscularly. An advantage of automatic injectors is that they contain a metered dosage of a medically liquid in a sealed sterile cartridge. As such, automatic injectors allow quick and easy IM injection of a liquid medication in emergency situations without the need to measure dosages. Another advantage of automatic injectors is that the administration of the medicament is achieved without the user initially seeing the hypodermic needle through which the medicament is delivered, and without requiring the user to manually force the needle towards the patient. This is particularly advantageous when the medication is self-administered. There are disadvantages associated with the long term storage of medication in a liquid formulation. For example, some medications are not stable in solution and thus have a shorter shelf life than their solid counterparts. To address this problem, automatic injectors have been developed that store the drug in solid form and mix the solid medication with a liquid solution immediately before the injection. These injectors, described for example in the Reissue Patent of E.U.A. No. 35,986, entitled "Multiple-Chamber Automatic Injector", (the disclosure of which is incorporated herein by reference specifically), however, requires the user of the injector to manually break a seal member between the solid and liquid and then manually shake the injector body to expel the solution of the solid component before injection. This increases the time needed to administer a dose of the medication. However, fast delivery of the medication is needed in many emergency medical situations (eg, nerve gas poisoning and chemical agent). Other wet / dry injection devices have been very expensive to manufacture or provide unsatisfactory mixing of the components before injection. Therefore, there is a need for an effective cash injector that stores medication in solid form that does not require manual pre-mixing by the user. COMPENDIUM OF THE INVENTION One aspect of the invention relates to an automatic injection device that contains a pre-filled load of medication to automatically self-administer the medication during actuation thereof. The automatic injection device comprises a housing and a medicament chamber disposed in the housing. The drug chamber includes a first compartment containing a portion of dried medicament and a second compartment containing a portion of medicament. wet that is going to mix with the dry medication portion. A seal structure is provided between the first compartment and the second compartment. The seal structure is initially in a seal condition that keeps the first compartment separate from the second compartment. The seal structure includes at least one flow path and an annular cleaning portion disposed at the front end of the seal structure and positioned to movably couple the internal walls of the first compartment as the seal structure moves through the first compartment. The cleanser portion is configured to direct dried medicament particles coupled with the inner walls of the medicament chamber radially inward as the seal structure moves through the first compartment. The seal structure becomes a mixing condition as a result of activation of the device. The automatic injection device also includes a needle assembly and an activation assembly. The needle assembly dispenses the mixed medication portions from the medication chamber. The activation set is carried by the housing and includes a stored energy source. Activation of the activation set releases stored energy from the stored energy source, causing the seal structure to be converted from the seal condition to the mixing condition, and thereby causing or allowing the medication portions to mix, and force through the needle assembly. Another aspect of the invention relates to an automatic injection device that contains a pre-filled load of medicament for automatically self-monitoring the medicament during actuation thereof. The automatic injection device comprises a housing and a medicament chamber disposed in the housing. The drug chamber includes a first compartment that contains a first portion of medically, and a second compartment that contains a second portion of medication that is to be mixed with the first portion of the medication. The device also includes a seal structure between the first compartment and the second compartment. The seal structure is initially a seal condition that keeps the first compartment separate from the second compartment, and is converted to a mixing condition as a result of activation of the device. A hole set dispenses the medication charge from the medication chamber. The needle assembly has a backward opening with a diameter that is smaller than a diameter of the medication chamber. An insert is mounted at a forward end of the medicament chamber adjacent the needle assembly. The insert defines a tapered flow path that tapers radially inward as it extends axially forward. The activation set is carried by the housing and includes a stored energy source. The activation of the activation set releases the stored energy from the stored energy source, causing the seal structure to convert from the seal condition to the mixing condition, and thus causing or allowing the first and second portions of the medication they are mixed, directed by the insertion radially inward towards the backward opening of the hole assembly, and forced through the needle assembly. Yet another aspect of the invention relates to an automatic injection device containing a load pre-filled medication to self-administer the medication automatically during its activation. The automatic injection device comprises a housing and a medicament chamber disposed in the housing. The medicament chamber includes a first compartment containing a first portion of medicament, and a second compartment containing a second portion of medicament to be mixed with the first portion of medicament. The device also includes a seal structure between the first compartment and the second compartment. The seal structure is initially in a seal condition which keeps the first compartment separate from the second compartment, and becomes a mixing condition as a result of the activation of the device. A needle assembly delivers the medication load from the medication chamber. A filter is placed between the medication chamber and the needle hole assembly. The needle assembly comprises a needle and a needle holder for mounting the needle to the medication chamber. The needle holder defines a needle assembly chamber having a backward opening covered by the filter. The needle assembly chamber has an internal surface that is taper radially inward as it extends axially forward toward a rearward end of the needle. The device also has an activation set carried by the housing that includes a stored energy source. The activation of the activation set releases the stored energy from the stored energy source, causing the seal structure to convert from the seal condition to the mixing condition, and thereby causing or allowing the first and second drug compounds to be mixed or forced through the needle assembly. A further aspect of the invention relates to a method for filling an automatic injection device. The method comprises filling a front compartment of a chamber within the automatic injection device with a dry medicament compound from a front end of the chamber. The method also comprises filling a rear compartment of the chamber with a wet medicament portion from a rear end of the chamber. The rear compartment is separated from the front compartment by a seal structure. Finally, the method comprises sealing the rear compartment of the chamber, placing a tapered insert on the front end of the chamber, and attaching a needle assembly to the front end of the chamber. The tapered insert has a tapered flow path that tapers so that the diameter increases as it extends These and other aspects and advantages of the invention will be described below BRIEF DESCRIPTION OF THE DRAWINGS The invention will be