CA1297751C - Drug delivery cartridge with protective cover - Google Patents

Abstract

Abstract of the Disclosure A cartridge 444, 644, 744 is adapted for mounting upon a receptacle 442, 642 in a parenterial fluid administration set 420 for delivering a drug or other beneficial agent to a patient. The cartridge 444, 644, 744 includes a beneficial agent-containing chamber 606 slidable from a first, pre-use position to a second, post-use position. The cartridge includes a hollow tube 496 in which the chamber 606 is at least partially mounted. At least one cannula 500 is mounted to the hollow tube and extends opposite the chamber. A protective cover or cap 530 maintains a chamber protective position that prevents inadvertent movement of the chamber that would accidentally engage the cartridge chamber with flow path means, such as the cannula. The cover is removed in order to engage the chamber. After delivery of the agent to the patient, the cartridge is removed from the receptacle 442,642 and the cover 530 is selectively moved to a cannula protective position in which the cover 530 is securely mounted about the second, opposite end of the hollow tube, covering the cannula 500.

Description

Technical Field of the Invention .

The Dresent invention is related to the delivery of a Deneficial agent to a patient and is more particularlY directed to a deliverv system for introducing a beneficial agent into a fluid conduit.

Background of the Invention 10Many drugs are mixed with a diluent before being delivered intravenouslv to a Datient. The diluent may be, for example, a dextrose solution, a saline solution or even water. Many such drugs are suDPlied in powder form and Dackaged in glass vials or amPUles.
Other drugs, such as some used in chemotheraDv, are Dackaged in 5 glass vials or amDules in a liquid state.
powdered drugs may be reconstituted in a well known manner, utilizing a syringe which is used to inject liquid into the vial for mixing, the syringe eventually withdrawing the mixed solution from the vial. When a drug must be diluted before delivery to a Patient the drug is often injected into a container of diluent after it is reconstituted, where the container maY be connected to an administration set for delivery to a Datient. More sDecificallv, the diluent is often Packaged in glass bottles, or flexible Plastic containers such as are sold under the names MINI-BAG'n AND VIAFLEX~
by Baxter Healthcare Corporation of Deerfield, Illinois, These containers have administration ports for connection to an administration set which delivers the container contents from the container to the Datient. The drug is tvDicallv added to the container through an injection site on the container.
30Drugs maY be Dackaged separatelv from the diluent for various reasons. One of the most imDortant reasons is that manY

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drugs do not retain their chemical and physical stability when mixed with a diluent and thus cannot be stored for anV substantial period of time. Also, drugs are often Packaged seoarately from the diluent because manY firms which manufacture drugs are not engaged in the business of Droviding medical fluids in containers for intravenous delivery, and vice versa.
Therefore, a doctor, nurse, pharmacist or other medical Dersonnel must mix the drug and diluent. This Dresents a number of Droblems. The reconstitution r,rocedure is time consuming and requires aseDtic technique. The oPerator must provide the proper diluent and a syringe before beginning. Often the Powdered drug is "caked" at the bottom of the vial. Thus, when liquid is injected into the vial from a syringe the surface area of contact between the liquid and the Powdered drug may be quite small ini~ially, thus making the mixing Drocedure even more time consuming. Because of the limited vial volume, the increasing drug concentration in the diluent makes it harder to finish the reconstitution process. The oPerator may attemDt to solve this by repeatedly injecting solution into the vial, mixing and withdrawing the solution but this makes necessarY additional injections and movement of the syringe which increase the likelihood of contamination. Also, it is sometimes difficult to get all of the drug and/or liquid out of the vial, thus increasing the time required to Perform the reconstitution procedure, The reconstitution procedure should be Derformed under Preferably sterile conditions, In addition to such a requirement making the oPerator justifiablv more cautious and consuming more time, sterile conditions are often hard to maintain. In some instances, a laminar flow hood may be required under which the reconstitution Procedure is performed.
Snme drugs, such as some chemotheraDy drugs, are toxic.
ExPosure of the oDerator to the drugs during reconstitution may be ~2~77S~

dangerouS, esPecially if the ooerator works with such drugs on a daily basis and is repeated'ly exposed to them.
A further Droblem is that the reconstitution procedure Drovides a source of confusion as to which container contains which drug. The diluent container should he marked with the drug with which it has been injected and the name of the Datient to whom it should he delivered.
After a drug is reconstituted and withdrawn into a syringe barrel, the drug maY in some instances be injected immediatelY into the intravenous system of a Datient. More tvDically however, the reconstituted drug is injected from the syringe into a larger container of solution as discussed above, for connection to an intravenous administration set. This is because often the drug reconstituted in the syringe is still at a concentration so high as to cause local toxicity in the veins of a Datient near the injection site whene the need'le Dierces the skin. This maY create severe vein irritation which may be medically harmful. AdditionallY~ even though the Droper dose of medication is in the syringe, immediate injection into the Datient's blood stream maY create a condition of sYstemic toxicity wherein the level of drug concentration in the Datient's entire blood stream is dangerously high. Yet another reason for not making the injection from the syringe directly into the patient is that it creates an additiona'l injection site into the atient, whlch maY be Dainful for the patient and Drovides another oDportunity for infection.
For these reasons, the reconstitutea drug is more typically injected into a diluent container.
A patient may tyDically be administered a dextrose or saline solution from a large volume Darenteral container, for example, such as a one liter container, delivered through an administration set such as a CONTINU-FL0~ administration set sold ~y Baxter Healthcare CorDoration. If the reconstituted drug were ~Z9775:~

injected into the large volume Parenteral container, delivery of the drug would usually be made over too long a time Deriod. Often, these large volume fluids are delivered at very slow flow rates.
More tyPically~ the reconstituted drug is injected into a small volume Darenteral container, such as a fifty milli'liter container sold bv Baxter Healthcare CorPoration. This MINIBAG'~
container is hung at a higher elevation than the large volume parenteral container and is connected by a secondary administration set to an injection site on the primary administration set. Because it is maintained at a higher elevation, the reconstituted drug in the smal'l volume container is delivered, after which fluid from the large volume container begins to flow once more. By utilizing a small volume container connected to an administration set for delivery of the drug or other beneficial agent instead of a direct syringe injection, the drug is delivered over a Dreferred time period that tends to minimize negative side effects.
A closed reconstitution deliverv system is disclosed in U.S. Patent Nos. 4,410,321; 4,411,662; 4,432,755; and 4,458,733, all assigned to Baxter Travenol Laboratories Inc., the assignee of the present invention. As shown therein, a container includes a drug and a diluent in seDarate compartments which are reconstituted in a closed system before the drug is delivered to the Patient.
TYDically~ the container is connected to an administration set which is connected at its other end to the primarV administration set~
such as with the small vo'lume Darenteràl container describea above.
The container shown in these Patents solves many of the problems associated with syringe reconstitution. The Product does however necessitate a series of reconstitution steDs which must be Performed by the nurse or other oDerator prior to delivering the fluid from the container.
Delivery of a drug or other beneficial agent in a manner not requiring reconstitution stePs by an oPerator is shown in U-S-lZ~77S~

