Intradermal pen adapter

An intradermal injection adapter includes a body having a longitudinal axis and a central portion located distally relative to the body along the longitudinal axis. The central portion has a cannula channel therethrough extending generally parallel to the longitudinal axis. A cannula within the cannula channel has a sharpened tip for injection into a patient and a sharpened opposite proximal end for injection into a pen injector. A distal protrusion has a first skin contacting surface extending generally parallel to the longitudinal axis. The first skin contacting surface is spaced from the cannula such that a distal portion of the cannula extends generally parallel to the first skin contacting surface.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a Non-Provisional of Provisional Application No. 61/461,650, entitled “Intradermal Pen Adapter”, filed Jan. 21, 2011, the contents of which are incorporated herein by reference in their entirety.

BACKGROUND OF THE INVENTION

Intradermal injections are used for delivering a variety of diagnostic and treatment compositions into a patient. Intradermal injections are typically injections of a relatively small amount of medicament into the dermis or dermal layer or even into a lower portion of the epidermis (FIG. 2A) of a patient's skin. Substances may be injected intradermally for diagnostic testing, such as to determine a patient's immunity status against tuberculosis and the status of allergic diseases. Vaccines, drugs and other compounds may also be delivered intradermally. In many instances, intradermal delivery is preferred because it generally requires a smaller volume dose of the diagnostic or treatment compound than other delivery techniques. There is considerable variation in the thickness of a patient's skin, both between individuals and within the same individual at different sites of the body. Generally the outer skin layer, or the epidermis, typically has a thickness between two hundred and five hundred microns (200-500 μm) and the dermis, the inner and thicker layer of the skin, generally has a thickness between one and one-half to three and one-half millimeters (1.5-3.5 mm).

Making intradermal injections is difficult and generally requires an experienced nurse or medical professional. Incorrect placement of the tip of the cannula may lead to a failed injection. The placement of the cannula tip deeper than about three millimeters (3.0 mm) has the potential of delivering the injection into the subcutaneous region, where the intradermal dosage may be insufficient. Incorrect placement of the cannula may also puncture the skin again after being inserted into dermis, with the delivered compound being lost on the surface of the skin. Injection is often followed by a jet effect, with the compound exiting the injection site through the puncture track. The jet effect is even more pronounced for injections through a cannula placed perpendicular to the injection site and in particular for shallow delivery. The success of intradermal injections is often determined by the skill and experience of the individual healthcare professional administering the injection. The preferred intradermal injection technique (using a standard cannula), requires the healthcare professional to stretch the skin, orient the cannula bevel to face upward, and insert a short bevel cannula at an angle of around ten to fifteen degrees (10-15°) relative to a surface of the skin, while also assuring that two to three millimeters (2-3 mm) of the cannula are located in the skin. The cannula tip ideally ends up positioned in the dermis or close to the dermis/epidermis boundary. The compound is slowly injected into the skin of the patient, forming a blister or wheal. The insertion of the cannula at an incorrect angle and/or depth results in a failed intradermal injection, which is typically repeated, causing additional pain and discomfort as well as ineffective treatment to the patient. Intradermal (ID) injection has been considered for immunization in the past, but has generally been rejected in favor of more reliable intramuscular or subcutaneous routes of administration because of the difficulty in making a successful ID injections, particularly when the injections are administered by relatively unskilled healthcare professionals.

Administration into the region of the intradermal space has been routinely used in the Mantoux tuberculin test, in which a purified protein derivative is injected at a shallow angle to the skin surface using a twenty-seven (27) or thirty (30) gauge cannula and a standard syringe. The technique is known to be quite difficult to perform and generally requires specialized training. A degree of imprecision in the placement of the injection results in a significant number of false negative test results. As a result, the Mantoux approach has not led to the use of intradermal injection for systemic administration of substances, despite the advantage of requiring smaller doses of substances, because the absorption of the medicament into the dermal skin layer is typically superior to injection of the same substance using alternative techniques.

It would be desirable to design and manufacture an intradermal injection adapter that provides a relatively simple, reliable intradermal injection, is relatively easy to use, is relatively cost effective to the user and limits waste of medicament. The cannula of the intradermal injection adapter is preferably statically mounted to or fixed relative to a body of the adapter and/or a barrel of a syringe or pen in an assembled configuration.

BRIEF SUMMARY OF THE INVENTION

Briefly stated, in a preferred aspect, the present application is directed to an intradermal injection adapter having a body defining a longitudinal axis and a central portion located distally relative to the body along the longitudinal axis. The central portion has a cannula channel therethrough extending generally parallel to the longitudinal axis. A cannula fixed within the cannula channel has a sharpened tip for injection into a patient and a sharpened opposite proximal end for injection into a pen injector. A distal protrusion has a first skin contacting surface extending generally parallel to the longitudinal axis. The first skin contacting surface is spaced from the cannula such that a distal portion of the cannula extends generally parallel to the first skin contacting surface.

