MXPA97004885A - A retaining assembly that has dedesviation characteristics for use on a cylinder of multi-chamber syringe - Google Patents

Abstract

A detent assembly having deflection characteristics for use in a multi-chamber syringe cylinder. The retainer assembly includes a sequential seal body responsive to fluid forces to allow for the sequential supply of different contents, such as separate fluids, held separately in the syringe barrel. The sequential seal body has a generally cylindrical side wall with a distal end, a proximal end and a longitudinal axis therethrough. The retainer assembly also includes a generally cylindrical flow channeler mounted to the distal end of the sequential seal body. The flow channel allows the reconstitution of the dry drug contained in the syringe barrel distant from the flow channel. The flow channeler has opposite and distant opposite ends and an external surface generally cylindrical between them. At least one fluid flow channel extends between the proximal and distal ends of a flow channel. A conical, remote directed projection is located at the distal end of the flow channeler to prevent accumulation of dead space between the channel and the internal shoulder located at the distal end of the syringe barrel. The retainer assembly can be employed in a multiple chamber syringe barrel that has a bypass channel to allow fluids to pass distal to the retainer assembly. The multi-chamber syringe cylinder can be separated into different chambers by means of one or more deflection seals to retain the various components intended for sequential supply by means of the assembly of ret

Description

A RETAIN ASSEMBLY THAT HAS DEFLECTION CHARACTERISTICS FOR USE ON A CAMERA SYRINGE CYLINDER MULTIPLE I. Field of the Invention. The invention relates to seals and, more particularly, to a seal assembly having deviating characteristics to promote reconstitution of a dry drug, such as a lyophilized drug, contained in a hypodermic syringe and then to promote complete sequential injection of the drugs. different contents retained in the separate chambers in the syringe barrel.

II. Background. As is known in the art, hypodermic syringes include an elongated cylinder having opposite ends proximal and distant with a chamber therebetween to receive a fluid. A passage extends through the distal end of the syringe barrel and communicates with the chamber. The distal end of the syringe barrel is connected to a penetrating member, such as a needle cannula or a blunt cannula, to deliver the fluid from the chamber and passage. The proximal end of the syringe barrel receives a plunger rod and retainer assembly. The force applied to the plunger rod drives the retainer along the cylinder to move the liquid from the chamber through the needle cannula.