Patent Nos. 4,424,056; 4,432,756; 4,439,183; 4,474,574; 4.479.793;
4,479,794; 4,525,162, and 4,548,599 and Canadian Patent NoO
1,173,795, assigned to Alza CorDoration of Pa1O Alto, California.
As disclosed in those patents, a Darenteral delivery system is disclosed which has a formulation chamber therein for administering a beneficial agent such as a drug. The s,ystem is advantageous in that it Provides for reconstitution of the drug by fluid flowing from a large volume Darenteral container for example, through the administration set containing the formulation chamber with the drug therein. The svstem intends tc eliminate the need for the time consuming reconstitution Drocedure descrihed above and apDears to eliminate the Droblems associated with the reconstitution procedure.
Another passive reconstitution s,ystem is disclosed in EuroPean Patent APPlication No. 0059694 to Aktiebolaget Hassle of Sweden.
Still another device for delivering a drug "in-1ine", i.e., in the administration set, is disclosed in U.S. Patent No.4,534,757 assigned to Alza CorPoration. The device holds the drug and includes a section through which the liquid Passes in a direction substantiall,y oDposite to the general direction in which liquid flows to the patient.
Yet another sVstem which attemPts to provide for drug reconstitution in-line without manual reconstitution by a nurse or other oDerator is shown in U.S. Patent No. 4,465,471, assigned to Eli Lilly and Co. of IndianaPolis~ Indiana. That Patent discloses constructions for a recePtacle in the administratlon set itself. A
separate cartridge containing the drug to be reconstituted and delivered to the Patient is Dlugged into the recePtacle.
EuroPean Patent APplication Publication No. 0146310 to Eli Lill,Y and Co-, corresPonding to U-S- Patent No- 4,573,967, is 129775~

directed to a system for drug reconstitution including an intravenous administration se~ an~ a drug vial and utilizes the vial vacuum to reconstitute the drug.
U.S. Patent No. 4,534,758 to Akers et al. discloses a relatively comDlex drug delivery apparatus with various valves.
When liauid from a container is delivered to the drug vial, the vial is to be agitated for a time sufficient to suspend the Dreviously dry medicine.
U.S. Patent No. 4,581,014 to Millerd et al. assigned to Ivac CorDoration of San Diego, California discloses a selector valve for delivering a Dreviously reconstituted drug from a drug vial through an intravenous administration set to a patient.
All the Publications described above are directed to solutions to the time consuming reconstitution Drocedure and/or its associated Droblems, such as delivery of the solution to a Datient.
In most of the offered solutions, delivery of the drug is intended to be Passive~ i.e., once the drug is Dlaced into the administration set, manual reconstitution steDs are not required.
Israel U.S. Patent No. 4,589,867 discloses a delivery aDparatus including an integral diluent container and a mixing container with an uPward flow path.
Riddell U.S. Patent No. 4,623,334 discloses delivery of a drug from an add-on vial in an uPward flow Path when made part of a fluid conduit to a patient. Israel and Rlddell are prlnciDally directed to deliverlng llquld havlng a decreasing drug concentration over time, to a Datient.
Ogle U.S. Patent No. 3,941,171 is directed to a fluid transfer device including an adaDter for connecting a chamber having a Dierceable closure with another container. Air may exit the chamber at an elevation higher than the point at which liquid enters the chamber.
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lZ~37751 Still another common feature of many of the attempted solutions disclosed in these publications is that delivery of the drug is intended to be able to be made in a manner which is essentially independent of the fluid flow rate through the administration set and into the patient. Stated differently, some of the systems are designed to deliver a certain dosage of drug ln a preselected time period, within a broad range of fluid flow rates. Delivery of a drug independent of flow rate is desirable because it ensures that the necessary dosage will be delivered within a therapeutically acceptable time period, which may be typically about twenty to thirty minutes, although this time period may vary depending upon the drug and dosage.
By making delivery of the drug or other beneficial agent independent of the flow rate, the system ensures that the drug will not be delivered too quickly should the flow rate be set too high by the nurse or other operator, thereby preventing the problem of systemic toxicity discussed above.
Some of the documents, such as U.S. Patent Nos.
4,424,056; 4,479,793; and 4,479,794, are also directed to systems having a beneficial agent placed "in-line" in an administration set for mixing of the agent and delivery to a patient, wherein the delivery of the agent may be made in a given volume of fluid. Also, a valve controlling fluid flow may be manually operated to deliver the agent in a manner which can be made dependent upon fluid flow.
At least the automatic reconstitution type systems discussed above, (i.e., those not requiring a separate agitation or mixing step), suffer from the possibility of creating a concentration of beneficial agent in the fluid being delivered to the patient which is too high at low flow rates. This results in local toxicity to the patient near the point of introduction into the body. The problem is solved by the invention disclosed 1~

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in Canadian Patent 1,261,701, entitled "Drug Delivery Apparatus Preventing Local and Systemic Toxicity", Thomas E. Needham et al., assigned to the assignee of the present invention. Further solutions to the problems of passively mixing and delivering a beneficial agent to a patient are disclosed in U.S. Patent No.
4,874,366, issued October 17, 1989 entitled "Housing Enabling Passive Mixing of a Beneficial Agent with a Diluent", Brian Zdeb et al., also assigned to the assignee of the present invention. In that application there is disclosed certain housing constructions for delivering the beneficial agent to the patient.
Typically, the housing includes a receptacle which is placed in-line in a medical liquid administration set and a separate cartridge including the beneficial agent.
The cartridge i6 plugged into the receptacle when it is desired to deliver the beneficial agent to the patient.
Active reconstitution by a nurse or other operator is not required. Instead, once the cartridge is plugged into the receptacle, liquid flowing from the source of medical liquid through the administration set flows into the receptacle and the agent-containing cartridge, reconstituting the agent. The solution with agent therein flows out the receptacle, down the administration set to the patient's venous system.
Canadian Patent Application Serial Number 538,209 filed May 27, 1987 to Zdeb et al discloses a passive drug delivery system including a cartridge for introducing a beneficiai agent into the fluid conduit of an administration set. An adapter means is mounted about the cartridge chamber holding the agent, for mounting the cartridge upon a receptacle in the fluid conduit and further providing for selective fluid communication between the receptacle and the chamber.
The adapter means includes flow path means including chamber piercing means and receptacle piercing means.