DETAILED DESCRIPTION OF THE INVENTION

Certain terminology is used in the following description for convenience only and is not limiting. The words “right,” “left,” “lower,” and “upper” designate directions in the drawings to which reference is made. The words “inwardly” or “proximally” and “outwardly” or “distally” refer to directions toward and away from, respectively, the geometric center or orientation of the adapter, adapter and syringe assembly, adapter and pen assembly, or other related parts thereof. The words, “connect,” “connectable” and “connected” mean joined or linked together, either by direct engagement or through intermediate components. The terminology includes the above-listed words, derivatives thereof and words of similar import.

Referring toFIGS. 1-5, a first preferred embodiment of the present invention is directed to an intradermal injection adapter10for mounting to a syringe12having a cannula14for making an intradermal injection in a patient's skin S. In the first preferred embodiment, the adapter includes a side opening22that extends along an entire length of the adapter10, generally parallel to the longitudinal axis18. The side opening22permits insertion of the syringe12into the adapter10for injecting medicament into a patient in an assembled configuration, wherein a tip14aof a cannula14is spaced distally relative to a cannula channel edge26aof the adapter10and is generally fixed in this position in the assembled configuration. The side opening22specifically permits a medical professional to engage the syringe12with the adapter10prior to injection of the medicament into the patient. Typically, the adapter10is packaged in a sterile package and removed from the package for assembly with the syringe12prior to injecting the medicament into the patient. Accordingly, a plurality of packaged adapters10and a plurality of syringes12can be stored at an injection site and assembled when necessary for injecting medicament into patients.

The adapter10is not limited to inclusion of the side opening22(seeFIGS. 6-7), but the side opening22permits relatively easy assembly or engagement of the syringe12with the adapter10. For example, the adapter22may be sold as an individual, sterile unit to a medical organization or other user and mounted to a pre-filled syringe12before injection of the medicament into the skin S. However, the adapter10may also be configured to eliminate the side opening22such that the syringe12is introduced into the syringe channel20through a proximal end portion16aof a body16of the adapter10(seeFIGS. 6-7). In addition, the adapter10may be configured such that the adapter10is permanently affixed to or molded to the syringe12wherein the body16is permanently attached, adhesively bonded, formed or is otherwise permanently affixed or attached to the syringe12. The adapter10is preferably used by healthcare professionals, but may also be used by non-healthcare professionals, potentially for self-injection and typically when the adapter10is pre-assembled to the syringe12.

The intradermal injection adapter10also includes a central portion24having a cannula channel therethrough extending generally parallel to the longitudinal axis18. The cannula channel defines the cannula channel edge26athat tapers slightly distally in the first preferred embodiment, but may be oriented generally perpendicular or otherwise to the longitudinal axis18. For example, the cannula channel edge26amay be oriented in various configurations or at various orientations to accommodate introduction of the cannula14into the cannula channel26, to align the cannula14with the adapter10or for various other design considerations. In the assembled configuration, at least a portion of the cannula14is received within the cannula channel26and a distal portion of the cannula14extends beyond the cannula channel26. The cannula channel edge26ais not limited to being positioned generally perpendicular to the longitudinal axis18and may be pitched or otherwise oriented relative to the longitudinal axis18and is slightly pitched relative to the longitudinal axis18in the first preferred embodiment (seeFIG. 4).

In the first preferred embodiment, a demarcation plane27is defined where the cannula14extends over the channel edge26a, is generally perpendicular to the longitudinal axis18and intersects the longitudinal axis18. The tip14aof the cannula14is positioned distally relative to the demarcation plane27when the syringe12and the adapter10are in the assembled configuration and the cannula14and tip14agenerally maintain their position relative to the demarcation plane27in the assembled configuration and through the injection process.

In the first prepared embodiment, a second skin contacting surface28extends proximally from the cannula channel edge26aat a taper angle Δ. The taper angle Δ may be set or adapted to accommodate dimensions of the adapter10and/or the associated syringe12. At least a portion of the second skin contacting surface28preferably tapers proximally from the channel edge26aat a relatively shallow angle such that the second skin contacting surface28may smoothly slide along the patient's skin S. The second skin contacting surface28is not limited to being generally planar or conical, may be oriented at different angles, may have a portion that is generally perpendicular relative to the longitudinal axis18(seeFIG. 7), may be arcuate or slightly curved or even have a portion that is generally linear and additional portions that are arcuate and/or curved.