Frequently, it is desired to supply a number of discrete substances contained within the chamber from the hypodermic syringe. These discrete substances must be contained normally separated from one another until such time as the supply to the patient is desired. It is necessary, then, that the chamber defined between the proximal and distant ends of the elongated cylinder be divided into a discrete number of chambers, each capable of containing the substance intended for delivery to a patient. In view of the above, it would be useful to construct a hypodermic syringe capable of simultaneously storing a drug together with any components that will be administered, with the ability to keep the drug and components separate until administration is desired. Storable medicines in hypodermic syringes can be in liquid form or in dry form. It is often desirable to store drugs in dry form since, depending on the type of medication, it will exhibit a longer storage life compared to the liquid form of the drug. As will be appreciated by those skilled in the art, one way to reduce a liquid drug to the dry form is through a lyophilization process. In this process, the liquid medicines are subjected to a freeze-drying or lyophilization process, which reduces the liquid medication to a dried powder or granulated form. For purposes of simplicity, it is intended that the reference in this patent application to a drug in lyophilized form encompass any dry medicament, which requires reconstitution prior to delivery. Frequently, dry medications are located in a multi-chamber syringe cylinder in the chamber located closest to the penetrating element. In order to administer the drug to a patient, a diluent is introduced into the chamber containing the dry medicament to reconstitute the drug to its liquid form. Subsequently, the reconstituted drug can be administered from the same multiple chamber syringe that has stored the lyophilized drug. It is also desirable to isolate the dried medicament from the environment until such time as reconstitution and delivery are desired. Taking into account the above objectives, U.S. Patent No. 4,929,230 to Frederick W. Pfleger (Pfleger '230), the disclosure of which is specifically incorporated herein by reference, discloses a particular detent construction useful for dividing the cylinder from barrel in a plurality of chambers and allows to separate the liquid contents retained by the syringe barrel to be sequentially administered to a patient. Making a particular numerical reference to the components described by Pfleger '230, a free piston (or retainer) 33 is disclosed which includes a recessed chamber 48 which confronts the end wall 23 of the syringe barrel. The chamber 48 can be made as a circularly hollow placed around the central axis of the retainer 33 (Figs 5, 6, 7) or, as shown in Figs. 9, 10 or 11, can assume a narrow configuration, flattened out of phase with the central axis of the retainer. The retainer 33 includes a closed end 34, which faces away from the end wall 23 of the syringe barrel. The closed end 34 has a smaller diameter than the internal diameter of the syringe barrel. A peripheral side wall 35 extends obliquely between the closed end 34 of the retainer 33 and a cylindrical peripheral sealing surface 36 in contact with the inner surface of the syringe barrel. The oblique side wall 35 is overlapped with a portion of the hollow chamber 48. It is established in col. 3, lines 15-17, that the oblique side wall 35 has its generally cylindrical large end, as the sealing surface 36 for sealing engagement with the syringe barrel and is set in Col. 3, lines 19-23, which the External ribs 37 help to avoid plunging the plunger as it moves in the syringe barrel. The present inventors consider that the oblique side wall 35 is cylindrically formed around the retainer and, therefore, extends around the entire circumference of the retainer. A force is generated by a closer detent 31 connected to the piston rod 30, the retainer 33 will rest adjacent to the internal shoulder 25 of the syringe barrel. The continuous movement of the retainer 31 increases the fluid forces exerted on the oblique side wall 35 to overcome the sealing forces of elastic material inherent in the retainer 33. Due to the presence of the recessed chamber 48, the oblique side wall 35 will be folded inward, allowing the fluid contents retained near the closed end 34 to advance in a distant direction through the cannula needle. Pfleger '230 is not particularly suitable for an application that requires the reconstitution of a dry drug prior to the sequential supply of other components, such as fluids, retained by the syringe barrel. For example, neither the teaching of Pfleger '230, nor the structure of Pfleger' 230, nor the structure of Pfleger '230, is adapted to allow the reconstitution of a medicament contained in the dry form in the chamber of the syringe barrel. Pfleger '230 is directed towards the sequential supply of liquid components but not to the sequential supply of a dry component. In addition, in certain hypodermic syringes of the prior art, a correct amount of liquid can remain in the syringe barrel after the detents are advanced the full length of the barrel during an injection process. In most syringes a certain residual volume remains, no matter how small, that is trapped between the end of the retainer and the needle tip, which includes the volume of the needle cannula and the volume presented at the far end of the needle. syringe cylinder. An amount of medicament may also be trapped in the area around and between the side walls of the retainer and the interior of the syringe barrel. In the case of expensive drugs and medications that require extreme precision and supply, this so-called "dead space" must be overcome by overfilling the cylinder to ensure that the proper dose is delivered. The additional medication will be discarded with the used syringe. Costs associated with dead volume can accumulate substantially. It would be beneficial to avoid wasting the drug trapped in the syringe barrel, for example, as evidenced by Pfleger '230 between the hollow end 48 of the retainer, the inner shoulder 25 located at the final distal end of the syringe barrel and the port of the syringe. exit 24, associated with the syringe cylinder. In Fig. 7 of Pfleger '230, one sees, for example, a quantity of medicament that can be held between those surfaces. Accordingly, there is a need for a sequential seal that has deviating characteristics to promote the reconstitution of a dry drug contained in a syringe barrel and which then allows the sequential injection of a series of different contents held in separate chambers in the barrel. syringe, all of which results in the reduction of the amount of drug trapped in the syringe barrel after delivery. Such