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The application discloses two separate cannulas acting as the flow path means, which is important for creating the proper fluid path through the chamber to ensure proper mixing of the beneficial agent within the chamber. Liquid enters the chamber from the fluid ~onduit and moves downstream, back into the fluid conduit, to the patient.
In order to reduce cost to manufacture, simplify operation, and facilitate an easier and better connection between the cartridge and the receptacle, it would be desirable to eliminate one of the cannulas forming the flow path means between the beneficial agent and the fluid conduit. It would be desirable to accomplish these goals while retaining the beneficial flow path such as described in Canadian Patent Appli-cation 538,209. It would be desirable to meet these goals in a cartridge structure and also in an adapter structure for connecting the cartridge and the receptacle.
Furthermore, in order to prevent accidental,unintended activation of the cartridge and to avoid being stuck by the needle upon removal of the cartridge from the receptacle and to avoid exposure to small amounts of the beneficial agent, it would be desirable to have structure that would prevent unintentional unit activation and that would prevent exposure of the needle or other cannula to the nurse and other hospital personnel after adm:Lnistration oS the beneficial agent and removal of the cartr:Ldge from the fluid conduit and receptacle.
It would also be desirable to have a unique receptacle that would permit the use of a single cannula in the flow path means between the receptacle and the cartridge, in a manner permitting the diversion of all fluid flow from the conduit into the cartridge when the cartridge is plugged into the receptacle and further permitting the free flow of fluid through the receptacle within the fluid conduit when the cartridge is not in place.

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` 12~7751 SummarY of the Invention The Dresent invention Drovides an imProved drug delivery system including a cartridge for introducing a beneficial agent into a fluid conduit for deliverY of the agent to a patient and including structure which both prevents inadvertent activation of the cartridge before intended use and which protects hosDital personnel from an exDosed needle or other cannula subsequent to use. The cartridge of the invention includes a rigid hollow tube and an agent-containing chamber slidably mounted at least partially within thehollow tube. In the first, Dre-use position the chamber extends farther from the hollow tube than it does in a second Position. At least one cànnula is mounted to the hollow tube extending OPDOsite the chamber. A Drotective cover or caP is originally in a chamber protective Dosition wherein the caP is securely but re`leasably mounted to the hollow tube first end in order to cover the chamber and Drevent movement of the chamber from the first to the second uosition. In the chamber Drotective position the cover prevents engagement of the chamber with flow path means, such as the cannula that Di erces closure means to the chamber when the chamber is in the second Position.
After the agent has been delivered to the Patient~ the cartridge is removed from the fluid conduit. The protectiVe cover is then securely mounted about the second, oPposite end of the hollow tube, covering the cannula, thereby protecting the nurse from the exDosed cannula and any of the agent that might dri D out of the cannula.

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lla An aspect of this invention is as follows:
A cartridge for introducing a beneficial agent into a fluid conduit for delivery of the beneficial agent, said cartridge comprising:
(a) a rigid hollow tube;
(b) a chamber having a beneficial agent t~.erein, said chamber being mounted adjacent a first end of said hollow tube and being slidably mounted at least partially within said hollow tube from a first position to a second position, such that in said first position said chamber extends a greater distance from said hollow tube than in said second position;
(c) at least one cannula mounted within said hollow tube, extending at least in a direction opposite said chamber; and (d) a protective cover selectively movable between a chamber protective position wherein said cover is securely but releasably mounted to said tube adjacent said first end thereof to cover said chamber and prevent movement of said chamber from said first position to said second position, and a cannula protective position wherein said protective cover is securely mounted about the other end of said hollow tube, covering said cannula.

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DescriDtion of the Drawings Fig. 1 is a Derspective view of an adminstration set connected to an intravenous solution container and a Datient, and inc'luding a receDtacle for receiving the cartridge and adaDter;
Fig. 2 is a DersDective view of the cartridge including the adaDter, flow Dath means, and protective cover;
Fig. 3 is a longitudinal cross-sectional view of the cartridge of Fig. 2;
Fig. 4 is an enlarged fragmentary cross-sectional view of the adaPter and flow path means of the cartridge shown in Fig. 3;
Fig. 4A, when taken with Fig. 4, is a cross-sectional view of an adaDter for a ~eneficial agent cartridge;
Fig. 5 is a cross-sectional view taken at line 5-5 of Fig.
4;
Fig. 6 is a DersDective view of the cartridge of Fig. 2, after the chamber is engaged with the adaDter means to activate the cartridge;
Fig. 7 is an enlarged fragmentary cross sectiona'l view of the receptacle shown in Fig. 1;
Fig. 8 is a longitudinal, cross-sectional view of the cartridge of Fig. 6 mounted uDon the receDtacle of Fig. 7;
Fig. 9 is a Derspective view of the cartridge of Fig. 2, with the Drotective cover adapted for engagement about the cannu'la and cartridge;
Fig. lU is a persPective view as in Fig. 9, with the rotective cover having been mounted about the cartridge;
Fig. 11 is a fragmentary, cross-sectional view of an alternate embodiment of the cartridge disDosed uDon a modified 3o receDtacle;

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Fig. 12 is a fragmentarv cross-sectional view of a still further embodiment of the cartridge, disPosed uDon a receptacle; and Fig. 13 is a fragmentar.v, exPloded, perSDeCtiVe view of the shell shown in Fig. 12.

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Detailed Descri~tion of the Preferred Embodiments Referring to Fig. 1, there is illustrated an admini-stration set 420 for the delivery to a patient 426 of a medical liquid, stored within a medical liquid source such as large volume parenteral container 424. The administration set 420 includes a fluid conduit 428 made for example of flexible polyvinylchloride tubing. Upstream connection means such as a standard intravenous admini-stration set spike 430 is mounted at the upstream end of the fluid conduit 428. The spike is adapted for piercing the membrane of the container administration port 432.
The fluid conduit 428 includes downstream con-nection means such as a Luer taper 434 mounted at the downstream end of the fluid conduit 428. The Luer taper 434 may be connected in accordance with standard technique to a venous catheter 436.
The administration set 420 may further include a standard pierceable injection situs 438 for injecting a medical liquid by means of a needle through the 20 injection situs 438. The administration set 420 may further include flow rate control means such as a standard roller clamp 440 mounted about the flow conduit 428.
The administration set 420 further includes a unique receptacle 442 shown in greater detail in Figs. 7 & 8. The receptacle 442 is an lmprovement to the receptacle disclosed in U.S. Patent 4,874,366 and Canadian Patent Application 538,209, both assigned to the assignee of the present invention. The receptacle 442 is mounted along the fluid conduit and is adapted for receiving a separate cartridge 444 containing beneficial agent, illustrated in Figs. 2 through 6 and 8 through 10. When the cartridge is mounted upon the receptacle, virtually all liquid from the medical liquid source container 424 that flows through the fluid conduit 428 into ,","" ~