A distal protrusion30extends generally parallel to the longitudinal axis18from the central portion24. In the first preferred embodiment, the distal protrusion30includes a sloped distal nose32that curves away from the longitudinal axis18. The sloped or curved distal nose32assists the user or medical professional in arranging the adapter10relative to the patient's skin S and generally limits scrapping or rough engagement of the distal nose32with the patient's skin S to limit the patient's pain and discomfort. The sloped or curved distal nose32also promotes a relatively smooth sliding of the adapter10along the patient's skin S while inserting the cannula14into the patient's skin S and guiding the adapter10along a path generally parallel or slightly pitched relative to the patient's skin S such that the cannula14is inserted into the patient's skin S with the tip14apositioned in the dermis or dermal layer. The distal protrusion30is not limited to inclusion of the distal nose32that generally slopes away from the longitudinal axis18and may include a blunt-edge at a distal end, may be tapered or may be otherwise configured to assist the user or medical professional in positioning the adapter10relative to the patient's skin S.

In the first preferred embodiment, the distal protrusion30is generally transparent distally relative to the demarcation plane27such that the cannula14can be viewed through the distal protrusion30during insertion of the cannula14into the skin S and generally during the entire intradermal injection process. Having a generally transparent distal protrusion30permits the medical professional, nurse or even the patient to view the cannula14through the distal protrusion30to ensure that the cannula14and, particularly, the tip14ais inserted into the patient's skin S during injection. For example, a medial professional may position the cannula14relative to the user's skin and inadvertently fail to penetrate the skin S in sloped or rough areas. Such a mis-insertion may cause the user or medical professional to activate the syringe12to eject the medicament without the tip14apositioned in the skin S, thereby losing or wasting the medicament. Ejecting the medicament with a mis-placed cannula14wherein the cannula14is not positioned in the dermal layer of the patient's skin S wastes the medicament, which can be relatively expensive and often requires a second injection, thereby typically causing additional pain and discomfort for the patient. Such a situation may also result in the patient not being vaccinated, potentially without the knowledge of the medical professional or other user. Accordingly, it is preferred that the distal protrusion30is relatively transparent such that the medical professional, nurse and/or patient can confirm that the cannula14is positioned beneath the surface of the patient's skin S prior to injection. However, the distal protrusion30is not limited to being generally transparent and may be opaque.

The distal protrusion30includes a first skin contacting surface34that extends generally parallel to the longitudinal axis18. In the injecting position, the first skin contacting surface34contacts the surface of the patient's skin S to position the tip14aof the cannula14at a predetermined depth into the skin S such that the tip14ais positioned in the dermal layer of the skin S and the medicament is injected into the dermal layer for absorption. The first skin contacting surface34is preferably not discontinuous or does not include an opening or hole at or near the tip14ato limit the potential that the skin S pushes into the opening or hole, thereby causing the tip14ato be positioned too deep into the patient's skin S or even in a subcutaneous space. Accordingly, the generally continuous first skin contacting surface34generally controls a distance between the tip14aof the cannula14and the first skin contacting surface34to increase the likelihood that the tip14ais positioned in the dermal layer in an injection position (FIG. 2).

In the first preferred embodiment, a first alignment ramp36is positioned within the cannula channel26and is configured to orient the cannula14generally parallel to the first skin contacting surface34in an assembled configuration (FIG. 2). Orienting the cannula14generally parallel to the first skin contacting surface34is preferred to control the spacing of the cannula14relative to the first skin contacting surface34such that the tip14ais positioned in the dermal layer of the patient's skin S in the injection position (FIG. 2).

The adapter10of the first preferred embodiment also includes a second alignment ramp38positioned within the cannula channel26that is configured to orient the cannula14, in cooperation with the first alignment ramp36, generally parallel with the first skin contacting surface34in the assembled configuration. The second alignment ramp38is preferably positioned distally in the cannula channel26relative to the first alignment ramp36and the cannula14is preferably in facing engagement with the first and second alignment ramps36,38in the assembled configuration. The adapter10is not limited to inclusion of either the first alignment ramp36or the second alignment ramp38to align at least the distal section of the cannula14generally parallel to the first skin contacting surface34and may include numerous alternative alignment mechanisms or no specific alignment mechanism in the central portion24or within the cannula channel26. For example, the cannula channel26may include a V-shaped groove that aligns the cannula14generally parallel to the first skin contacting surface34, a clamping mechanism that aligns the cannula14with the first skin contacting surface34or numerous alternative alignment mechanisms to preferably arrange the cannula14generally parallel to the first skin contacting surface34. In addition, the cannula14is not necessarily oriented generally parallel to the first skin contacting surface34and may be alternatively arranged such that the tip14aof the cannula14is configured for positioning in the dermal layer of the skin S without being aligned generally parallel to the first skin contacting surface34.