described in conjunction with the following drawing figures, in which like reference numerals designate like elements, and in which: Figure 1 is a longitudinal cross-sectional view of a wet / dry automatic injector assembly in accordance with one embodiment of the present invention; Figures 2A-2B illustrate longitudinal cross-sectional views of needle support assemblies in accordance with certain embodiments of the present invention; Figures 3A-3D illustrate cross-sectional side views of various cartridge or camera configurations and corresponding needle assembly options in accordance with certain embodiments of the present invention; Figure 4 is an enlarged partial cross-sectional side view of a needle / cartridge assembly coupling in accordance with another embodiment; Figures 5A-5D illustrate cross-sectional side views of various embodiments of a seal structure in accordance with the present invention; Figure 6A. is a longitudinal cross-sectional side view of a seal structure in accordance with another embodiment of the present invention, wherein the seal plug is in a closed seal position blocking the flow of the liquid solution of the invention; Figure 6B is a longitudinal cross-sectional side view of the seal structure similar to Figure 6A, but showing the movable seal plug in an open deflection position allowing flow of the liquid injection solution; Figure 6C is a side cross-sectional view of the seal structure of the present invention taken through the line 6C-6C in Figure 6A; Figure 6D is a side cross-sectional view of the seal structure of the present invention, taken through line 6D-6D in Figure 6B; Figure 7 is a longitudinal cross-sectional view of a wet / dry automatic cartridge or cartridge configuration according to another embodiment of the present invention; Figures 8A and 8B are longitudinal cross-sectional views of two additional embodiments of the seal structures in accordance with the present invention; Figure 9 is a longitudinal cross-sectional view of a camera and needle assembly in accordance with a further embodiment of the invention; Figure 10 is a perspective view of an external seal member in the chamber and needle assembly of Figure 9; Figure 11 is a front elevation view of the outer seal member of Figure 10; Figure 12 is a longitudinal sectional view of the external seal member of Figure 10, taken through line 12-12 of Figure 11; Figure 13 is a perspective view of a tapered insert in the chamber and needle assembly of Figure 9; Figure 14 is a front elevational view of the tapered insert of Figure 13; Figure 15 is a longitudinal sectional view of the tapered insert in the camera and needle assembly of Figure 13, taken through Line 15-15 of Figure 14; Figure 16 is a longitudinal sectional view of a portion of the needle assembly of Figure 9, illustrating a chamber behind the needle assembly filter; and Figures 17A-17F are sectional and partially sectional views of a chamber illustrating a process for filling it with dry and liquid medicament components. DETAILED DESCRIPTION In the following description, the present invention is described in relation to a button-type auto injector, whereby the user separates an end cap assembly and presses a button to trigger the injection process. The present invention, however, is not limited to push-button type automatic injectors.; rather, it is contemplated that the present invention can be incorporated into a nose activated auto injector, as described for example in the U.S. Patent. No. 5,354,286, the disclosure of which is incorporated herein by reference for said teaching. Figure 1 is a longitudinal cross-sectional view of an automatic injector assembly 10 in accordance with an embodiment of the present invention. The automatic injector assembly 10 includes a generally hollow tubular plastic housing 110. In general, the housing 110 includes an injection end 111 and an activation end 112, as shown in Figure 1. In the embodiment shown, a actuator assembly 120 is inserted towards the rearward end of the housing 110. The actuator assembly 120 is received within the housing 110 until the flange 115 of the sleeve member 144 is captured within an annular groove 117 in the inner surface of the housing 110. The removable safety cap 130 is releasably secured to the actuator assembly 120. The actuator assembly 120 may be of any conventional type as known in the art, such as that described in the US Patent. , commonly assigned No. 5,391,151, hereby incorporated by reference. The present invention employs a rear end activation device, similar to that in the U.S. Patent. No. 5,391,151 mentioned above, and therefore is only briefly described herein. Actuator assembly 120 includes an activation button sleeve 132 having internal activation surfaces 134. The activation assembly further includes a plastic ring 122 with a rearwardly divided portion that forms the spring fingers 136 as known in the art. The safety cap 130 has a pin portion 138 extending between the spring fingers 136 so as to keep them dispersed when the injector is in a storage condition. The spring fingers 136 terminate in semi-conical configurations including inclined surfaces 139 facing rearwards and flat surfaces 142 forwardly oriented. The collet 122 is surrounded by a cylindrical sleeve 144 having flange 146 extending inwardly at the rearward end thereof. The collar 122 has an annular flange 148 forward. A spiral spring 250 surrounds the collar 122 and is compressed between the flange 148 and the flange 146. The flat collar surfaces 142 are retained in engagement with the backward facing surfaces of the flange 146, and thus are prevented from being move out of the flange surfaces by the pin 138 when the injector is stored. To activate the injector, the safety pin 130 is manually pulled out of the rear end of the injector, thereby removing the pin 138 from between the fingers 136. The activation button 132 can be pushed inward, and as a result of the surfaces activating the same, 134 engages the inclined surfaces 139 of the spring fingers 136. This forces the spring fingers 136 inward toward each other and away from the retaining surfaces of the flange 146. The compressed spring 250 is then free to release the energy stored therein to move the collar 122 forward under the force of the spring to affect an injection operation as will be described later in greater detail. The driven assembly 12Q may be of any known type in the autosampler employing stored energy iibera.bie, For example, instead of employing a spring, it may employ a compressed gas charge. Positioned within the interior of the housing 110 is a vial or chamber 150, preferably made of glass, to contain either a liquid injection solution or a dry medicament, or other types of medicament portions, as appropriate, the chamber 150 it is preferably a hollow cylinder, with a uniform cylindrical internal surface. The liquid injection solution is placed within a wet portion or compartment 151 of the chamber 150. The dried medicament is placed within a dry portion 152 or compartment of the chamber 150. It is contemplated that the dried medicament may be powdered, lyophilized , freeze drying, or any other solid formulation known in the art, A seal structure 160 couples the inner side walls of the chamber 150 to seal the dried portion 152 of the wet portion 151 and to prevent infusion of the solution liquid injection towards the dry portion 152 before the activation of the injector assembly. In addition, a needle assembly 140 is mounted to the front end of the vial or chamber 150 to inject the medicament during activation of the injector assembly. In this embodiment, the front end portion of the chamber 150 has an annular groove 153 formed therein for securing the needle assembly 140. The needle assembly 140 includes a funnel-shaped needle holder 143. The wide end of the needle holder 143 has an annular flange 145, which snaps into the groove 153 to form a seal with the Chamber 150. The needle holder 143 can be made of a resilient plastic material, or metal with a rubber seal that sits