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the receptacle 442 a'lso flows through the cartridge 444 before Dassing downstream out of the receptacle to the patient.
Downstream of the receDtacle 442 is an air chamber 446, illustrated in Fig. 1. As will ~e exDlained in greater detail below, the air f'lask 446 permits automatic priming of the cartridge 444 uDon mounting of the cartridge on the receptac'le 442 of the administration set 420. The air flask 446 absorbs the air disposed within the cartridge 444 and prevents that air from Dassing downstream to the patient.
In the Dreferred embodiment, the receDtacle 442 and air f'lask 446 are manufactured as a unit. The ail flask 446 includes an inlet 448 integral with the recePtacle 442. The inlet Dortion 448 defines a droD former 460, as illustrated in Figs. 3 and 7. The receDtacle receives fluid from ucstream fl~id condu~it 428a. Liquid Dassing through both the receptacle 442 and air flask 446 exits the air flask outlet 450 and transfers to connected downstream fluid conduit 428b.
In the Dreferred embodiment, the air flask 446 includes an outlet caP 454. A cylindrical side walt 456 of preferab'ly oPtically transParent~ flexible material such as polyvinylch'loride~ is mounted between the flask inlet Dortion 448 and the outlet caP 454. The side wall 456, the flask inlet portion 448 and the outlet cap 454 together define an air chamber 458 having a cross-sect~onal diameter that is greater than the internal diameter of the fluid conduit 428. Thus, liquid entering the air chamber 458 from the droD-forming orifice 460 adjacent the in'let 448 falls toward the outlet 450. The air flask 446 Drovides a collection reservoir for air within the administration set 420.
The air flask 446 further includes Darticulate matter barrier means such as a Darticulate matter screen 462 mounted near the outlet 450. The Darticulate matter barrier maY in fact be a sterilizing filter having a nominal pore size of about 0.2 micron.
The nomina'l Dore size may be much larger, such as a gross 12~77S~

particulate matter barrier having a nominal pore size of about 20 microns. In the preferred embodiment the nominal pore size is about 10 microns. The screen may be a Dolvester or nylon mesh material such as SupDlied by Tetko of Switzerland. The Particulate matter barrier 462 iS mounted transverse to the fluid Dath such that all liquid Dassing through the air flask 446 must pass through the Darticulate matter barrier 462 before ~eing delivered to the patient.
The Darticulate matter barrier 462 need not be disposed within the air flask 446 but the barrier should be mounted downstream of the receDtaCie 442 SO that all liquid that exits the inserted cartridge 444 will Dass through the Darticulate matter barrier.
In the preferred embodiment, the air flask 446 includes a minimum liquid level indicator 466 and a maximum liquid level indicator 468 which ma,y for examDle comDrise lines around the periphery of the air flask 446. The liquid level in the air flask 446 should preferabl,v be somewhere between the minimum and maximum liquid level indicators 466, 468 immediately before insertion of the cartridge 444 within the receDtacle 442.
As illustrated in Figs. 7 and 8, the imDroved receptacle 442 includes a receDtacle inlet 470 connected to the fluid con~uit 428 and an outlet formed by the flask inlet Dortion 448. The air f'lask 446 iS
disDosed downstream of the receptacle outlet 472. The receDtacle inlet 470 and the air flask nutlet 450 ma,y be mounted to the fluid conduit 428 b,Y means of interference fit, solvent bonding etc.
The recePtacle 442 includes upper and lower fitments 474, 476 respectivel,y. The upper fitment 474 includes the inlet. The lower fitment 476 includes the outlet 472. A Diercable, resilient injection site 480 is mnunted within the upDer fitment 474 of the receDtacle 442, such as by ultrasonicall,y swaging a mount 475 for the injection site 480. The uDDer and lower fitments 474, 476 may be bonded together bv adhesive, ultrasonic sealing etc. It is imDOrtant that the injection site be securely maintained within the receDtacle ~Z~775~

because a Dlurality of cartridges 444, each having a cannula, maY be mountea on and removed from the injection site during the useful life of the receDtacle 442 and administration set 420.
The receDtacle 442 includes a resilient divider 492 traDPed t\etween the uDDer and lower fitments 474, 476 of the receptacle 442.
The resilient divider defines a narrow through bore 494 directly below the resilient Piercable injection site 480~ As will be seen below, only that Dortion of the divider 492 that defines the through bore 494 utilizes resiliency as a desirable quality; however, for ease of manufacture, it is simDle to define the through hore 494 with the divider 492, the divider 492 defining the flow Path through the receDtacle 442.
Before the cartridge of the Dresent invention is engaged with the receDtacle 442, fluid flowing from the Darenteral container 424 lS flows through the fluid conduit 428 and through the receptacle inlet 470, whereuDon it flows into the receDtacle above the divider Dlate 492, through the through-bore 494 and downstream to the receptacle outlet 472 and downstream through the air flask 446 to the Datient.
Turning now to Figs. 2 through 6 and 8 through 10 there is 2n shown the cartridge 444 and an adaDter 477 for introducing a druy or other ~eneficial agent into the fluid conduit 28 at the receDtacle 42, for delivery of the agent to a patient.
The cartridge 444 may include the adaDter 477. Alternately, the adapter 477 maY be a seDarate unit 477' suitable for connecting a beneficial agent chamber 606 with the receDtacle 442.
Referring to Figs, 2, 3, 4 and 5, and esDeciall~y to Fig. 4, the cartridge 444 includes an adaDter 477 having a rigid hollow cylinder ' or tube means 496 and a kevway wall 618, with the keyway wall 618 being Dart of the tube 496. A Dlate 498 is mounted across the tube 496 and defines the starting Point for the keyway wall 618.
A rigid cannula 500 extends through the Plate 498. A generally cylindrical shell 502 extends from both sides of the Dlate 498. The lZ~
lg hollow tube 496, the plate 498 and the shell 502 may all be formed as a single piece of the same material such as a plastic.
The shell 502 is spaced from the cannula 500, with the shell 502 encompassing the cannula 500 but being shorter than either end of the cannula 500. The cannula 500 includes an inlet 504 and an outlet 506. In the pre-ferred embodiment the inlet and outlet 504, 506 respectively are pointed to facilitate piercing. The cannula 500 is preferably but not necessarily made from a single piece.
The shell 502 is intermediate the cannula inlet and outlet 504, 506. The cannula 500 and the shell 502 define a channel 508 therebetween. In the preferred embodiment the periphery of the cannula 500 is circular along its length.
15 Similarly, the internal surface 522 of the shell 502 is preferably arcuate and preferably circular along its le~gth.
The channel 508 includes a channel inlet 510 defined between the shell 502 and the cannula 500, short of the cannula outlet 506. Similarly, the channel 20 includes a channel outlet 512 defined by the shell 502 and the cannula 500, short of the cannula inlet 504.
A preferably plastic cannula holder 514 is secured to the cannula 500. The cannula holder 514 grips the cannula 500. Aa seen best in Figs. 4 and 5, extension 25 means 516 extend between the cannula holder 514 and the shell 502, across the channel 508, thereby securing the cannula 500 relative to the shell 502. In the preferred embodiment the extension means 516 is part of the holder 514.
The structure of the shell 502 surrounding the 30 cannula 500 forms a channel of about 360. Thus, the exterior portion 514a of the cannula holder 514 may be disposed fairly close to the channel outlet 504, the opening having a vertical height of only about 0.005 to 0.010 inch in the preferred embodiment. This is a much smaller dimension than presented when a separate cannula is used for the fluid flow into the cartridge chamber, such as shown in Canadian Patent Application Serial No. 538,209.