The cannula channel26is defined by the first skin contacting surface34, the lateral cannula wall40and the alignment wall42in the first preferred embodiment and is generally contained in the central portion24. The cannula14is preferably positioned adjacent the lateral cannula wall40in the assembled configuration. Accordingly, the first and second alignment ramps36,38and the lateral cannula wall40align the cannula14generally parallel to the first skin contacting surface34in the assembled configuration and generally center the cannula14along the longitudinal axis18in the assembled configuration. However, the cannula14is not limited to being aligned and centered utilizing the first and second alignment ramps36,38and the lateral wall40as was described above and may be otherwise aligned and oriented by the adapter10such that the tip14ais positioned in the dermal layer of the patient's skin in the injecting configuration. In addition, the cannula14is not limited to being generally coaxial with the longitudinal axis18in the assembled configuration and may be mis-aligned or slightly pitched relative to the longitudinal axis18as long as the tip14is generally positioned in the dermal layer in the injection position.

Referring toFIG. 4, the first skin contacting surface34is spaced a relatively consistent distance from the distal portion of the cannula14. The first skin contacting surface34is also generally continuous between an area adjacent a tip14aof the cannula14and an area adjacent the channel edge26ain the assembled configuration. In the first preferred embodiment, the syringe12may be generally coaxial with the longitudinal axis18and the distal portion of the cannula14is pitched slightly upwardly away from the longitudinal axis18to come into generally parallel alignment with the first skin contacting surface34in the assembled configuration. The distal portion of the cannula14is preferably spaced at a cannula gap distance X from the first skin contacting surface34. The cannula gap distance X is preferably at least two tenths of a millimeter (0.2 mm) and may be within a range of two tenths of a millimeter to two millimeters (0.2-2 mm). However, the cannula gap distance X is not limited to being in this range and may be comprised of nearly any distance that permits the tip14aof the cannula14to be positioned in the dermal layer of the patient's skin S in the injection position. In the first preferred embodiment, the cannula gap distance X is approximately fifty-five hundredths of a millimeter (0.55 mm). In addition, a more preferred range for the cannula gap distance X is approximately four tenths of a millimeter to eight tenths of a millimeter (0.4-0.8 mm). The cannula14of the first preferred embodiment may be a cannula gage27and the cannula gap distance X between the first skin contacting surface34and an outer diameter of the cannula14may be fifty-five hundredths of a millimeter (0.55 mm) or greater, generally resulting in the tip14aof the cannula14being positioned within the dermal layer in the injection position. The cannula gap distance X may be impacted by the orientation of the cannula14(lancet up or lancet down), gage of the cannula14, expected location of injection in the patient and numerous other factors that may be considered by the designer.

In the first preferred embodiment, the tip14aof the cannula14is positioned approximately one and one-half to ten millimeters (1.5-10 mm) along the longitudinal axis18from the demarcation plane27defined where the cannula14extends over the channel edge26a. The demarcation plane27intersects and is generally perpendicular to the longitudinal axis18. In the first preferred embodiment, the tip14aof the cannula14is positioned distally beyond the demarcation plane27, defined where the cannula14extends over the channel edge26a, at an exposed length L1. The exposed length L1is not limited to the above-described one and one-half to ten millimeters (1.5-10 mm) and may have nearly any length that permits insertion of the tip14ainto the dermal layer of the patient's skin S in the injection configuration. In a more preferred range, the exposed length L1is approximately two and one-half to seven millimeters (2.5-7 mm) and in a further preferred range, the exposed length L1is approximately two and one-half to four millimeters (2.5-4 mm). In the assembled configuration, the exposed length L1is preferably predetermined during the design of the adapter10and the cannula14generally does not move or slide relative to the adapter in the assembled configuration. Accordingly, once the syringe12is engaged with the adapter10of the first preferred embodiment, the exposed length L1generally does not change and the cannula14and associated syringe12do not slide relative to the body16, the central portion24and the distal protrusion30.

The distal protrusion30of the first preferred embodiment is generally clear or transparent, at least distally toward the distal nose32relative to the demarcation plane27, and is generally cloudy or opaque proximally of the demarcation plane27. The central portion24and the remainder of the adapter10are also preferably cloudy or opaque. Providing a generally transparent distal protrusion30, at least distally of the demarcation plane27, and a generally opaque distal protrusion30and adapter10proximally of the demarcation plane27provides a visual cue to a medical professional or user that the cannula14is penetrating the skin S during injection and that the skin S is in facing engagement with the first skin contacting surface34in the injection position. The distal portion of the cannula14may appear to disappear or be completely positioned beneath the skin S in the injection position due to the generally transparent distal protrusion30distally relative to the demarcation plane27and cloudy or opaque remainder of the adapter10, as the proximal portion of the cannula14that is positioned proximally to the demarcation plane27may be obscured by the opaque or cloudy portions of the adapter10. This disappearance of the cannula14also provides a visual cue to the medical professional or user that the cannula14penetrates the skin S a sufficient distance and additional insertion pressure or force is not required to insert the cannula14. This visual cue can be particularly useful for “heavy-handed” medical professionals or users who may apply excessive pressure in the injection position and potentially cause skin S to bunch between the first skin contacting surface34and the cannula14, which could cause damage to the cannula14or result in the tip14abeing positioned outside of the intradermal layer.