within the groove 153. The forward narrow end 147 (see Figure 2A) of the needle holder 143 sealingly receives the trailing end of the hollow needle 141. The needle holder 143 forms a sealed fluid channel from the chamber 150 to the needle 141. A rubber needle cover 202 surrounds the needle 141 and receives the narrow end 147 of the needle holder 143. A filter 190 is sealingly retained through the full broad end mouth of the needle holder 143 by an annular seal washer 156. Alternatively, the filter 190 could be ultrasonically welded or otherwise secured to the needle holder 143. Figures 2B, 3A and 4 illustrate another embodiment of a needle and chamber assembly 140. The chamber 150 in this embodiment is known in the art as a dental cartridge. The dental cartridge has a cylindrical posterior portion and a narrow front neck portion defining an external annular groove 153. The front end of the dental cartridge defines an annular flange portion 154. In this embodiment, the needle holder 143 has an annular backward flange 155 that receives an annular seal member 156 that surrounds both sides of the flange 155. The seal member 156 serves to seal a filter 190 over the broad end of the support 143 of funnel-shaped needle, The surface behind the seal member 156 is sealablely secured against the front surface of the chamber flange 154 by a metal retainer clamp 157, as best seen in Figure 4. As shown in FIG. shown in Figure 1, the front end 1221 of the collar 122 extends toward the rear end of the chamber 150 and is adapted to be connected with a plunger 17Q rearwardly sealing the wet container 151. The plunger 170 is adapted to sealingly engage the side wall of the wet container 150 to prevent leakage of the contents (eg, liquid injection solution) from the wet container 15. The plunger 170 is preferably formed of a material having low friction properties so that collar 122 and plunger 170 can be easily slid into wet container 150 when operated. Alternatively, the plunger 170 can be lubricated with silicone. ? other suitable non-reactive lubricant. The movement of the collar 122 and the plunger 170 pressurizes the liquid placed inside the wet container 151. An appropriate medicament is placed inside a dry container 152. The embodiment of Figures 1 and 2A is advantageous in that it has an open mouth configuration wherein the needle end of the vial or chamber does not taper or taper significantly. Said open mouth configuration allows direct access to the dry portion 152 of the chamber 150 for easy loading. further, the open goose configuration helps prevent cross-contamination between the wet portion 151 and the dry portion 152 in which the dry portion 152 does not have to be filled through the liquid portion 151 of the chamber 150. The needle assembly 140 it can mount to the vial or chamber 150 in a pressure configuration (Figure 3B), an internal mounting configuration (Figure 3C), or an external needle assembly configuration (Figure 3D). As mentioned above, the seal structure 160 is adapted to couple the interior side walls of the chamber 150 to prevent the passage of contents (eg, liquid injection solution) from the wet portion 151 toward the dry portion 152. before the activation of the automatic injection assembly. Generally, the seal structure 160 may include an external seal member 180, a movable seal plug 166, a bypass zone 165, at least one flow path 167, and preferably also includes a filter or membrane 164. Referenced to Figure 5A.-D, preferably seal structure 160 can be formed as a six-piece configuration (Figure 5A), five pieces (Figure 5B), four pieces (Figure 5C), or three pieces (Figure 5D) . More particularly, with reference to Figure 5A, the outer seal structure 18Q of the six-piece configuration may comprise a rigid two-piece annular body 181, wherein the members 181a, 181b thereof are formed in the rigid body of two. parts using, eg, ring welding connections or other bonding techniques in the field. The outer seal structure 180 may further include multiple external seal members 182, eg, two O-rings, to provide an annular seal coupling with the inner wall of the vial or compartment 15Q. The seal structure 180 further includes an internal plug member 166 and a dispersion filter or membrane 164 as will be discussed in more detail below. In another embodiment, as shown in Figures 5B, instead of several O-rings, the outer seal structure 180 may include a single external seal member 182, eg, a unitary package, to provide a seal coupling. annular with the inner wall of the vial or compartment 150. The outer seal member 182 can optionally be secured to the two-piece rigid body 181 using any bonding techniques known in the art. In addition, the rigid body members 181a, 181b can be configured to securely secure the outer seal members 182 within grooved recesses 183. Alternatively, the seal members 182 can be secured to the rigid body members 181a, 181b by an interference fit. As with the first embodiment, a filter or membrane 164 is held in place at the proximal end of the flow path 167 between the member 181a and the member 181b of the two-piece rigid body, in another embodiment, as shown in FIG. the Figures 5C, the outer seal structure 180 comprises a unitary internal rigid member 181 and an external seal member 182. Again, the inner rigid member 181 and the outer seal member 182 can optionally be secured together using any known linkage techniques in the art. In addition, the inner rigid member 181 and the outer seal member 182 can be formed so as to securely engage each other using a combination of recesses 183 grooves and shoulders 184 extended. The filter or membrane 164 can be held in place between the inner rigid member 181 and the shoulder 184 of the outer seal member 182. Alternatively, the filter 164 may be ultrasonically welded or otherwise secured to the rigid member 181. In still another embodiment, as shown in Figure 5D, the outer seal object 180 may comprise a unitary outer seal member 182 which may optionally be molded so as to accommodate the filter or member 164 within the retention recess 185. Figures 6A and 6B illustrate another embodiment that is very similar to that of Figure 5A, but provides a slightly different configuration for the external annular rigid body 181 and particularly the members 181a, 181b thereof. In each embodiment illustrated in Figures 5A-5D and 6A-6B, the outer seal member 182 is preferably formed of a non-reactive elastomeric material that can provide the necessary seal engagement with the inner wall of vial or compartment 150. In addition , the outer seal member 182 may optionally be lubricated with silicon or other suitable non-reaction lubricant to facilitate movement of the outer seal object 180 forwardly into the vial or compartment 150 upon receiving sufficient force as will be described. The movable seal plug 166 is preferably formed of a material, such as an elastomer or PTFE, which has low frictional properties so that the seal plug 166 can easily slide into the outer seal object 180 when the seal is activated. injector. The movable seal plug 166 may also be optionally lubricated with silicon or other suitable non-reactive lubricant. In the illustrated embodiments, and as specifically shown in Figure 6B, it is preferred that the outer annular structure 180 defines an internal surface having a smooth cylindrical configuration toward the rearwardly portion 169 thereof, and longitudinally extending slits 168. towards the front portion of it. The grooves 168 create a flow path or flow paths 167 through which the liquid in the wet compartment 151 can bypass the seal plug 166 when the plug 166 moves forward seal coupling with the surface portion 169 cylindrical toward slotted portion 168. The movement of the seal plug 166 towards the deviation area 165 opens the fluid flow path 167 between the wet portion 151 and the dry portion 152. The movable seal cap 166 preferably includes a plurality of circumferential grooves 186 to provide improved seal engagement and to facilitate the sliding action of the cap 166.