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Wit~ this small size opening presented to the cartridge chamber, powdered beneficial agent within the chamber is prevented from exiting through the channel outlet 504 when the cartridge i activated.
As seen best in Fi~. 4, in the preferred embodiment a portion of the cannula holder is disposed at least part-ially outside said shell 502 and includes a tapered portion or portions 518 to facilitate insertion through an injection site. Also, in the preferred embodiment this exterior portion 514a of the cannula holder 514 is mounted adjacent the channel outlet 512, short of the cannula inlet 504.
In the preferred embodiment at least a portion 514b of the holder 514 is disposed inside the shell 502.
That portion 514b has a preferably substantially polyganol, preferably square cross-section which serves as the extension means 516. The corners 520 of the cannula holder portion 514b/extension means 516 fixedly engage the interior surface 522 of the shell, preferably by means of a secure friction fit.
Thus, with the described structure for the adapter 477, the cannula 500 is secured to the shell 502 while still maintaining an open flow path through the channel inlet 510, the channel 508 and the channel outlet 512.
This is accomplished without complicated and expensive molds and molding techniques and without the use of any ultrasonic bond or adhesive or solvent to bond the cannula to the shell. Thus, a very small flow path is created outside a single cannula, with precision. It is desirable to exclude adhesives and/or solvents from contact with medical solutions and this is accomplished with the adapter of the present invention. Additionally, such substances, as well as ultrasonic welding, might tend to clog the small channel 508.
Referring to Figs. 2 ~ 3, the cartridge 444 further includes a tubular chamber 606 containing a beneficial agent 608 such as a dry 775~

powdered drug, although the agent may also be a liquid. A Dierceable stopper 604 or other closure means closes the tubular chamber 606.
Referring to Figs. 3 and 4, the shell 502, along with the - channel outlet 512 and the cannula inlet 504, are designed to Pierce tho Dierceable stopPer 604 or other injection site/closure means to the chamber 606 having the beneficial ayent 608 therein. Similarly, the shell 502, along with the defined channel inlet 510, together with the cannula outlet 506, are designed to Pierce the injection site 480 in the receDtacle 442.
Fig. 4, as mentioned Dreviously, is a fragmentary en'larged cross-sectional view of the adaPter portion 477 of the cartridge 444 illustrated in Fig. 3. However, as stated above, the adapter 477 may be a seDarate unit adaPter 477', i'llustrated by taking Fig. 4A in combination with Fig. 4, The first end 524 of the hollow tube 496 in adapter 477' maY simDly terminate such as in a plane PerDendicular to the length of the tube 496 and preferably beyond the in'let end 504 of the cannula 500, as illustrated in Fig. 4A.
Referring once more to Figure 3, the Pierceable stoPPer 604 is mounted within the mouth 610 of the tubular chamber 606. The rubber stoPDer 604 maY ~e secured within the tuDular chamber 606 by means of a metal band 612 about the Deripherv of the mouth 610 and the ru~Der stoDDer 604, in the known manner for securing of a stoPper in a standard drug vial. The chamher 606 ma~y be a stan~ard drug vial, dePending on the required chamber d1mensions, discussed below. The tubular chamber 606 is slidably mounted within the rigid cYlinder 496 such that the rubber stoDPer 604 faces the Dlate 498. In Place of the Dierceable stoDPer~ other Pierceable closure means may be Drovided.
When the cartridge chamber 606 is in a first Position illustrated in Figs. 2 and 3, the rubber stoPper 604 has not been Pierced through by either the shel'l 502 or the cannula inlet 504. In the Dreferred em~odiment, the Pierceable stoDPer 604 remains sDaced from the cannula 500 when the tubular cartridge 606 is in the first position.

12~7~5~

The cannula 500 and the shell 502 comprise flow path means, which is Dart of the adapter means, which itself may be part of the cartridge 444. As seen in Fig. 2 and esDecially in Fig. 3, the hollow tube 496 is mounted about the chamber 606 and the adaDter 477 facilitates mounting the cartridge 444 uDon the receptacle 442. The adaDter 477 slides re'lative to chamber 606. Stated differentl,y, the tubu'lar chamber 606 and the adapter 477 are selectively slidable re'lative to each other.
The adaDter means Dreferably includes the keyway means extending on the side of the base Dlate oDDosite of the chamDer 606 and substantiall,Y coaxial therewlth, and formihg Dart of the tuhe means 496. The ke,ywa,y means may include a relativelY rigid keyway wall 618 having a keywaY slot 620 for fitting over the receptac'le 442. The keywa,Y means ensures Dro~er engagè,nent of,,the cartridge 444 with the associated receDtacle 442, including the DroDer dispnsition of the cannula outlet 506,shell 502 and channel inlet 510 within the receDtacle 442, as seen in Fig. 8.
Referring to Figs. 2 & 3, the cartridge 444 also includes a cartridge-removable cannula cover 601 removably secured within the base Dlate 498. The cartridge-remova~le cannula cover 601 has as its Drincipal Durpose Dreventing the connection of the cartridge 444 to the receptacle 442 without first Diercing the stoPDer 604 with the , cannula 500 and shell 502. The cannula cover 6~1 ensures that the chamber 606 must be moved from the first Dosition illustrated in Figs.