detent is described herein. lll. Brief description of the invention. A retainer assembly in accordance with the present invention includes two components: (a) a sequential, piston-like responsive body responsive to fluid forces to allow sequential delivery of different contents, such as different fluids, retained separately in the syringe barrel in a location proximal to the sequential catch body; and (b) a channeler mounted to the distal end of the sequential seal body to permit reconstitution of a dry medicament, such as lyophilized medicament, contained in the syringe barrel at a location remote from the flow channel and to allow sequential supply afterwards of the different fluids retained near the sequential seal body through a fluid passage provided in the syringe barrel. The retainer assembly according to the present invention can be employed in a multi-chamber syringe barrel which is configured to retain the lyophilized medicament as well as the different fluids. The retainer assembly may be located adjacent the distal end of the syringe barrel in a manner defining a chamber located remotely from the fluid channelizer containing the lyophilized drug. One or more deflecting detents may be located in a manner close to the sequential seal body in a manner that divides the syringe barrel into separate chambers to contain the different fluids spaced apart from each other. A deflection channel is provided in the wall of the syringe barrel to allow the various fluids to pass sequentially between their respective chambers and through the fluid flow channels defined on the flow channel for delivery through the passageway of the syringe barrel . The sequential seal body has a generally cylindrical side wall with a distal end, a proximal end and a longitudinal axis therethrough. An elongated hollow chamber is positioned within the interior of the sequential seal body. Preferably, the elongated hollow chamber is positioned towards one side of the longitudinal axis of the sequential detent body. The elongated hollow chamber includes a distal end, a proximal end and may include an opening communicating with the distal end of the sequential detent body. One or more sealing elements are positioned circumferentially around the side wall of the sequential seal body. The circumferential sealing elements may be formed as a plurality of rings formed circumferentially around the piston-like sequential seal body. The retainer assembly of the present invention includes the structure designed to reconstitute a lyophilized medicament and to substantially direct all fluids contained near the retainer assembly in a distal direction for substantially complete delivery to a penetrating member attached to the distal end of the cylinder. of syringe. For this purpose, a pair of sealing elements are arranged longitudinally along the side wall of the sequential detent body in a relation preferably parallel to the longitudinal axis. The pair of longitudinal sealing elements are each located along the side wall and separated by a distance at least equal to, if not slightly greater than, the maximum width defined by the elongated hollow chamber formed within the sequential catch body. . In a preferred embodiment, the cylindrical side wall and / or the circumferential sealing elements of the sequential seal body are widely in fluid-tight contact with the inner surface of the syringe barrel. However, a portion of the cylindrical side wall is recessed from the inner surface of the syringe barrel to provide means for exerting fluid pressure on a portion of the circumferential side wall to cause only that portion of the circumferential side wall to fold towards the hollow chamber, thereby establishing a fluid conduit between the distal and proximal ends of the sequential seal body. In a preferred embodiment, the recessed portion of the cylindrical side wall is formed as an oblique surface adjacent the proximal end of the detent body that is located between the pair of longitudinal sealing elements. The flow channel includes at least one fluid flow channel extending between the proximal and distal ends of the flow channel. In a preferred embodiment, one or more flow channels are provided helically around the flow channel. The fluid flow channels communicate the fluid that passes distally from the sequential seal assembly to the passageway of the syringe cylinder. A substantially tapered, remotely directed projection is located on the far end of the flow channel. The substantially conically shaped, remotely directed projection may be sized to substantially conform to the shape assumed by the internal shoulder located at the distal end of the syringe barrel. In use, the force of fluid exerted on the proximal end of the sequential seal body causes the sequential passage of the different fluids which are contained near the sequential seal body through the fluid channel of the syringe cylinder and the channels of the sequential seal. Flow channelizer flow. The medication is reconstituted and supplied from the chamber located distant from the flow channel. Continuous fluid pressure on the proximal end of the sequential seal body will eventually cause the flow channel to settle adjacent the distal end of the syringe barrel. The substantially tapered, remotely directed shape substantially conforming to the shape of the inner shoulder located at the distal end of the syringe barrel prevents excessive accumulation of fluid in that area. Once the flow channel is seated against the distal end of the syringe barrel, the increased fluid force exerted on the recessed portion of the cylindrical side wall of the sequential stop body causes the portion of the side wall located between the longitudinal sealing elements are folded towards the hollow chamber. The folding of the side wall in this area initiates a fluid conduit between the proximal and distal ends of the sequential seal body generally restricted to that portion of the cylindrical side wall of the sequential seal body located between the longitudinal sealing elements to allow the Sequential supply of a second liquid contained near the seal assembly. The longitudinal sealing elements, together with the portion of the circumferential sealing elements not located between the longitudinal sealing elements, remain in fluid-tight contact with the syringe cylinder. Accordingly, it is substantially prevented that fluid accumulates around the cylindrical side walls of the sequential seal body or between the substantially tapered, remotely directed projection and the corresponding distal end of the syringe cylinder, so that the fluid it is substantially complete directed through the fluid conduit for delivery through the fluid flow channels of the flow channel and out of the penetration member attached to the distal end of the syringe cylinder.