Designing the distal protrusion30with a generally transparent portion distally and a generally opaque portion proximally of the demarcation plane27permits the medical professional or user to visually confirm that the distal portion of the cannula14that extends beyond the cannula channel edge26ahas entered the patient's skin S and the skin S is in relatively consistent contact with the first skin contacting surface34, which provides a visual indication to the medical professional or user that the tip14aof the cannula14is positioned in the dermis or dermal layer of the patient's skin S such that the medicament will be injected into the dermis or dermal layer of the patient's skin S for absorption into the patient's body.

In the first preferred embodiment, a tip14aof the cannula14is preferably spaced at an overhang length L2from a distal edge of the distal nose32(seeFIG. 4). The overhang length L2is preferably at least one millimeter (1 mm), particularly if the adapter10does not include the upturned distal nose32. In the first preferred embodiment, the overhang length L2is approximately two to six millimeters (2-6 mm). The overhang length L2provides some safety to users and patients from receiving an inadvertent puncture from exposure to the tip14a, for example, if a medical professional attempts to introduce the cannula into the skin S generally perpendicular to the skin S or inadvertently approaches the skin S generally perpendicularly to the skin S, and also provides a section of relatively constant cannula gap distance X between the tip14aand the demarcation plane27in the assembled configuration to correctly position the tip14ain the skin S during insertion. The cannula gap distance X is preferably consistent between the demarcation plane27and the tip14as a result of at least the distal portion of the cannula14extending generally parallel to the first skin contacting surface34. The first skin contacting surface34also preferably extends beyond the tip14aalong a generally linear or parallel path, at least for a limited distance before the distal nose32begins to curve upwardly and this extended distance may be approximately one to two millimeters (1-2 mm). The overhang length L2is not limited to the above-described dimensions and may have nearly any dimension that limits exposure to the tip14aand facilitates insertion of the cannula14into the skin S at a desired depth from the surface of the skin S. The overhand length L2also generally prevents perpendicular insertion of the cannula tip14ainto the patient's skin S. Attempts at perpendicular insertion of the cannula tip14ainto the patient's skin S typically produces inaccurate positioning of the tip14ain the dermal layer and injection of the medicament into an undesirable section of the skin S.

Referring toFIGS. 1 and 2in the first preferred embodiment, the syringe12includes a barrel44, a plunger46with a piston46aslidable and sealingly engaged within a hollow cavity44aof the barrel44and the cannula14. The barrel44ahas a generally cylindrical configuration and the hollow internal cavity44areceives the medicament therein. The medicament is typically stored between the piston46aand the cannula14in the hollow internal cavity44a. The syringe12is not limited to inclusion of the barrel44, plunger46and cannula14and may be comprised of nearly any device that is able to retain medicament therein, be joined with the adapter10and expel the medicament therefrom or otherwise inject the medicament into the dermal layer of the patient's skin S in operation. For example, the syringe12may be comprised of a pre-filled syringe12without a cannula14wherein the cannula14is associated with the adapter10(see, e.g.,FIGS. 11 and 12).

In the first preferred embodiment, the adapter10includes at least the body16, the distal nose32, the central portion24and the syringe channel20that extends generally parallel to the longitudinal axis18through the body16. The body16includes the syringe channel20and is preferably positioned proximally on the adapter10relative to the central portion24, which includes the cannula channel26. The syringe channel20receives at least a portion of the syringe12and, particularly, at least a portion of the barrel44in the assembled configuration. The adapter10also includes the side opening22that preferably extends along an entire length of the adapter10between the proximal portion16aand the distal nose32or at least to the end of the central portion24near the cannula channel edge26a. The side opening22permits selective insertion of the syringe12and cannula14relative to or into the adapter10. The side opening22is preferably slightly narrowed relative to a maximum diameter of the barrel44such that the barrel44is force-fit or snap-fit into the syringe channel20during assembly. The snap-fit or force-fit of the barrel44into the syringe channel20assist in retaining the syringe12in the adapter10following assembly. However, the barrel44is not limited to being snap-fit or force-fit into the syringe channel20and may be alternatively engaged or secured to the adapter10by staking, clamping, adhesive bonding, fastening or otherwise fastening or securing the syringe12to the adapter10.