2 and 3 to the second Dosition illustrated in Figs. 6 and 8 nefore the cartridge 444 can be mounted uDon the receptacle 442. Should the cartridge be mounted prematurel,y, i.e., before the cartridge is moved to the second Dosition, liquid flowing through the administration set would sDill out of the shell 502 at the channel outlet 512 without entering the cartridge cham~er 606.
Because of the relativel,y small dimensions of the keyway wall 618, the cannula cover 601 cannot be removed from the cartridge 444 when the cannula cover 601 is disDosed as shown in Figs. 2 and 3.

lZ9775~

The cannula cover 601 includes DinS 603, including a reduced pin Dortion 605 at the dista~l end of each pin and an enlarged Pin Dortion 542 at the Droximal end of each pin. The Dins extend from a circular cannula cover base 60g. The cannula cover base 609 fits snugly but not tightl,v against the ke,ywa,y wall 618. ODenings 611 extend through the ~late 498 and receive the enlarged pin Dortions 542 of the Pins 603, preferably in interference fit so that the cannula cover 601 will not inadvertently become detached from the Dlate 498.
The chamber 606 of the cartridge 444 is slidahle from the first Position shown in Figs. 2 and 3 to a second position illustrated in Figs. 6 and 8 ~v pushing the chamber 606 down within the rigid c,ylinder 496 until the Pierceable stoPper 6n4 or the metal band 612 thereahout abuts the Plate 498, which serves as a stop. In this second Dosition, the cannula inlet 504, the cannula holder 514, the shell 502 and the defined channel outlet 512 have Pierced the stoPPer 604 or other second resilient injection site. Thus, within the chamber interior, the channel outlet 512 and the cannula inlet 504 are in fluid communication. The cannula inlet 504 is well within the tubular chamber, preferably near the toP ena 626 of the chamber 606.
This is best illustrated in Fig. 8, wherein it is also shown that the defined channel outlet 512 is preferahl,y just within the tubular chamber 606. This second position is also illustrated in Fig. 6.
Because the shell that forms the channe'l outlet 512 and the base Dlate 498 acting as the stoD are Dreferabl,y molded from a single Piece~ it is eas,Y to consistentl,Y manufacture a cartridge 444 with a fixed distance between the channel outlet 512 and the stoPDer 604. It is imDortant to control this distance when Planning for the mixing action within the chamber.
The cartridge 444 also includes a Drotective caP or cover 530 initiall,v disPosed in a chamber Drotective Dosition covering the chamber 606, as seen for examDle in Figs. 2 and 3. In the Dreferred embodiment the Protective cover 530 includes a toP 532 and a skirt lZ~77~

534 deDending from the toD 532. The free end portion 536 of the skirt 534 fits snugly about the first end 497 of the hollow tube 496. In the Dreferred embo~iment, ~oth the first end 497 of the tube 496 and the free end Portion 536 of the protective caD 530 are enlarged so as to fit about the structural su~port 538 of the hollow tuhe 496, Drovided so as to securely retain the cham~er 606 a~out the mouth 610 thereof.
In operation~ before a beneficial agent 608 in the cartridge is delivered to the patient, the administration set 420 of the invention operates by Droviding an oPen fluid Dathway between the medical liquid container 424 and the patient 426, as illustrated in Fig. 1. Li~uid 422 flows from the container 424 through the administration port 432 and sDike 430. The liauid flows through the fluid conduit 428 and through the recePtacle 442, following the Pathwav through the receptacle inlet 470, through-bore 494 and outlet 472, in that order.
Liquid flows into the air flask 446 through the drop former 460. Any air from uPstream col'lects within the air flask 446 and liqui~
continues to flow downstream through the flask outlet 450 through the downstream conduit portion 428b and into the Patient through the Luer connection 434 and venous catheter 436.
Before the administration set 420 is Placed in communication with the patient 426, the fluid conduit 428 is Drimed, i.e., air is eliminated. l'his is Performed in the known manner, bY allowing liquid to flow through the set 420 ~efore connection to the Patient, To raise the liauid level up to a leve'l 62~ within the f'lask 446 such that it is between the minimum and maximum indicator lines 466, 468, the air flask sidewall 456 may be squeezed and released such as with most driP chambers, in the standard manner.
When it is desired to deliver a beneficial agent 608 such as a drug to the Datient, the cartridge 444 having the beneficia'l agent 6n8 therein is mounted uPon the receptacle 442 as shown in Fig. 8.
The cartridge is provided to the nurse or other medica'l Personnel as illustrated in Figs, 2 and 3, with the chamber 606 in the 12977~

first Dosition. The urotective caD 530 Drevents anY urging of the chamber 606 so as to Drevent its engagement with the cannula 500 and the shell 502. The cover 530 may also assist in retaining the chamber 606 within the tube 496 when the chamber 606 is in the first Dosition.
A shrink wraD band 534 may he disposed about the free end portion 536 of the caP 530 and about the first end 497 of the hollow tu~e 496.
Together with the snug friction fit of the free end Dortion 536, the shrink wraD Drevents accidental remnval of the protective cover 530.
TyPically~ the cartridge 444 will be packaged in another, sterile container to assure the sterility of the cartridge interior, inc'luding the cannula 500, the shell 502, and the pierceab'le stopDer 604. However, it is possible that the protective cover 530, the hol'low tube 496 and the removable need'le cover 601 may maintain the exDosed Dortion of the Pierceable stopDer 604 and the cannula 500 and shell 502 in aseDtic condition.
To activate the cartridge, the shrink wraD band 534 is torn awav. The nurse removes the protective cover 530 from the remainder of the cartridge. The oDerator then grasDs the rigid tube 496 and Dushes down on the toP 626 of the chamber 606 with the thumb, thereby slidaDly moving the cartridge chamber 606 within the hollow tube 496,1n this one action, first the cannula inlet 504 and then the shell 502 Dierce the pierceable stoDper 604. In the preferred construction illustrated in the drawings, after the cannula inlet 504 pierces the stopDer, the cannula holder 514 Dierces the stoPPer~ followed bV the shel'l 502, with the shell 502 and the cannula holder 514 defining the channel outlet 512, which is now diSDosed slight'ly within the chamber 606. In the same motion, the chamber 606 continues to he urged into the hollow tube 496 until it engages the pins 603 of the cannula cover 6n1, forcing the enlarged Pin portions 542 out of the openings 611 in the Dlate 498. When the chamber fiO6 comes to the stoD adjacent the Dlate 498, only the reduced Pin portions 605 remain within the oDening 611, so that the oDerator may easily grasD the cannula cover 601, now ~2~3775~L