IV. Brief Description of the Drawings. The invention will now be described in greater detail by reference to the accompanying drawings, wherein: Figure 1 is a perspective view of a syringe assembly employing the retainer assembly in accordance with the present invention; Figure 2 is an exploded perspective view of the retainer assembly in accordance with the present invention, illustrating the sequential seal body and the flow channel; Figure 3 is a cut-away view of the retainer assembly of the present invention, taken along line 3-3 of Figure 2; Figure 3A illustrates another way of providing a recess in the side wall of the sequential detent body; Figure 4 is a bottom view of the sequential detent body illustrated in Fig. 2; Figure 5 is a top view of the sequential detent body illustrated in Fig.2; Figure 6 is a cross-sectional view of the syringe assembly of Figure 1 before starting an injection sequence, illustrating the syringe assembly containing the drug in its lyophilized form as well as the different contents held in separate chambers.; Figure 7 is a second cross-sectional view of the syringe assembly of Fig. 1 illustrating the delivery of a diluent from one of the separated chambers through the diverter channel of the syringe barrel and the fluid flow channel of the tubing flow to reconstitute the lyophilized medicament during an injection sequence; Figure 8 is a third cross-sectional view of the syringe assembly of Fig. 1, illustrating the delivery of the non-reconstituted medicament from the passage of the syringe barrel and the distant movement of a flow agent from its chamber within the adjacent chamber previously occupied by the diluent; Figure 9 is a fourth cross-sectional view of the syringe assembly of Fig. 1, illustrating the complete location of the flow agent in the chamber previously occupied by the diluent; Fig. 10 is a fifth cross-sectional view of the syringe assembly of Fig. 1, illustrating the total seat of the flow channel against the distal end of the syringe barrel and the folding of the cylindrical side wall of the sequential catch body. between the longitudinal sealing elements to establish a fluid conduit between the proximal and distal ends of the sequential seal body so that the flow agent is supplied to the fluid flow channels of the flow channel for delivery through the passage of The syringe; Figure 11 is a sixth cross-sectional view of the syringe assembly of Fig. 1, illustrating the end of the injection sequence; and Figure 12 is a partial cross-sectional view of the syringe assembly of Figure 1, illustrating the placement of different components at the end of the injection sequence.