As mentioned above, preferably seal structure 160 includes the filter or membrane 164 at the end of the flow path 167 through which the liquid Injection solution can pass through the injector has been activated. The liquid injection solution then enters the dry portion 152 of the chamber 150 where it mixes with and dissolves the dried medicament. More particularly, the filter 165 disperses the liquid injection solution leaving the seal structure 160 to present laminar fluid flow to the entire surface of the dried medicament, thereby wetting the entire surface of the dried drug for rapid and complete dissolution. . The filter membrane 164 may be any structure that usually evenly distributes the liquid throughout the full diameter of the chamber 150 for dissolving dried drug. During the operation, manual activation of the actuator assembly 120 releases the collar 122 (as described above), which applies pressure to the piston assembly 170. The application of pressure on the plunger assembly 170 by the collar and spring assembly 124 moves the plunger 170 in the direction of the needle assembly 140. As a result, the entire chamber 15Q and the needle assembly 140 move forward in the housing 110 so that the needle 141 pierces through the front end of the cover 202 and exits through the forward end of the housing 110, and particularly through a hole 204 in the nose-cone portion 206 of the housing. The cover 202, which serves to hold the needle 141 sterile when the injector is in storage, also serves as a shock absorber during activation as it is generally compressed in an accordion-like manner between the nose cone 206 and the support 143 of needle When the needle 141 extends from the housing 110 and the needle chamber 150 and support 143 approaches the nose cone 206 the portion of the housing so that further forward movement the camera 150 substantially resists, the plunger 170 then begins to move forward through the chamber 150. This pressurizes the liquid injection solution placed within the wet compartment 151. With reference to Figure 6A-6B, the increased pressure within the wet compartment 151 moves the seal plug 166 from the first sealed portion where the seal plug 166 is sealingly coupled with the surface 169 of the outer seal structure 180 ( Figure 6A) to a second bypass position (Figure 6B) that allows the injection solution to flow through the flow path 167 created by grooves 1 € 8 and thus through the seal structure 160. As described above, the elevated pressure developed within the wet portion 151 in response to the movement of the collar 122 and the plunger assembly 170 forces the liquid injection solution through the seal structure 160 which dissolves the drug into a solution of medically injection that will then be forced out through needle 141 and into the patient. As the collar 122 and plunger assembly 170 continue forward, the plunger 170 will eventually contact the seal structure 160, which, in a preferred embodiment, causes the seal structure 160 to move in the direction of the assembly 140. of needle Movement of the seal structure 160 would cause any solution remaining within the portion 152 to be dispersed through the needle assembly 140, so as to reduce the amount of residual medication remaining within the chamber 150. As shown in FIGS. Figures 2A, 2B and 4, a non-filter membrane 190 is preferably provided adjacent the needle assembly 140 to prevent any particles of dry medicament from tapping the trailing end of the needle 141 prior to an injection operation. The membrane 190 may also serve to slightly restrict or slow the injection of medication towards the patient, to facilitate more complete dissolution during injection. More particularly, to prevent passage of undissolved dry medicament to the needle assembly 140, a medicament support 190 is preferably provided between the end of the dry compartment 152 and the needle assembly 140. The holder 190 can serve to prevent blocking of the needle assembly 141 by preventing the dried medicament from entering the area surrounding the needle assembly 140 while allowing the passage of the dissolved drug mixture and the liquid injection solution. The support 190 may be configured as described in the Provisional Application of E.U.A. No. 60 / 238,448, which is incorporated herein by reference in a manner consistent with this disclosure. It is contemplated that multiple carriers 190 may be placed within the dry compartment 152. The provision of the supports 190 can also improve the laminar flow of the liquid injection solution through the dried medicament., thus improving the dissolution. In addition, a diaphragm assembly (not shown) can also be provided adjacent to the drug support 190, as is known in the art. The diaphragm assembly acts to prevent the passage of the liquid injection solution to the needle assembly 140 prior to activation of the actuator assembly 120. More particularly, the diaphragm assembly will not break until the blunt end of the needle assembly 140 ruptures the expanded diaphragm or sufficient pressure builds up in the dry compartment 160 to break the diaphragm, again as is known in the art. As described above, the movement of the collar 122 causes the injection needle 141 of the injection assembly 140 to advance and protrude through the housing 110. As such, injection of the medicament can be performed with a simple operation. In sum, the user simply removes the end cap assembly 130, places the injection end of the housing 110 adjacent to the injection site, and presses the push button 132. This operation automatically triggers the operation of the drive assembly or spring 250 to advance the collar 122 causing the liquid injection solution placed within the wet portion 151 to enter the dry portion 152 through the seal structure 160. The dissolved drug is then transmitted through the injection needle 141 to provide the user with the necessary dose of medication. The automatic injector 10 according to the present invention reduces the amount of time required to administer medicament compared to other wet / dry injectors and eliminates the need for mixing by the user. The seal structure 160 allows the manufacture of a superior wet / dry auto injector with a complementary combination of components that are known in the conventional auto injectors sector or are otherwise relatively simple to manufacture. The seal structure 160 allows sufficient mixing of the wet and dry medicament components without requiring manual agitation. This mixing action is improved by the filter or membrane 164. In a preferred embodiment, the filter 164 is a hydrophobic acrylic copolymer, supported, molded on a nonwoven nylon support. Preferably it is a membrane treated with FiouRepel for higher olefinicity / hydrophobicity. In another embodiment, shown in Figure 7, the automatic injector cartridge includes a needle assembly 140 positioned within the dry portion 152. The needle assembly 140 extends within the dry portion 152 to the seal structure 180, described above with reference to Figures 5A-5D. The seal structure 180 separates the dried portion 152 from the wet portion 151. As shown in Figure 7, the cartridge further includes a plunger 170 placed therein. The plunger 170 is configured to engage the collar 122 of the activation assembly 120. The cartridge includes a cover 301. Like the cover 202, the cover 301 holds the needle 141 in a sterile environment until it projects from the end of the cover 301 in response to activation