projecting past the end of the keyway wall 618. Alter-natively, since the narrower pin portions 605 are now within the openings 611, there is no longer an inter-ference fit between the plate 498 and the cannula cover 601, so that the cannula cover 601 will now preferably simply fall out of the cartridge 444.
lt should be noted that in addition to preventing improper mounting of the cartridge 444 upon the recep-tacle 442 as explained above, the needle cover 601 also prevents touch contamination of the cannula 500 until activation of the cartridge 444.
With the cartridge chamber 606 now in the second position, the cartridge 444 is mounted upon the receptacle 442 as illustrated in Fig. 8 by grasping the receptacle 442 in one hand and the rigid cylinder 496 in the other hand and pushing the cartridge down so that the cannula outlet 506 and then the shell 502 with defined channel inlet 510 both pierce the first resilient injection site 480, which in the pre-ferred embodiment is the injection site on the receptacle.
The cartridge 444 continues to be urged downwardly so that the cannula outlet 506 enters the through-bore 494 and is liquid-sealingly engaged by the resilient divider 492 around the periphery of the cannula outlet portion 506. Unlike the cartridge disclosed in Canadian Patent Application Serial No.
25 538,209 to Zdeb et al having two separate cannulas, the rotational positioning of the cartridge 444 relative to the receptacle 442 is not critical with the device of the present invention. However, the vertical positioning of the cannula outlet 506 and the shell 502 with defined channel inlet 510, relative to the receptacle, is important. This proper vertical positioning of the cartridge 444 relative to the receptacle 442 is assured by the keyway wall 618 and keyway slot 620. The keyway slot 620 is guided over the bridge 630 of the upper fitment 474 on the receptacle 442. Downward movement of the cartridge upon the receptacle is limited by the slot top 621 abutting the bridge 630 of the receptacle.
Further downward movement of the cartridge is not possible and thus proper vertical lBI

`` 1;~77~i~

positioning of the cannula outlet 5n6 and the channel inlet 510 within the receDtacle is assured.
proDer installation has occurred when as noted the slot toP 421 abuts the bridge 630. Alternatively, other stops could of course be imDlemented, such as the Dlate 498 abutting the injection site 480.
After the cartridge is thus mounted about the recePtacle~ the nurse or other operator maY either Place the Protective cover 530 in a Docket or ma,v remount the protective cover ahout the first end 497 of the hollow tube 496.
uPon engagement of the cartridge 444 and receDtacle 442 as il'lustrated in Fig. 8, liquid 422 flowing into the receDtacle at the inlet 470 is Drevented from passing through the through-bore 494 and out the receptac'le 442 because the resilient divider 492 has been sealed about the cannu'la outlet Dortion 506 at the through-bore 494.
Thus, liauid entering the receDtacle 442 enters the channel inlet 510, flows through the channel 508 and enters the tubular cham~er 506 at the channel outlet 512.
As liquid rises within the chamher 606, residual air within the chamber is forced downstream through the cannula inlet 5~4 and then the cannula outlet 506. The air enters the air f'lask 446 through the droP former 460 and col'lects within the flask 446. The initial 'liquid level 628 illustrated in Fig. 1 droPs to a new level. The liquid level 628 should be above the minimum liquid level indicator 'line before inSertion of the cartridge 444 into the administration set 420 so that as air exits the cartridge 444, the liquid level within the air flask 446 will not drop to the flask out'let 450 where it coul~ be - trapDed and forced downstream to the Datient. The liquid level after cartridge Driming may be below the minimum liquid leve'l 466, but if it is above the minimum line 466 before insertion of the cartridge 444, the liauid level will never ~e as low as the outlet 450.
The maximum liquid level indicator 468 serves as a guide for the maximum liquid level so that liquid drops entering the air flask ~2V~7751 through the drop former 460 may still be cnunted in the manner of a standard driP chamber.
The liauid level within the tubular chamber 606 continues to rise until it reaches the cannula inlet 504, whereuDon liquid begins to exit the chamber 606 through the cannula 500, downstream through the cannula outlet 506 and into the air flask 446 through the droP
former 460. Liquid exiting the chamber 606 has an aDDroDriate concentration of beneficial agent 608 mixed therewith for deliver,y to the Datient. The upward liquid flow Dath created within the chamber 606 by the shell 502, channel 508 and cannula 500 creates a density gradient within the chamber 606 such that the concentration of drug within the liquid 422 exiting at cannula outlet 5U6 will not be so high as to create local toxicity to the patient. Loca'l toxicit~v is a situation in which vein irritation can occur near t~ venous injection site when drug concentrations within the delivery liquid 422 are too high.
If a seParate ada~ter 477', as illustrated in the combined Fig.
4, Fig. 4A is utilized instead of the adaDter 477 which is Dart of the cartridge 444, a chamher 606 is inserted into the hollow tube 496 at the toP end 524 thereof, thereby installing the chamber 606 within the adaDter 477' as described with the cartridge 444 and adaDter 477 above. The chamber 606 is urged tnward the Dlate 498 until the cannula inlet 504 and then the coaxial shell with the channel outlet 512 Pierce the stoPper 604 and the chamber hits the Plate 498 or other stoD. The adaPter 477', with the chamber 606 mounted therein, is mounted about the receDtacle 442 in the same manner as described above relative to the cartridge 444 with adapter 477. The fluid flow Dath through the f'luid conduit 428, the receptacle 442, the chamber 606 and adaDter 477' is the same as described above relative to the cartridge 444 and receptac'le 442. The separate unit adaPter 477' may he packaged in a sterile wrap or package.

12~775~ `

At tyPical liquid flow rates, the amount of drug delivered to the Datient per unit time is generally independent of the flow rate.
This means that at extremely hign f'low rates, the total amount of drug delivered to the Datient Der unit time will not be so high as to cause systemic toxicity to the patient. Stated differently, the patient will not have too much drug introduced into the body in too short a time Deriod.
It is believed that at lnwer liquid flow rates the rate of drug delivered to the Datient Der unit time tends to become ~ore dependent uDon the liquid flow rate through the administration set 420.
However, local toxicity to the patient wil'l not occur. It is believed that the uPper limit on the drug concentration within liquid 422 exiting the cham~er 606 is 'limited to a safe maximum for two princiDle reasons. First, the density gradient created within the columnar tubular chamber 606 means that the concentration of liquid 422 at the point of entry into the cannula inlet 504 is the lowest of any elevation within the tubular chamber 606. Secondly, as the liquid flow rate through the administration set 420 decreases, which would ordinarily increase the risk of an unaccePtably high drug concentration to the Datient, the amount of mixing and liquid turbulance created within the chamber 606 also decreases, exaggerating the density gradient so that the difference in densities from the area of the stoDPer 604 to the cannula inlet 504 becomes greater.
It is to be noted that the different liquid flow rates mentioned above are only Dossihilities; in the preferred manner of oDeration, the nurse or other medical Personnel would set an acceDtable flow rate with the flow rate control means (such as the roller clamP 440 or a Deristaltic pumD) and not adjust the liquid flow rate again, at 'least unti'l after delivery of the beneficial agent 608.
The administration set 420, with the unique cartridge 444 and receDtacle 442, are caDable of delivering a therapeutically beneficia amount of a beneficial agent 608 within a theraPeutically accePtable `"` ~2.97~