V. Detailed Description of the Preferred Modality. A convention used in this patent application is that the term "distant" refers to an end closer to the needle end of a syringe barrel, whereas the term "proximal" refers to an end remote from the needle end of the barrel. syringe cylinder. Turning now to the drawings, in which similar numbers denote similar components, Figures 2-5 denote a mode 200 of the retainer assembly in accordance with the present invention. Figures 1 and 6-12 illustrate retainer assembly 200 in conjunction with a multiple chamber syringe cylinder 100. Figures 6-12 particularly illustrate the use of retainer assembly 200 in the reconstitution of a retained "M" lyophilized medicament. distally of the retainer assembly, together with the sequential supply of the different contents held in separate chambers defined near the retainer assembly 200. For ease of explanation, the details of the retainer assembly 200 will be explained first., the use of the seal assembly will continue in conjunction with the multiple chamber syringe cylinder. Turning now to Figures 2-5, the retainer assembly includes a sequential seal body 201 and a flow channel 225. The sequential seal body 201 includes a proximal end 204, a distal end 206 and a cylindrical side wall 202 that it extends between them. The sequential seal body is characterized by the longitudinal axis 208. Similarly, the flow channel 225 has a proximal end 226, a distal end 228, and one or more fluid flow channels 238 extending therebetween. The construction of the flow channel 225 is analogous to that described in U.S. Patent Application No. 5,489,266"Syringe Asembly and Method for Lyophilizing and Recosntituting Injectable Medication", the disclosure of which is specifically incorporated by reference herein. Figures 2-5 illustrate that the seal assembly 200 is formed into separate components, viz., A sequential seal body 201 and a flux channeler 225, which are cooperative coupling structure connected. For example, a projection 242 may be provided from the distal end 206 of the sequential detent body that is configured for insertion within the opening 240 that is defined on the distal end of the flow channel. The projection may include a slot 224 configured to engage one or more protuberances 246 defined within the opening. Of course, it will be understood that the positioning of the projection and the opening can be reversed between the sequential detent body 201 and a flow channel 225, such as the location of the groove and the protuberances. The resulting connection will result in the secure attachment of the sequential seal body 201 to the flow channel 225. Another cooperative structure for securing the sequential seal body to the flow channel through adhesive bonding is also within the purview of the invention. Further, if desired, the sequential seal body 201 and the flow channel 225 can be configured for releasable coupling contact, providing a threaded interface between the projection 242 and the opening 240. Likewise, if desired, the seal assembly 200 can be formed in a unitary form from a component, instead of the separation provided by the sequential seal body 201 from the flow channel 225. Returning now more particularly to the sequential seal body 201, a plurality of sealing elements they may be provided on the sequential seal body for fluid-tight contact between the sequential seal body and the inner surface 140 of the syringe cylinder 100 (see Figures 1 and 6-12). One or more circumferentially placed sealing elements 210 are provided around the cylindrical side wall 202. In the embodiment illustrated herein, four such circumferential sealing elements 210a are illustrated. Here, a closer circumferential sealing element 210b is located adjacent the proximal end 204 of the sequential seal body, so that fluid can be prevented from accumulating between the cylindrical side wall 202 and the inner surface 140 of the syringe cylinder 100 in the proximal area of the circumferential sealing elements 210a, the same positioned intermediate the proximal and distal ends of the sequential seal body 201. Those skilled in the art will recognize that any number of circumferential sealing elements can be selected in accordance with the size of the seal. catch and as needed or desired. The sequential seal body 201 includes an elongated hollow chamber 220 positioned in a direction that is preferably substantially parallel to the longitudinal axis 208. As best seen in FIG. 3, the elongated hollow chamber 220, which can assume a flattened shape, is preferably non-concentric with the longitudinal axis 208 and is preferably positioned adjacent the cylindrical side wall 202. The hollow elongate chamber 220 has a proximal end 221 located within the interior of the sequential detent body and a Distant end 223. The purpose of the elongated hollow chamber 220 is analogous to that of the hollow chamber 48 of Pfleger '230, as previously described. As shown herein, it is contemplated that because of the molding tooling conventionally employed to form the sequential seal body 100, the distal end 223 of the chamber will communicate with the distal end 206 of the sequential seal body 201 by means of an aperture. 222. However, one skilled in the art will understand that the elongated chamber 220 can be formed by other means so that it is entirely within the sequential seal body without an opening 222. A feature of the detent assembly 200 in accordance with the present invention is that it has the structure designed to minimize a quantity of medicament that would be trapped between the seal assembly 200 and the syringe cylinder 100 and that would otherwise be wasted when the syringe cylinder was discarded after use. For this purpose, the sequential seal body 201 has a pair of longitudinal sealing elements 212 preferably positioned on the side wall 202 in substantially parallel relation to the longitudinal axis 208. As best seen in Figures 2, 4 and 5, the longitudinal sealing elements 212 are separated from one another on the cylindrical side wall 202 by a distance "Y" which is equal to, if not slightly greater than a maximum width "W" exhibited by the elongated hollow chamber 220. For the purposes of this patent application, a reference to a portion or area of the cylindrical side wall 202 that is located between the longitudinal sealing elements 212 will mean that portion or area of the cylindrical side wall 202 that is encompassed by the distance "Y" "which separates the longitudinal sealing elements. As will be apparent from the following description of the operation of the retainer assembly 200 in an injection sequence (Figures 6-12), upon full settlement of the flow channel 225 against the internal shoulder 302 of the syringe barrel, it will be required to start a fluid conduit between the proximal and distant ends 204, 206 of the sequential seal body 201 so that a last remaining distinct content retained near the seal assembly 200 will be allowed to pass between the proximal and distal ends of the sequential seal body and through of the channels 238 of the flow channel 225 for delivery through the passage 108 of the syringe 100 (see Figures 10-12). For this purpose, it is an aspect of the detent assembly 200 in accordance with the present invention to initiate a fluid conduit 310 between the proximal and distal ends of the sequential detent body only in the area of the cylindrical side wall 202 located between the elements of longitudinal seal 212. The sequential seal body 201 is positioned for fluid-tight, sliding relationship with the inner surface 140 of the syringe barrel 100, as illustrated herein, by the fluid-tight, sliding relationship between the circumferential sealing elements 210a , by the internal surface 140 of the syringe barrel. One way to initiate the fluid conduit is to separate a portion of the cylindrical side wall 202 that is adjacent the proximal end 204 and between the longitudinal seal elements 212, so that this portion of the cylindrical side wall is not in watertight contact with the seal. fluid with the inner surface 140 of the syringe barrel. In this manner, the applied fluid force can act on the portion of the cylindrical side wall 202 located within the sealing elements 212 to fold that portion of the side wall toward the hollow chamber 220. A way of separating a portion of the cylindrical side wall 202 of the inner surface 140 of the syringe barrel 100 is to provide a recess in the side wall, substantially aligned with the longitudinal axis 208, in an area located between the longitudinal sealing elements 212 and the adjacent proximal end 204 (Figure 3A). In the seal assembly mode illustrated in Figs. 1-3, the side wall is separated from the inner surface of the syringe barrel by providing an oblique surface 214 on the cylindrical side wall 202, adjacent the proximal end 204 of the retainer, in an area between the longitudinal sealing elements. The oblique surface 214 extends obliquely outwardly on the cylindrical side wall 202 from the proximal end 204 towards the nearest circumferential sealing elements 210a. The regulatory consideration is that a portion of the side wall is separated from the inner surface of the syringe barrel so that the fluid