of the activation assembly 120. During the operation, the needle assembly 140 passes through the dry portion 152 as the wet medicament passes through the seal structure 180. In other embodiments (see Figures 8A and 8B), internal plug 166 is not provided. Rather, the external structure 180 is simply supplemented by a seal membrane 226 extending through the internal area defined by the internal surface of the external structure. When the chamber 150 reaches the front end of the housing during an injection operation, the pressurization of the wet compartment 151 causes the seal membrane 226 to break, thereby allowing the seal structure 160 to allow the liquid to pass through the seal. same In this modality, it may be desirable to provide the seal structure 160 with a pointed member 228 disposed adjacent the seal membrane 226 to facilitate breaking the seal membrane during pressurized expansion thereof during an injection operation. The member 232 in which the pointed member 228 is mounted has a plurality of passages 234 that allow fluid to pass therethrough. The filter or membrane 164 is preferably mounted remote from the passages 234 to present laminar or distributed flow of the dried medicament. EXAMPLES An injector according to the present invention was loaded with liquid injection solution and dried medicament and activated with the following results. Loaded Dispatched Time Dry Powder Powder Dry Fluid Operation Mg MI "O mg mi Seg 531 2.7 94 497 2.3 4.0 557 2.7 93 515 2.3 4.5 582 2.6 92 537 2.2 4.4 Other embodiments and modifications of the invention are also contemplated, for example, a cover assembly, described for example in the Patent from the USA No. 5,295,965. { whose disclosure is specifically incorporated herein by reference) can be secured to the injection end of the housing 110 after deployment of the medicament. Additionally, the automatic injector may further include a nipple plunger assembly, as described for example in the U.S. Patent. No. 5,713,866 (the disclosure of which is specifically incorporated herein by reference). In yet a further embodiment, the front dry chamber 152 contains the needle 141, as shown in Figure 7. The needle 141 is forced through a front plug retainer during the initial compression of the two-chamber system. As is known in the art, providing the needle 141 in the forward chamber 152 provides improved longitudinal compactness of the design. In still another embodiment, a syringe previously filled with the seal structure disposed between the wet and dry components is provided. In further contemplated embodiments, seal structure 160 can be used in the same type of injector as described herein, except that instead of using a dry medicament (powder) separated by a liquid component, the first liquid medicament is separated from a liquid. second fluid component by stamp structure 160. In yet another embodiment, stamp structure 160 may be used in what is known in the art as a "needleless injector" where an injection may be made to a patient without a needle or cannula. longitudinal cross-section of a chamber 350 mounted to a needle assembly 340 in accordance with a further embodiment of the invention Neither a housing 110 nor an actuator assembly 120 are shown in Figure 9, however, the chamber 350 and the assembly 340 of needle can be used with the housings 110 and actuator assemblies 120 described above or with substantially any known housing or actuator assembly In the chamber 350 and needle assembly 340 shown in Figure 9, many of the components are the same as those described above with respect to Figure 1, therefore, the above description will be sufficient for those components.As the camera 150, the camera 350 has a portion or compartment to wet and a dry portion or compartment 152. A seal structure 360 separates the wet portion 151 and the dried portion 152. The seal structure 360 includes an outer seal member 380, a movable seal plug 166, a bypass zone 165, and may also include a filter or dispersion membrane 164. Although a movable seal plug 166 is shown in Figure 9, the seal structure 360 may include a tamper-evident seal membrane 226 in place of a seal bead 166, as shown in Figures 8A and 8B. Figure 10 is a perspective view of the external seal member 380. Figure 11 is a front elevation view of the seal member 380, and Figure 12 is a sectional view of the external seal member 380, taken through Line 12-12 of Figure 11. As shown, the outer seal member 380 has an annular cleaner portion 382 that makes seal contact with the internal wall of the dry portion 152 of the chamber 350 and extends axially forward in the direction of driving movement along the longitudinal axis from chamber 350, to needle assembly 140. While the external seal members 180 described above form a seal with the inner wall of the container 150, during the driving process f the powder of the dried medicament in the dry portion 152 tends to accumulate around the member 180., 380 seal and seal / container interface. As the device is actuated, some of the dust that accumulates around the seal member 180, 380 can be urged or forced into the space between the glass and the seal member 180. The entire area around and between the seal member 180 and the inner wall of the container 150 can become a "dead space", in which the accumulated dust can not be properly mixed with fluid. The cleaner portion 382 helps to eliminate dust buildup around the seal member 380 by "cleaning" or "scraping" any dust accumulated away from the wall of the chamber 350 and directing it radially inward, where it can be mixed properly with the wet medicament portion as the seal member 380 passes through the dried portion 152. As shown in Figure 9, the cleaner portion 382 contacts the inner wall of the dry portion 152 of the chamber 350 along substantially its entire length. The degree of contact between the cleaner portion 382 and the internal wall of the dry portion 152 is possible, at least in part, because the cleaner portion 382 extends axially. While it would be possible to construct a cleaning structure that would extend radially or angularly outwardly from the main body of the seal member 380, said cleaning structure would not be in contact with the internal wall of the dried portion 152 over substantially all of its length. Therefore, it would be possible for said putative cleansing structure to cause an undesirable accumulation of drug powder, particularly if the medicament powder were to be moved beyond it to the space between it and the internal wall of the dry portion 152. . Consequently, the forwardly extending, straight cleaning portion 382 is currently preferred. A cleaning portion 382, even when shown in the embodiment of Figure 9, may be used in any of the modes shown and described above in any variations thereto. As shown in Figure 9, camera 350 has an "open mouth" configuration; that is, the container itself does not taper substantially as it meets the needle assembly 340 (eg, as compared to the embodiment shown in Figure 3A). The advantages of having an "open mouth" container are described above with respect to container 15Q. If the "mouth" of the container (i.e., the opening to the dry portion 152 of the container) is open and wide, it becomes easier to load the dry component of the medicament. However, having a tapered portion adjacent the needle assembly 340 helps direct the medicament radially inward toward the needle assembly 340 when the injection is occurring. In order to realize