time Deriod~ For examD'Ie, a one gram dose of amDicillin in the chamber 606 maV ~e delivered in a~out thirty minutes at a liquid flow rate of 120 mls Per hour, In the preferred embodiment, the tuhular cham~er 606 has a volume of about 10 mls, and may include uP to about 3 to 4 mls of air. The internal diameter of the ~ubular chamber is about 0.4 inch.
The height of the tubular chamher from the mouth 610 to the top 526 is about two inches. The relativelv long, narrow cnnfiguration of the chamber 606 is also believed to assist in mixing the beneficial agent 608 with the liquid 422. The liquid 422 may be a 5% dextrose solution for examPle.
~ y varYing the dimensions of the tuhular cham~er 606 the delivery Profile for the Deneficial agent 608 may be changed. For examPle~ ~y en'larging the internal diameter of the tuDular cham~er, it will take longer to deliver the agent 608 within the chamber 606 to the patient 26. Simi'larly, lengthening the chamber 606 wil'l also increase the delivery time if the cannula 500 is also extended within the longer chamDer.
As noted Dreviously, more than one cartridge 444 maV be utilized during the use o~ a single administration set 420. If so, the cartridge 444 must De removed from the recePtacle 442 and disPosed of so that another cartridge 444 may he installed uPon the receDtacle 442.
As the cartridge 444 is pulled off the receptacle, the through-hore 494 is once more opened so that the fluid flow Path will resume as described earlier, before insertion of the first cartridge. As the shell 502 and cannula 50U are withdrawn~ the resilient injection site 480 will reseal. Now, to avoid driPping of anV Iiquid out of the tubular chamber 606 and to Drevent any Dossibility of personnel being stuck by the cannu'la outlet 506, the Protective cover 530 is installed over the tu~e 496 and cannula outlet 506 such as illustrated in Figs.
9 and 10. In this cannula Drotective Position, the used cartridge 444 has no exposed cannula point. Any liquid dripping out of the chamber 606 will simply collect harmlessly within the protective cap 530, which engages the cartridge 444 by friction fit about the outside of the tube 496.
Referring now to Fiq. 11, there is disclosed a cartridge 644 and a receptacle 642 according to another embodiment of the invention. In this embodiment the shell 646 is identical to the shell 502 on that side of the plate 499 that defines the channel outlet 512.
However, the shell 646 extends further toward the cannula outlet 506 so that it is the shell portion 648 adjacent the cannula outlet 506, instead of the cannula outlet portion 506 itself, that is liquid-sealingly engaged about the exterior thereof when the cartridge 15 644 is mounted on the receptacle 642. Although a receptacle such as receptacle 442 with the resilient divider 492 could be utilized, here the receptacle 642 includes a resilient bushing 650 similar to the receptacle illustrated in Canadian Patent Application 20 Serial No. 538,209 to Zdeb et al. ~he receptacle 642 includes upper and lower fitments 65~, 654 respectively.
The resilient bushing 650 is mounted within the lower fitment 654, directly below the injection site 480 and includes a through-bore 656 larger than the through-bore 25 494 of the resilient divider 492 so as to permit the shell portion 648 to enter the through-bore 656 for liquid-sealing engagement between the bushing 650 and the shell portion 648.
In this embodiment, the defined channel inlet 658 30 i8 disposed within the sidewall 660 of the shell 646, 648, spaced sufficiently above the cannula outlet 506 so that it is above the bushing 650 and not encompassed by the bushing 650, thereby permitting fluid flow into the channel inlet 658 from the receptacle inlet 662.
The lower fitment 654 of the receptacle 642 may include a tapered introducer portion 664 to ensure proper introduction of the cannula outlet 506 and shell portion 648 within the resilient pushing 650.

LB. ~
t :IL2~

Thus, with the cartridge 644 and recePtacle 642 illustrated in Fig. 11, liquid flowing into the receDtacle through the inlet 662 flows into the channel inlet 658, upwardly through the defined cnannel 508 and out the defined channel outlet 512 into the chamber 606 having a heneficial agent 608 thereinO Liquid flows uDwardly in the chamher to the cannula inlet 504, whereupon it flows down out the cannula outlet 506, through the droD former 460 and downstream to the Patient.
Referring now to Figs. 12 and 13, there is shown yet another embodiment of the invention. A cartridge 744 is similar to the cartridge 644 and may be emPloyed with the recePtacle 642 of Fig. 11.
Here, the shell portion 648', that engages the bushing 650 in the same manner as the ~ushing 648, is a seParate part frorn the remainder of the shell 646 and includes at least one and Preferably a DluralitY of channel inlets 746 defined by Dosts 748 that extend from the seDarate shell portion 648' and which abut the remainder of the shell 646.
Fig. 13 illustrates the shell 646 before installation with the cannula 500. The flow path of fluid through the receDtacle and the cartridge 744 is the same as described relative to Fig. 11.
2U The emhodiments of the cartridge illustrated in Figs. 11-13 will also work with the recePtacle illustrated in Fig. 7.
While several embodiments and features have been described in detail herein and shown in the accomPan~Ying drawings, lt will be evident that various further modifications are Possible without deParting from the scoPe of the claimed invention.

Claims (3)

1. Claim 1. A cartridge for introducing a beneficial agent into a fluid conduit for delivery of the beneficial agent, said cartridge comprising;
   (a) a rigid hollow tube;
   (b) a chamber having a beneficial agent therein, said chamber being mounted adjacent a first end of said hollow tube and being slidably mounted at least partially within said hollow tube from a first position to a second position, such that in said first position said chamber extends a greater distance from said hollow tube than in said second position;
   (c) at least one cannula mounted within said hollow tube, extending at least in a direction opposite said chamber; and (d) a protective cover selectively movable between a chamber protective position wherein said cover is securely but releasably mounted to said tube adjacent said first end thereof to cover said chamber and prevent movement of said chamber from said first position to said second position, and a cannula protective position wherein said protective cover is securely mounted about the other end of said hollow tube, covering said cannula,
2. Claim 2. The cartridge as in Claim 1, further wherein said protective cover comprises a top, a skirt portion depending from said top and an enlarged open end portion for engaging said hollow tune.
3. Claim 3. The cartridge as in Claim 1, wherein said protective cover is generally cup shaped.