has access to that area of the side wall. It will be noted that due to the presence of the recess 215 or the oblique surface 214, the sealing element 210b is only partially circumferentially positioned around the sequential detent body so that it does not extend between the longitudinal sealing elements 212. A feature Additional to the retainer assembly 100 in accordance with the present invention is that it prevents the accumulation of fluid between the distal end 228 of the flow changer.225 and the internal shoulder 302 associated with the syringe barrel 302 associated with the syringe barrel 100. (see Figures 6-12). For this purpose, the flow changer 225 has a conically shaped projection, directed in a distant manner 230 on the distal end 228. As it is described here as a cone, it will be understood that the conical projection 230 can assume any shape that generally approaches a cone. The tapered projection 230 is characterized by a base 236 that is inserted with the distal end 228 of the flow channel and has a pointed tip 234 and a wall portion 235 extending between the pointed tip and the base. It will be noted that the shape and dimensions of the conically shaped, remotely directed projection 230 are preferably shaped to conform to the shape assumed by the inner shoulder 302 in a manner that minimizes any dead space between them that would otherwise entrap the fluid. Those skilled in the art will appreciate that it may be difficult to control the shape or dimensions associated with certain portions of the syringe barrel 100. For example, a particularly difficult area to control is the bottom shape of the syringe barrel such as in the shoulder internal 302. Accordingly, if desired, the structure can be incorporated on the conical projection 230 to respond for any tolerance or shape differences in the distant shoulder 302. Referring to Fig. 2, the shape projection conical 230 may optionally present one or more discontinuities, such as one or more raised ribs 250 which act to prevent immediate sealing of fluid passage 108 in the area of internal shoulder 302. Consequently, any liquid trapped in the dead space between inner shoulder 302 and conical projection 230 may travel along the raised ribs 250 to through the fluid passage 108 for delivery by the needle cannula 400 attached to the distal tip 104 of the syringe barrel (see Figures 6-12). The raised ribs can be designed to tend to fold at the end of the injection phase, allowing substantially complete surface contact between the wall portion 235 of the conical projection and the distal shoulder 302 of the syringe barrel to ensure that nothing remains caught between them. The person skilled in the art will understand that the slots may be employed instead of, or in combination with, the ribs 250. Turning now to Figures 6-12, the operation of the detent assembly 200 in conjunction with the multi-chamber syringe cylinder 100 will now be described. The syringe barrel 100 has an open proximal end 102, a closed distant end 104 and a substantially cylindrical chamber wall 106 that is spread between them. The syringe barrel 100 (more specifically chamber wall 106) includes the aforementioned inner surface 140 which defines a fluid receiving compartment within the syringe barrel. The detent assembly 200 is preferably located within the syringe barrel 100 at an intermediate location at the proximal and distal ends 102, 104, to define a remote chamber 130 of the flow channel 225 that contains a quantity of lyophilized medicament "M" intended to be reconstituted. A cannula assembly 400 may be attached in a conventional manner to the distal end 104 of the syringe barrel so as to be in communication with the syringe passage 108. It will be understood that, if desired, various sealing means may be incorporated in the passageway 108. and / or with the needle cannula 400 to isolate the drug "M" until the injection is desired. Close to the sequential seal body 201, the sequential syringe cylinder 100 is separated into one or more separate chambers, each capable of retaining different components in isolation until the moment at which the injection sequence starts. In the embodiment described herein, the portion of the syringe barrel 100 located near the sequential catch body 201 is separated into two chambers 132, 134 by a splitter deviation catch 120. The diverting pad 120 includes a proximal end 122, a distal end 121 may be of conventional construction for a fluid-tight, sliding relationship with the inner surface 140 of the syringe barrel. The chamber 132 may contain a "D" diluent which will be used to reconstitute the lyophilized medicament "M", while the chamber 134 may contain an "F" flow agent which will help to remove substantially all of the reconstituted medicament (" M + D ") from the syringe barrel so that it can be delivered through passage 108. As will be apparent to the person skilled in the art, by appropriately configuring the dimensions of the syringe barrel and its components, as well as the location of the deflection 110 on the syringe barrel (see below), the portion of the Cylinder d, e jé'ríricj.a 100 located near the sequential catch body 201 can be divided into as many separate chambers as desired and consequently, it holds the desired number of different substances, using an appropriate number of deflecting detents 120. In order to exert force during the injection phase, a piston seal 114 is located embedded inside the syringe barrel 100 in fluid-tight relation to the inner surface 140. A plunger rod 116 may be threadedly connected to the plunger stop 114, with a wing plate 118 provided at the other end of the plunger rod 116. A tab 107 may be formed around the open proximal end 102 of the syringe barrel to allow digital handling of the syringe barrel during use. The syringe barrel 100 has a deflection 110 in the cylindrical side wall 106 of the syringe barrel. The deflection 110 defines a fluid deflection channel 112. The fluid deflection channel 112 provides a gap in what would otherwise be the fluid-tight contact between the circumferential sealing elements 210a, b of the sequential seal body ( as well as the sealing elements associated with the deflection retainer 120) and the internal surface 140 of the syringe barrel as the detent assembly 200 and the sequential seal 120 are driven in the distal direction toward the shoulder 302. The deflection channel of fluid 112 allows the passage of fluid contained near the sequential seal body within medicament chamber 130 by means of fluid flow channels 238 established within a fluid channeler 225. As will become more apparent hereinafter, the dimensions of the different components and their placement within the syringe barrel 100 is such that the diverting channel 112 serves as a fluid conduit for all the fluid contained near the sequential catch body 201'separated from the nearest fluid content inside the syringe cylinder. Here, the closest of the fluids is denoted by the flow agent "F" located inside the chamber 134. At that moment in which all the fluids apart from the closest fluids have been driven into the chamber medicament 130 and beast of passage 108, the closest retained fluid will be located in the syringe barrel at a point distant from the diverting channel 112. At that point, the fluid pressure will be exerted on the oblique surface 214 of the body of sequential seal 201 to open fluid conduit 310, as will be described hereinafter. The sequence of an injection employing a retainer assembly 200 in accordance with the present invention is now explained, in Figure 6, the syringe 100 includes a load of lyophilized medicament "M" in the chamber 130. A diluent filler "D "is located in a chamber 132 defined within the syringe barrel 100. A flow agent charge" F "is located in the chamber 134, bounded by the chamber 132 by means of a deflection stopper 120. The plunger stopper 114 it is located in the proximal limit of the chamber 134. In Figure 7, a user has initiated an injection sequence by starting to move the plunger rod 116 in the "Z" direction. The force exerted by the user on the plunger rod 116 causes the piston detent 114 to move the flow agent "F", the deflection retainer 120, the diluent "D" and the retainer assembly 200 in the distal direction. At some stage of the injection sequence, the circumferential sealing elements 210 will find the deflection channel 112. This will open the deflection channel 112 to the diluent "D", allowing the diluent "D" to pass through the deflection channel 112. and passing through the fluid flow channels 238 of the flow channel to enter the drug chamber 130. The helical arrangement of the fluid flow channels 238 causes a turbulent action of the diluent "D" entering into the drug chamber 130. The turbulence of the diluent "D" promotes the complete reconstitution of the drug load "M". As soon as all the "D" diluent has been transferred into the drug chamber 230, the proximal end 204 of the sequential catch body and the distal end 121 of the diverter seal will be in contact. At this point, due to the force directed remotely, continuing over the deflection retainer, the retainer assembly 200 will move more distally to begin the injection of the reconstituted medicament "M + D".