the advantages of an "open mouth" container and the advantages of a tapered container, the chamber 350 includes a tapered insert 384 or its mouth, just behind the needle assembly 340. Figure 13 is a perspective view of the tapered insert 384, Figure 14 is a front elevation view, and Figure 15 is a sectional view through Line 15-15 of Figure 14. The tapered insert 384 it tapers radially inwardly as it extends axially forward, so as to form a funnel portion 386 with a small central opening 388 at one end. The tapered insert 384 also has a rearwardly open end 389 with a larger open diameter. The insert 384 sealingly couples the walls of the chamber 350. Extending radially outwardly from the outer surface of the funnel portion 386 near the small central opening 388, there is an annular seal flange 390. In the embodiment shown in Figures 13-15, the annular seal flange 390 is an integral portion with the tapered insert 384. However, in some embodiments, the annular seal flange 390 can be attached to the funnel portion 386 by adhesives or other fastening methods. Additionally, as will be described in more detail below, in some configurations, the annular seal tab 390 may be absent. The insert 384 is preferably formed of a material that will not react with the dry medicament stored in the compartment 152. The chamber 350 and the needle assembly 340 includes a metal skirt, generally indicated at 392, which is laminated or stamped so as to be capturing or securing the needle assembly 340 to the front end of the chamber 350. In this embodiment, the annular seal flange 390 is fitted between the chamber 350 and the needle assembly 340 so as to form a seal therebetween. Either the annular seal flange 390 itself or, depending on the configuration, the complete tapered insert 384, an elastomeric material or other suitable rubber for sealing can be made. The tapered insert 384 can be removed from the chamber 350 to effect loading of the dried medicament and then inserted into the chamber 350 before being joined with the needle assembly 34Q. Even though the tapered insert 384 is shown with a portion 386 of radially inward taper funnel, constant, taper of tapered insert 384 can be of any type and will facilitate the flow of fluid from chamber 350 to needle assembly 340. At the forward end of the tapered insert 384, a small central opening 388 of the insert 384 is covered by a filter 190 that is positioned between the tapered insert 384 and the needle holder 343 to filter the fluids passing from the chamber 350 toward the needle assembly 340, so as to prevent any undissolved medicament from entering the needle-forward assembly 34Q of the filter 190, defined on the backward side (facing the container) of the needle holder 343 is a chamber 394 which is AJiusa radially inwards towards its front end. The chamber 394 is contoured to expose a substantial portion of the surface area of the filter 190 to the flow between the chamber 350 and the needle assembly 340. Preferably,, the chamber 394 has an opening at least as large as the small central opening 388 in the tapered insert 384. In the embodiment shown in Figure 9, the camera 394 is substantially spherical, although other configurations may be used. Chamber 394 can be seen more clearly in Figure 16, which is a longitudinal cross-sectional view of a portion of needle assembly 340. The chamber 394 allows a larger, more laminar, and more fully developed flow through the filter 19Q to the needle 141. In addition, the chamber 394 is configured to direct the flow of medicament to the needle 141. Co or is also shown in FIG. Figure 16, neither the needle 141 nor any other structure protrudes into the chamber 394. Although it would be possible to construct a chamber 394 and needle assembly so that a portion of the end of the needle protrudes into the chamber 394, said arrangement could cause flow turbulent around the end of the needle that protruded into the chamber 394, or could otherwise eliminate some of the benefits of the chamber 394. The seal member 380 with the cleaning portion 382, tapered insert 384 and chamber 394 can all be used in a wet / wet autoinjector assembly that includes two fluid drug components. In a wet / wet autoinjector assembly - a burnable membrane is typically placed over the opening of the compartment adjacent the needle assembly, in order to prevent fluid in that compartment from leaking out of the compartment and into the needle assembly. If the seal member 380, the tapered insert 384, and the chamber 394 are provided in a wet / wet autoinjector assembly, a burnable membrane can be provided as a portion of the tapered insert 384. For example, a burnable membrane could be placed in funnel portion 386 of the insert. The seal member 380, the tapered insert 384 and the chamber 394 can also be used in a wet / dry or wet / wet auto-injector assembly that does not include all of the features described above. For example, the tapered insert 384 and chamber 394 can be used in any wet / dry or wet / wet autoinjector to improve the loading and operation of the autoinjector assortment. A chamber for an autoinjector can be filled with medicament components. appropriate in various different ways. For example, a common way to fill an autoinjector chamber is to fill a first medication (eg, a moist medicament) through an opening in the chamber and then fill a second medication (eg, a medication dry) through the same opening in the chamber. This process, while common, tends to cause contamination because both wet and dry medications are filled through the same opening. For example, if a dried powder drug is filled first, any powder that accumulates around the the opening can be mixed with a subsequently filled moist medicament, thus contaminating the contents of the moist compartment. Conversely, if the moist medicament is first filled, the liquid that accumulates around the opening can be mixed with some of the subsequently filled dry medicament, thereby contaminating the contents of the dry compartment. However, using a chamber 150, 350 in accordance with the invention, it is advantageous to fill the chamber 15Q, 35Q using a separate opening in the chamber 15Q, 35Q for each type of medicament, thereby eliminating the problem of cross-contamination. This kind of filling process for a chamber 150, 350 includes a number of tasks and will be described below with respect to the chamber 350, even though the process described, in general, is equally applicable to the other modalities described above. , the filling process would be carried out in an aseptic environment. Typically, camera 350 is initially open at both ends and does not include any interior structures, as shown in Figure 17A. A seal structure, such as the seal structure 360, is first inserted, toward the ca. 350 a.m., that is placed substantially as shown in Figure 17B. Once the structure 360 is in place, the chamber 350 is removed to or placed, in a particularly low aseptic environment, and positioned so that the wet portion or compartment 151 can be filled through an opening 396 in the rear end of camera 350, as shown in Figure 17C. (The low particulate environment prevents possible cross-contamination of the wet portion 151) After the wet portion 151 is filled, the opening 396 at the rear end of the chamber 350 is sealed by installing the plunger 170, as shown in FIG. Figure 17D. Positioning the chamber 350 in a low particulate environment before filling the wet portion 151 helps to prevent