In the first preferred embodiment, the configuration of the syringe channel20inside opening22defines a narrowed C-shaped clamping section into which the syringe12is force fit in the assembled configuration.

Referring toFIG. 5, the distal protrusion30has a protrusion width W of approximately three to ten millimeters (3-10 mm) to engage the skin S in the injection position (FIG. 2). The protrusion width W is not limited to the three to ten millimeter (3-10 mm) range and may have nearly any width that is maneuverable by the medical professional or user and promotes proper placement of the tip14ain the dermal layer or dermis in the injection position. In the first preferred embodiment, the protrusion width W is approximately the same or slightly smaller than the diameter of the barrel44, but is not so limited. It may be preferable for the protrusion width W to generally match or be slightly smaller than the diameter of the barrel44for storage, packaging, maneuverability and overall handling of the syringe12and adapter10. The protrusion width W is preferably configured to result in minimization of forces required during insertion while generally stabilizing the position of the adapter10relative to the skin S during insertion and in the injection position. The protrusion width W of the distal protrusion30could be narrow relative to the barrel44to integrate other system components or may be larger than the barrel44of the syringe12to generally maximize stability.

Referring toFIGS. 1-3, in the first preferred embodiment, the cannula14has a cannula hub14bthat is preferably, integrally engaged with a narrowed distal portion44bof the syringe12. The cannula14is preferably constructed of a metal material that is bonded into the cannula hub14b, which is typically constructed of a polymeric or plastic material. The adapter10also preferably includes a positioning wall48that is engaged with the narrowed distal portion44bof the barrel44in the assembled configuration. Engagement of the narrowed distal portion44band the positioning wall48generally controls the positioning of the tip14aof the cannula14relatively along the longitudinal axis18to obtain the desired exposed length L1and overhang length L2. Accordingly, the adapter10is preferably configured for syringes12and cannulas14having known dimensions, at least with respect to the position of the narrowed distal portion44brelative to the tip14aof the cannula14such that the positioning of the tip14arelative to the adapter10is controllable. The syringe channel20is also designed and configured to receive and retain the barrel44of the syringe12in the assembled configuration.

In the first preferred embodiment, the adapter10includes a collar50at the proximal end portion16athat can be utilized by a user to handle the adapter10. The collar50may be used to engage the adapter10with the user's fingers to maintain the syringe12in a proper position relative to the adapter10.

The adapter10also preferably includes a finger grasping portion52that can be utilized by the medical professional or nurse to grasp and hold the adapter10and syringe12during use. The finger grasping portion52permits the medical professional or nurse to grasp the adapter10and syringe12proximate the distal nose32to provide control close to the tip14a. During injection, the medical professional typically manipulates the assembled adapter10and syringe12by grasping the barrel44and/or the adapter10.

Referring toFIGS. 6 and 7, in a second preferred embodiment, an adapter10′ has a similar configuration to the adapter10of the first preferred embodiment, but the cannula14′ is fixed to the adapter10′, the body16′ does not include a side opening for receipt of the syringe12′, as well as additional structural and functional differences between the first and second embodiment. The adapter10′ of the second preferred embodiment utilizes the same reference numerals to identify similar features relative to the adapter10of the first preferred embodiment and a prime symbol (′) to specifically identify the adapter10′ of the second preferred embodiment and its components. Accordingly, a significant number of the features of the second preferred embodiment of the adapter10′ are the same or similar to the adapter10of the first preferred embodiment and the features that are different in the adapter10′ of the second preferred embodiment are emphasized in the below description.

In the second preferred embodiment, the cannula14′ is fixed to the adapter10′ such that the tip14a′ is positioned relative to the distal protrusion30′ with the exposed length L1′ and the overhang length L2′ predetermined and typically falling within the above-described predetermined ranges of the first preferred embodiment. In addition, the cannula gap distance X′ is also predetermined and preferably falls within the above-described preferred ranges of the first preferred embodiment. Fixing the cannula14′ to the adapter10′ generally eliminates potential mis-alignment of the cannula14′ relative to the adapter10and, therefore, mis-positioning of the tip14a′ relative to the distal protrusion30′.

In the second preferred embodiment, the adapter10′ is typically associated with a pre-filled syringe (not shown) without the cannula14′ mounted thereto and is typically attached to the proximal end portion16a′ of the body16′ using a conventional Luer. The syringe12′ may be pre-filled by the manufacturer, filled by the medical professional or user prior to injection or otherwise filled prior to engaging the adapter10′ with the pre-filled syringe12′ using a cannula, vial adapter, spike or other mechanism. The syringe12′ is not limited to being mounted to the body16′ by a Luer in the second preferred embodiment and may be otherwise mounted, secured or fastened to the body16′.