The Figure illustrates a continuous application of the plunger rod user 116 in the Z direction. It will be noted that the detent assembly 200 has passed completely away from the deflecting channel 112, while the proximal end of the diverter seal 120 has past just distant from the start of divert channel 112. At this point, the reconstituted drug "M + D" in chamber 230 continues to be delivered through passage 108 of syringe barrel 100. At the same time, the flow agent "F" passes from the chamber 134 through the diversion channel 112 to enter the chamber 132 that previously contained the diluent "D". Figure 9 illustrates the continued injection of the reconstituted drug "M + D". The flow changer 225 is not yet seated against the distal inner shoulder 302 of the syringe barrel. The continued distal movement "Z" of the plunger rod 116 has forced all the flow agent "F" into the chamber 132, so that the proximal end 122 of the deflection stop and the plunger stop 114 are now in contact . Figure 10 illustrates the substantial completion of the injection phase involving the reconstituted drug "M + D". It will be noted that the flow channeler 225 is now seated adjacent the distal shoulder 302 of the syringe barrel. The force continues to be driven on the piston seal 114 / deflection retainer 120, pushing the charge of the flow agent "F" against the sequential seal body 201. It will be noted that at this point, the dimensions of the different components are such that the detent assembly 200 is located remote from the deflection channel 112, so that the circumferential sealing elements 210 of the sequential detent body are in full contact with the internal surface 140 of the syringe barrel. In order to expel the flow agent "F", it is necessary to create the fluid conduit 310 within the sequential seal body 201. Referring to Figures 2-5 and 10-12, after the conical projection 230 is seated adjacent the inner shoulder 302 of the syringe barrel 100, the continuous fluid force exerted on the proximal end 204 of the sequential catch body will be directed toward the area of the oblique surface 214. The absence of the circumferential sealing element 210b between longitudinal sealing elements 212 causes the fluid (here, the flow agent "F") to exert the force on the oblique surface 214. It will be noted that the circumferential sealing elements 210 (particularly the circumferential sealing element 210b) and the elements longitudinal seal 212 remain in sealing contact with the inner surface 140 of the syringe barrel, in a manner that prevents fluid from being directed between the internal surface 140 of the syringe barrel and cylindrical side wall 202 of the sequential catch body. The continuous fluid force exerted by the flow agent "F" on the oblique surface 214 causes the oblique surface to fold towards the elongated recessed chamber 220. The folding of the oblique surface 214 towards the recessed chamber drives the folding of the portion of the side wall 202 between the longitudinal sealing elements. Particularly, the sections 210c of the sealing elements 210a (the sections 210c are the portions of the sealing elements 210a placed between the longitudinal sealing elements 212) will be separated from contact with the inner surface 140 of the syringe barrel 100. When making sure that the longitudinal sealing elements 212 are spaced a sufficient distance "Y" from the maximum width "W" of the chamber 220, the longitudinal sealing elements 212 will remain in fluid-tight contact with the internal surface 140 of the syringe barrel . As seen in Figures 10-12. The effect of folding the oblique surface 114 and separating the sections 210c from the inner surface 140 of the syringe barrel is to create a fluid conduit 210 between the proximal and distal ends.206 of the sequential catch body. The fluid conduit 310 is substantially restricted to an area of the side wall 202 defined between the longitudinal seal elements 212. The flow agent "F" located near the sequential seal body 201 will therefore pass through the fluid conduit. 310 and will enter the fluid flow channels 238 of the flow channel 225. The flow agent "F" will pass away from the channelizer 225 for delivery through passage 108. The flow agent "F" serves to remove the reconstituted medicament. residual "M + D" remaining in chamber 130, so that the reconstituted medicament is supplied substantially complete to the patient. The flow agent "F" located near the sequential seal body 201 can pass only distant from the sequential seal body via the fluid conduit 310. By preventing the accumulation of fluid between the cylindrical side wall 202 of the sequential seal body and the internal surface 140 of the syringe barrel and substantially eliminating the dead space between the distal shoulder 302 of the syringe barrel and the distal end 228 of the flow channel and providing an individual fluid conduit 310 between the proximal and distal end of the retainer body sequentially, substantially all of the fluid contained near the remote directed seal assembly is supplied through a passage 208 through the penetrating member 400. The longitudinal and circumferential sealing members of the sequential seal body 210 may be made of the same material that forms the sequential catch body. The sequential seal body 201 and the flow channel 225 are preferably formed from suitable elastomeric materials, such as rubbers or thermoplastic elastomers or other materials known to those skilled in the art to be suitable for forming syringe detents. The same is true for the deviation detent 120 and the piston seal 114. The different seals and their associated components can be formed to suitable dimensions to accommodate various sizes of syringes found in practice. Those skilled in the art will also appreciate that various lubrication treatments, such as silicone application treatments, various coating treatments such as spray treatments or different film forming treatments such as PTFE film forming treatments, can be applied to any of the detents to improve the sliding performance within the syringe barrel as needed or desired. Those skilled in the art will appreciate and understand that additional forms of the invention can be devised without departing from the spirit and scope of the invention of the appended claims, without the invention being limited to the specific embodiments shown.