contamination of the wet portion 151 by dust or other particles. Once the wet portion 151 is filled with the portion of the liquid portion 151, the liquid portion 151 is filled. desired liquid medicament and the trailing end is sealed with the plunger 17Q, the chamber 350 is removed from the low particulate environment and placed in an appropriate aseptic environment so that the dry portion or chamber 152 of the chamber 350 can be filled through an opening 398 in the front of the chamber 35Q. There are two common ways to fill the 1562 dry portion. One way to fill the dry portion 152 is to place the dry powder directly into the dried portion 152 through the opening, as shown in Figure 17E. Another way to fill the dry portion 152 is to fill the dried portion 152 with a liquid medicament through the opening 398 and then freeze the liquid medication directly into the dry portion 152 to leave only the desired dry medicament- While this filling process Liquid and freeze-dried can be used, sometimes it leaves residues in the dried portion 152, which can interfere with the stability of the dried drug or contaminate it in another way. A third way to fill the dry portion 152 is to lyophilize a liquid medicament in a separate container to form a lyophilized dry medicine tablet 400 and then deposit the dried drug tablet 400 in the dried portion 152 through the opening 398, as shown in FIG. shown in Figure 17F. This variation of the filling process is more advantageously used with a chamber having a relatively wide opening towards its dry portion, so that tablets of various sizes can be accommodated. If a chamber has a relatively narrow opening towards its dry portion, it may be necessary to fill that dry portion with powder, or to lyophilize a liquid medicament directly in the dry portion to form a dry powder. After the dried portion 152 is filled, a tapered insert 384 is placed in the opening 398 of the chamber 350 and the needle assembly 340 is secured over the tapered insert 384 ... When the process is complete, the chamber 350 is as shown in Figure 9. Even though the present invention has been described with respect to a number of modalities? These modalities are intended to be illustrative, rather than limiting. As those of ordinary experience in the field will understand, modifications and variations are possible within the scope of the appended claims.

Claims (2)

1. CLAIMS 1.- An automatic injection device that contains a load previously loaded with medication for self-administration automatically stores the medication during the actuation thereof, the device comprising: a housing; a medicament chamber disposed in the housing, the medicament chamber including a first compartment containing a portion of dry medicament, and a second compartment containing a portion of wet medicament to be mixed with the dry medicament portion; a seal structure between the first compartment and the second compartment, the seal structure being initially in a seal condition keeping the first compartment separated from the second compartment, the seal structure including: at least one flow path formed therein , and a cleaning portion disposed at the front end of the seal structure and positioned to movably couple the internal walls of the first compartment as the seal structure moves a. Through the first compartment, the cleaning portion being configured to direct dry medicament particles coupled with the inner walls radially inward as the seal structure moves through the first compartment, the seal structure being converted to a blending condition as device activation result; a needle assembly that dispenses the mixed medication portions from the medication chamber; and an activation assembly carried by the housing and including a stored energy source, wherein the activation of the activation set releases the energy stored from the stored energy source, causing the seal structure to be converted from the seal condition. to the mixing condition, and thereby causing or allowing the medicament portions to mix and be forced through the needle assembly. 2. The automatic injection device according to claim 1, wherein the first compartment the needle assembly is disposed and disposed forward of the second compartment. 3. The automatic injection device according to claim 1, further comprising an insert mounted on the front end of the chamber adjacent to the needle assembly, the insertion defining a tapered flow path tapering radially inward as which extends axially forward. 4. The automatic injection device according to claim 3, further comprising a filter placed between the drug chamber and the needle assembly. 5. The automatic injection device according to claim 4, wherein the needle assembly comprises a needle holder for mounting the needle assembly to a front end of the medicament chamber, the needle holder defining a provided chamber. adjacent to the filter on one side of the filter needle assembly. 6. The automatic injection device according to claim 5, wherein the needle support chamber adjacent to the filter has an enlarged rear end opening of a size that is at least as large as the front end opening of the device. the insertion 7. - The automatic injection device according to claim 6, wherein the needle support chamber adjacent the filter has a substantially hemispherical shape. 8. The automatic injection device according to claim 7, comprising in addition a fluid distribution member disposed between the first compartment and the second compartment _. 9. The automatic injection device according to claim 8, wherein the fluid distribution member is a filter. 10. The automatic injection device according to claim 1, wherein the seal structure comprises an outer seal structure carrying the cleaning portion, the flow path being formed in the external seal structure, and a plug member for sealing the flow path when the seal structure is in place. the condition of seal. 11. The automatic injection device according to claim 10, wherein the seal structure has an outer periphery that forms a peripheral seal with an inner wall of the medicament chamber, and wherein the cap member is radially spaced. inward from the peripheral seal that seals the at least one flow path formed in the seal structure. 12. The automatic injection device according to claim 1, wherein the cleaning portion comprises a peripheral rim having an internal surface extending radially inwardly as it extends axially rearwardly. 13. An automatic injection device that contains a charge previously loaded with medication to automatically self-administer the medication during the actuation thereof, the device comprising: an accommodation; a medicament chamber disposed in the housing, the medicament chamber including a first compartment containing a first portion of medicament, and a second compartment containing a second portion of medicament to be mixed with the first portion of medicament; a seal structure between the first compartment and the second compartment, the seal structure being initially in a seal condition holding the first compartment separate from the second compartment, the seal structure being converted to a mixing condition as a result of the activation of the device; a needle assembly that delivers the drug charge from the medication chamber, the needle assembly having a backward opening having a diameter that is less than a diameter of the medication chamber; an insert mounted at a forward end of the medicament chamber adjacent the needle assembly, the insert defining a tapered flow path tapering radially inward as it extends axially forward; an activation assembly carried by the housing and including a stored energy source, wherein the activation of the activation set releases the stored energy from the stored energy source, causing the seal structure to be converted from the seal condition to the mixing condition, and thereby causing or allowing the first and second portions of the drug to mix? they are directed by the insertion radially inward towards the backward opening of the needle assembly, and are forced through the needle assembly. 