Referring toFIGS. 8-12, in a third preferred embodiment, an adapter10″ has a similar configuration to the adapters10,10′ of the first and second preferred embodiments, but the adapter10″ of the third preferred embodiment is designed for use with a pen injector12″ or any other multi-dose, pre-filed automatic injection device, such as those used for the self-injection of insulin. Additional differences between the third preferred embodiment of the adapter10″ and the other embodiments are described below or can generally be identified in the figures. The adapter10″ of the third preferred embodiment utilizes the same reference numerals to identify similar features relative to the adapters10,10′ of the first and second preferred embodiments and a double-prime symbol (″) to specifically identify the adapter10″ and its components of the third preferred embodiment. Accordingly, a significant number of the features of the third preferred embodiment of the adapter10″ are the same or similar to the adapters10,10′ of the first and second preferred embodiments and the features that are different in the third preferred embodiment of the adapter10″ are emphasized in the below description.

In the third preferred embodiment, the pen injector12″ includes a medicament storage volume44″ (for example, a vial, cartridge, or pen injector barrel) and an injection button45″ operatively coupled to a plunger46″ with a piston46a″ slidable within a hollow cavity44a″ of the storage volume44″. The pen injector12″ may include a rotatable dial or a depressible button66″ to allow a user to selectively adjust the dosage of medicament. The pen injector12″ typically includes a drive mechanism (known in the art and not illustrated) to effectuate movement of the piston46a″ to expel the medicament. The storage volume44″ generally has a cylindrical configuration and the hollow internal cavity44a″ receives the medicament therein. The medicament is typically stored between the piston46a″ and a penetrable seal64″ of the storage volume44″ in the hollow internal cavity44a″. Depending on the configuration of the storage volume44″, the seal64″ may connect to an open end of a vial or a cartridge, or to an opening within the distal end of the pen injector12″ barrel. The person of ordinary skill in the art will recognize that adapter10″ could be configured for use with nearly any known syringe device that is able to retain medicament therein, be joined with the adapter10″ and expel the medicament therefrom or otherwise inject the medicament into the dermal layer of the patient's skin S in operation.

In the third preferred embodiment and similar to the second preferred embodiment, a cannula14″ is fixed to the adapter10″ such that a tip14a″ is positioned relative to a distal protrusion30″ with an exposed length L1″ and an overhang length L2″ predetermined and typically falling within the above-described predetermined ranges of the first preferred embodiment. In addition, a cannula gap distance X″ is also predetermined and preferably falls within the above-described preferred ranges of the first preferred embodiment. The adapter10″ is typically attached to a distal end62″ of the pen injector12″ using a threaded connection, such that a body16″ of the adapter10″ preferably includes one or more threads on an interior surface thereof for attachment to the distal end62″ of the pen injector12″. Alternatively, the adapter10″ may be configured to connect with other known pen injector12″ connections, such as that disclosed in U.S. Pat. No. 7,762,994, which is incorporated by reference herein in its entirety.

The entire or almost the entire adapter10″ may be transparent or generally transparent, as shown inFIGS. 11 and 12, or only a portion of the adapter10″ may be transparent, as described above with respect to the first and second preferred embodiments. Alternatively, the entire or almost the entire adapter10″ may be opaque or generally opaque, as shown inFIGS. 8-10.

In the third preferred embodiment, the cannula14″ is a dual tipped needle or a double end needle. In other words, in addition to the distal tip14a″ of the cannula14″ being sharp or pointed for injection into the skin S of a patient, an opposite proximal end or tip14b″ of the cannula14″ is sharp or pointed for injection into at least a portion of the hollow internal cavity44a″ of the storage volume44″ of the pen injector12″. The distal tip14a″ and opposite proximal end14b″ of the cannula14″ are preferably identical or nearly identical in size and shape. Thus, the proximal end14b″ of the cannula14″ is easily capable of penetrating the seal64″ of the pen injector12″, so that medicament or other fluid can flow from the pen injector12″, through the cannula14″ and into the patient's skin S.

Referring toFIGS. 1-5, in operation of the first embodiment of the adapter10, the syringe12is either provided pre-filled or the medicament is aspirated into the syringe12from a vial (not shown). The syringe12may be separate from the adapter10to aspirate the medicament into the syringe12and a different cannula14may be utilized to aspirate the medicament into the syringe12than is used to inject the medicament into the patient. For example, a relatively large gage cannula14may be used to aspirate the medicament into the barrel44and the relatively large gage cannula14may be replaced with a smaller gage cannula14for injection. Alternatively, the central portion24and distal protrusion30may be hingedly mounted to the barrel44and/or hub14band the cannula14such that the central portion24and distal protrusion30may be pivoted away from the cannula14during aspiration of medicament from the vial into the syringe12and then pivoted back into the assembled configuration for the injection procedure.