Claims (15)

1. A retainer assembly that allows the reconstitution of a dry drug retained in a syringe barrel and that allows substantially complete sequential delivery of the various contents held separately in the syringe barrel, comprising: a sequential catch body responsive to the fluid forces to allow the sequential supply of the different contents held separately in the syringe barrel, the sequential catch body having a generally cylindrical side wall with a distal end, a proximal end and a longitudinal axis therethrough; and a generally cylindrical flow channeler mounted to the distal end of the sequential seal body to allow reconstitution of the dried medicament retained in the syringe barrel distant from the flow channel, the flow channel having proximal and distant ends and an external surface. generally cylindrical extending therebetween, at least one fluid flow channel extending between the proximal and distal ends of the fluid channelizer and a conically directed projection located at a distance on the distal end of the flow channel.

2. The retainer assembly of claim 1, wherein the sequential seal body and the flow channel are formed as a unitary component.

The retainer assembly of claim 1, wherein the sequential seal body and the flow channel include the cooperative structure so that the sequential seal body is attached to the flow channel.

The seal assembly of claim 3, wherein the cooperative structure comprises at least one opening at the proximal end of the flow channel and at least one projection at the distal end of the sequential seal body, the projection coupled to the opening for mounting the flow channel to the sequential seal body.

The seal assembly of claim 1, wherein at least one fluid flow channel includes a plurality of fluid flow channels.

The detent assembly of claim 5, wherein the plurality of fluid flow channels are helically oriented around the flow channel from the distal end thereof to the proximal end thereof.

7. The detent assembly of claim 1, wherein the sequential seal body further comprises: an elongated hollow chamber positioned within the sequential seal body, the hollow chamber having a distal end, a proximal end and a width; at least one circumferential sealing element positioned circumferentially around the cylindrical side wall of the sequential seal body for sealing engagement with the inner surface of the syringe barrel; a pair of longitudinal sealing elements positioned longitudinally along the side wall of the sequential seal body in parallel relation to the longitudinal axis for sealed engagement with the inner surface of the syringe cylinder, the pair of longitudinal sealing elements spaced apart throughout of the side wall by a distance at least equal to the width of the hollow chamber; and a recessed surface provided on the cylindrical side wall of the sequential seal body, the recessed surface located adjacent the proximal end of the sequential seal body and between the pair of longitudinal seal elements; wherein in response to the fluid pressure exerted on the proximal end of the sequential seal body, the recessed surface will allow the portion of the side wall located between the pair of longitudinal seal elements to be folded toward the hollow chamber, the elements of longitudinal seal that remain in fluid-tight contact with the syringe barrel, to provide a fluid passage between the proximal and distal ends of the sequential seal body limited to that portion of the side wall between the longitudinal seal elements to substantially direct all he, fluid retained near the sequential seal body to at least one fluid channel of the fluid channel.

The seal assembly of claim 7, wherein the recessed surface comprises an oblique surface.

The retainer assembly of claim 1, wherein at least one circumferential sealing element comprises a proximal sealing element positioned adjacent the proximal end of the sequential seal body.

The retainer assembly of claim 9, wherein the proximal circumferential seal member is partially circumferentially positioned around the detent body.

11. The detent assembly of claim 1, wherein the projection of tapered, directed-away form comprises a tip, a base located adjacent the distal end of the detent body and a wall portion extending therebetween.

The retainer assembly of claim 11, wherein the projection of a tapered, directed away form further comprises one or more discontinuities on the wall portion.

The retainer assembly of claim 12, wherein one or more of said discontinuities comprises one or more ribs.

The retainer assembly of claim 12, wherein one or more of said discontinuities comprises one or more grooves.

15. A retainer assembly for allowing the reconstitution of a dry drug retained in the syringe assembly and for permitting the complete substantially complete supply, subsequent to the different contents retained by the syringe assembly, comprising: a syringe cylinder having a proximal end, a distal end a substantially cylindrical chamber wall extending therebetween to define a fluid receiving compartment, the fluid receiving compartment separated into at least two separate chambers to separately retain the different contents, a passage that extends through the far end; a piston seal dimensioned for fluid-tight coupling of the syringe barrel, the piston seal having opposite and distant ends; a retainer assembly for allowing the reconstitution of the dry medicament and the substantially complete supply, subsequent to the different contents retained by the syringe barrel, the retainer assembly located in the fluid receiving compartment at a location distant from the piston retainer, the plunger assembly comprising (a) a sequential seal body responsive to fluid forces to allow sequential supply of the different contents held separately in the syringe barrel, the sequential seal body having a generally cylindrical side wall with a distal end, a proximal end and a longitudinal axis therethrough, and (b) a generally cylindrical flow channeler mounted to the distal end of the sequential seal body to permit reconstitution of the dried drug retained in the syringe barrel, flux changer that has opposite and distant opposite ends and a supe external generally cylindrical surface extending therebetween, at least one fluid flow channel extending between the proximal and distant ends of the flow channel and a conical-shaped projection, directed at a distance located on the far end of the channeling of flow; the dried drug retained in the syringe barrel distant from the flow channel; at least one deflection stop located intermediate the plunger stop and the stop assembly for separating the fluid receiving compartment within at least two separate chambers; and a deflection channel provided in the cylindrical side wall of the syringe barrel to allow the different contents retained by at least two separate chambers to pass distally of the retainer assembly for delivery through the passageway at the distal end of the syringe barrel. SUMMARY A detent assembly having deflection characteristics for use in a multi-chamber syringe cylinder. The retainer assembly includes a sequential seal body responsive to fluid forces to allow sequential supply of different contents, such as different fluids, separately retained in the syringe barrel. The sequential seal body has a generally cylindrical side wall with a distal end, a proximal end and a longitudinal axis therethrough. The retainer assembly also includes a flow changer generally cylindrical mounted to the distal end of the sequential seal body. The flow channel allows the reconstitution of the dry drug contained in the syringe barrel distant from the flow channel. The flow channeler has opposite and distant opposite ends and an external surface generally cylindrical between them. At least one fluid flow channel extends between the proximal and distal ends of a flow channel. A conical projection, remote directed is located at the far end of the flow channel to avoid accumulation of dead space between the channel and the internal shoulder located at the distal end of the syringe barrel. The retainer assembly can be used in a multiple chamber syringe cylinder having a bypass channel to allow the fluids to pass distal to the seal assembly. The multiple chamber syringe cylinder can be separated into different chambers by one or more bypass detents to retain the various components intended for sequential supply by the seal assembly.