14. The automatic injection device according to claim 13, further comprising a filter placed between the drug chamber and the needle assembly, 15. The automatic injection device according to claim 14, wherein the Needle assembly comprises a needle holder for mounting the needle assembly to a front end of the medicament chamber, the needle holder defining a chamber provided adjacent to the filter on the needle assembly side of the filter, 16. The device of automatic injection according to claim 15, wherein the backward opening of the needle assembly comprises a rearward end opening in the needle support chamber adjacent to the filter, the rear end opening having a size that is when so large as the front end opening of the insert. 17. The automatic injection device according to claim 16, further comprising a fluid distribution member carried by the seal structure. 18. The automatic injection device according to claim 13, wherein the seal structure comprises an external seal structure carrying a cleaning portion, a flow path formed in the external seal structure, and a plug member. to seal the flow path when the seal structure is in the seal condition. 19. The automatic injection device according to claim 18, wherein the seal structure has an outer periphery that forms a peripheral seal with an inner wall of the inner chamber, and wherein the cap member is radially spaced. inward from the peripheral seal that seals the at least one flow path formed in the seal structure.
2. 2. The automatic injection device according to claim 19, wherein the cleaning portion comprises a peripheral rim having an internal surface that extends radially inwardly as it extends axially rearwardly. 21. An automatic injection device that contains a load previously loaded with medication to autoadminister the medication automatically during the actuation thereof, the device comprising: an accommodation; a medicament chamber disposed in the housing, the medicament chamber comprising a first compartment containing a first portion of medicament and a second compartment containing a second portion of medicament to be mixed with the first portion of medicament; a seal structure between the first compartment and the second compartment, the seal structure being initially in a seal condition that keeps the first compartment separate from the second compartment, the seal structure being converted to one. mixing condition co or result of activation of the device; a needle assembly that delivers the drug charge from the medication chamber; a filter placed between the drug chamber and the water assembly; and an activation assembly carried by the housing and including a stored energy source wherein the activation of the activation set releases the stored energy from the stored energy source, causing the seal structure to be converted from the condition of seal to the mixing condition, and thereby causing or allowing the first and second drug compounds to mix and be forced through the needle assembly; wherein the needle assembly comprises a needle and a needle holder for mounting the needle to the medication chamber, the needle holder defining a needle assembly chamber having a backward opening covered by the filter, the joint chamber needle having an inner surface that tapers radially inwardly as it extends axially forward towards a rearward end of the needle. 22. The automatic injection device according to claim 21, wherein no backward portion of the needle protrudes into the needle assembly chamber. 23. - The automatic injection device according to claim 22, wherein the needle assembly chamber has a substantially hemispherical shape. 24. The automatic injection device according to claim 23, further comprising an insert mounted at the forward end of the chamber adjacent to the needle assembly, the insertion defining a tapered flow path that radially bows inwardly to the needle assembly. as it extends axially forward. 25 ^ - The automatic injection device according to claim 24, further comprising a fluid distribution member carried by the seal structure. 26. The automatic injection device according to claim 21, wherein the seal structure comprises an external seal structure carrying a cleaning portion, a flow path formed in the external seal structure, and a plug member. for sellax the flow path when the seal structure is in the seal condition. 27, - The automatic injection device according to claim 26, wherein the seal structure has an outer periphery that forms a peripheral seal with an inner wall of the medicament chamber, and wherein the cap member is radially spaced inward from the peripheral seal that seals the at least one flow path formed in the seal structure. 28. The automatic injection device according to claim 27, wherein the first portion of medicament comprises a portion of dry medicament and a cleaning portion carried by the external seal structure is configured to direct the dried medicament particles coupled with the walls of the medicament chamber radially inward as the seal structure moves through the first compartment. 29. A method for providing a chamber containing medication of an automatic injection device, comprising: inserting a seal structure towards the chamber to divide the chamber into a frontal compartment and a rear compartment; filling the posterior chamber of the chamber with a portion of moist medicament through a posterior end of the chamber; seal the rear end of the rear compartment of the camera; fill the front compartment of the chamber with a portion of dried medication through a front end of the chamber; and seal the front end of the front compartment of the camera. 30. The method according to claim 29, wherein sealing the front end of the front compartment comprises placing a tapered insert at the front end of the chamber., the tapered insert having a tapered flow path therein, the flow path being tapered so that the diameter thereof increases as it extends rearwardly. 31. The method according to claim 30, further comprising fixing a water connection to the front end. 32. - The method according to claim 29, wherein the rear compartment of the chamber is filled with the wet medicament portion before the front compartment of the chamber is filled with the dried medicament portion. 33. The method according to claim 32, wherein the seal structure is inserted before the posterior compartment is filled with the wet medicament portion. 34. - The method according to claim 29, wherein the dried medicament portion is a powder. The method according to claim 29, wherein the dried medicament portion is a dimensioned tablet and adapted to fit through the front end of the chamber. 36. The method according to claim 35, wherein the tablet is prepared ?? lyophilizing a suspension or liquid solution containing the suspended or dissolved portion of dried medication in a separate container ^ fifteen z? 5