After medicament is in the syringe12, the syringe12is mounted to the adapter10. Preferably, the syringe12is press-fit through the side opening22into the syringe channel20to engage the syringe12with the adapter10. In the assembled configuration, the narrow distal portion44bis preferably positioned in facing engagement with the positioning wall48to properly locate the tip14arelative to the adapter10. Once the narrow distal portion44bis positioned in facing engagement with the positioning wall48, the cannula14generally does not move relative to the adapter10.

In the preferred assembled configuration, at least a portion of the cannula14is positioned within the cannula channel26. During insertion from the side, the cannula14is guided into the cannula channel26by moving along the upslope surfaces36a,38aof the first and second alignment ramps36,38, over the apex surfaces36b,38band along the downslope surfaces36c,38c. In the assembled configuration, the cannula14is preferably positioned in facing engagement with the downslope surfaces36c,38cand the lateral cannula wall40. Positioning of the needle14in this configuration urges the cannula14into generally parallel alignment with the first skin contacting surface34such that the cannula14is spaced from the first skin contacting surface34by the cannula gap distance X. The cannula gap distance X is preferably predetermined such that the tip14ais positioned in the dermal layer of the patient's skin S in the injection position.

To inject the medicament into the patient's skin S, the user may grasp the finger grasping portion52and/or the barrel44and urge the adapter10into engagement with the patient's skin S. The adapter10is oriented relative to the patient's skin S such that the longitudinal axis18is slightly less than parallel or nearly parallel relative to the user's skin S. Referring specifically toFIG. 2A, the adapter10may be urged slightly downwardly toward the skin S and is subsequently urged toward or slides along the user's skin S such that at least the first skin contacting surface34is in engagement with a surface of the epidermis of the skin S. As the adapter10slides along the skin S, the distal nose32promotes relatively smooth sliding of the adapter10along the skin S. The cannula14generally does not move relative to the adapter10during the injection process and the cannula14preferably enters the skin S for approximately the entire exposed length L1. The medical professional or user is able to visually inspect the cannula14entering the skin S and the surface of the epidermis contacting the first skin contacting surface34through the transparent distal portion of the distal protrusion30, which is demarcated by the preferred transparent to opaque transition of the distal protrusion30at the demarcation plane27. In a fully engaged injection position, the user or medical professional may visually observe that the entire portion of the cannula14positioned distally of the demarcation plane27is positioned within the skin S. Accordingly, the medical professional may note that the cannula14is not visible through the relatively transparent portion of the distal protrusion30because the cannula14is located within the skin S. During insertion and injection, the medical professional or nurse is also able to view the tip14aentering the skin S through the generally transparent distal protrusion30. In addition, the nurse or medical professional is generally able to see the skin S contacting the first skin contacting surface34through the distal protrusion30. Further, the first and second skin contacting surfaces34,28promote positioning of the cannula14relative to the skin S to further promote positioning of the tip14aof the cannula14into the dermal layer. In the injection position, the tip14aof the cannula14is positioned in the dermis of the skin S.

Once the tip14aof the cannula14is properly positioned in the skin S, the plunger46is depressed, thereby urging the piston46ato push the medicament out of the barrel44, through the cannula14, out of the tip14aand into the dermal layer. The medicament is absorbed into the dermal layer to provide clinical benefits to the patient.

The cannula gap distance X is designed to position the tip14aof the cannula14in the dermal layer in the injection position (FIG. 2). Although the epidermis and dermal layers of the skin S can have variable thicknesses, the cannula gap distance X is designed to result in the tip14abeing positioned in the dermis or at the lower portion of the epidermis in the injection position for the most common thicknesses of the epidermis and dermis of typical skin S. Accordingly, the combination of the adapter10and the syringe12provide a relatively high likelihood that the tip14ais positioned in the dermis or dermal layer and provides clinical benefit for the patient by applying the medicament directly to the preferred layer of the skin S. Following injection, the syringe12and adapter10are withdrawn away from the skin S, typically in an opposite direction from insertion and the syringe12and adapter10are discarded.

Referring toFIGS. 1,6,7and8-12, in operation of the second and third preferred embodiments of the adapter10′,10″, the injection process is typically the same with the exception that the pre-filled syringe12or pen injector12″ without the cannula14is mounted to the proximal end portion16a′,16a″ of the body16′,16″ and the cannula14′,14″ is fixed to the adapter10′.