IONTOPHORETIC DRUG DELIVERY METHOD
20170120047 ยท 2017-05-04
Inventors
Cpc classification
A61N1/30
HUMAN NECESSITIES
A61N1/325
HUMAN NECESSITIES
International classification
A61N1/30
HUMAN NECESSITIES
Abstract
The present invention relates generally to iontophoretic drug delivery systems for transdermal delivery of therapeutic agents and, more particularly, to packaging such systems for long shelf life and easy assembly for use. The system package includes an iontophoretic skin worn patch component that accommodates a power source, electronics, electrodes and a drug pack component that carries a therapeutic agent which is contained as a separate sealed component. The packaged system further provides for ease of assembly at the time of use.
Claims
1. A method of administering a therapeutic agent to a patient with an iontophoretic drug delivery system, the method comprising the steps of: (a) removing a drug pack component of the iontophoretic drug delivery system and an iontophoresis patch component of the iontophoretic drug delivery system from a storage package and removing one or more of the cover membranes and release liners; (b) assembling the iontophoretic drug delivery system by combining the drug pack component and the iontophoresis patch component, the assembling step including aligning the drug pack component and the iontophoresis patch component relative to one another with an alignment structure and affixing the drug pack component and the iontophoresis patch component into permanent adhesive contact forming a transdermal iontophoresis patch that is ready to use, wherein said alignment structure is either: (1) a folding support structure associated with the drug pack component and the iontophoresis patch component, the folding support structure including a separator component configured to physically separate and protect the drug pack component and the iontophoresis patch component when the iontophoretic drug delivery system is present in a folded storage state; or (2) a separate guide element including a raised alignment members configured to register with the drug pack component and the iontophoresis patch component for separate consecutive alignment of the drug pack component with the iontophoresis patch component; and (c) applying the transdermal iontophoresis patch to the skin of the patient at a desired location.
2. The method according to claim 1 wherein the iontophoresis drug delivery system comprises a patch skin adhesive layer and the one or more release liners comprise a half release liner, and wherein about one half of the patch skin adhesive layer is exposed initially when the patch is applied to the skin followed by removal of the half release liner to achieve full patch adhesion.
3. The method according to claim 1, further comprising the step of: unfolding the drug pack component from the iontophoresis patch component to access the separator component for removal.
4. The method according to claim 1, further comprising the step of: removing the transdermal iontophoresis patch from the folding support structure prior to applying the transdermal iontophoresis patch to the skin of the patient.
5. The method according to claim 1 wherein said drug pack component includes a pair of gel pads including an anode gel pad and a cathode gel pad isolated prior to assembly by a cover membrane having low moisture permeability.
6. The method according to claim 5, further comprising the step of: activating a current configured to draw the therapeutic agent from the gel pad through the skin of the patient.
7. The method according to claim 5 wherein said gel pads comprise one or more layers of non-woven polymer matrix.
8. The method according to claim 5 including an amount of therapeutic agent ion species located in gel associated with at least one of said gel pads.
9. The method according to claim 5 wherein said gel pads are fixed to a substrate layer in said drug pack by adherence of a gel material prior to assembly of said system.
10. The method according to claim 5 wherein said therapeutic agent is present in said gel in a concentration from about 0.2% to 10%.
11. The method according to claim 5 wherein said iontophoresis patch component includes electrodes comprising an anode and a cathode and a source of electric power.
12. The method according to claim 11 wherein said drug pack component comprises the gel pads and the electrodes are contained in recesses adapted to receive the gel pads of the drug pack upon assembly of the transdermal iontophoresis patch.
13. The method according to claim 5 further comprising a peripheral adhesive layer bonding the gel pad to an electrode in the transdermal iontophoresis patch.
14. The method according to claim 1 wherein said cover membrane having low moisture permeability comprises a material selected from the group consisting of metal/polymer composites and PVC.
15. A method of administering a therapeutic agent to a patient with an iontophoretic drug delivery system, the method comprising the steps of: removing a separator component from a drug pack component having a gel pad, the separator component configured to be interposed between and thereby physically separate and protect the drug pack component and an iontophoresis patch component when the iontophoretic drug delivery system is present in a fully folded storage stage; folding a folding support structure to align an iontophoresis patch component with the drug pack component, wherein said iontophoresis patch component is configured to align said gel pads of said drug pack component in conductive relation in an assembled state, the folding support structure is associated with the drug pack component and the iontophoresis patch component; and applying the iontophoretic drug delivery system in the assembled state to the skin of the patient.
16. The method according to claim 15, further comprising the step of: unfolding the drug pack component from the iontophoresis patch component to access the separator component for removal.
17. The method according to claim 15, further comprising the step of: removing the iontophoretic drug delivery system in the assembled state from the folding support structure prior to applying the iontophoretic drug delivery system in the assembled state to the skin of the patient.
18. The method according to claim 15, further comprising the step of: activating a current configured to draw the therapeutic agent from the gel pad through the skin of the patient.
19. The method according to claim 15, wherein said drug pack component include a pair of gel pads including an anode gel pad and a cathode gel pad isolated prior to assembly by a cover membrane having low moisture permeability.
20. The method according to claim 19 wherein said gel pads comprise one or more layers of non-woven polymer matrix.
21. The method according to claim 19 including an amount of therapeutic agent ion species located in gel associated with at least one of said gel pads.
22. The method according to claim 19 wherein said gel pads are fixed to a substrate layer in said drug pack by adherence of a gel material prior to assembly of said system.
23. The method according to claim 21 wherein said therapeutic agent is present in said gel in a concentration from about 0.2% to 10%.
24. The method according to claim 15 wherein said iontophoresis patch component includes electrodes comprising an anode and a cathode and a source of electric power.
25. The method according to claim 24 wherein said drug pack component comprises the gel pads and said electrodes are contained in recesses adapted to receive said gel pads of said drug pack upon assembly of said system into said assembled state.
26. The method according to claim 15 further comprising a peripheral adhesive layer bonding the gel pad to an electrode in the assembled state.
27. The method according to claim 19 wherein said cover membrane having low moisture permeability comprises a material selected from the group consisting of metal/polymer composites and PVC.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
[0020] In the drawings wherein like characters denote like parts throughout the same:
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DETAILED DESCRIPTION
[0040] The invention provides for a fully functional, self-contained, easy-to-use iontophoresis device in the form of a pre-packaged drug delivery system which enjoys a relatively long stable shelf life. The system contains a drug reservoir pack, folding panel support structure construction, and a transdermal patch containing a power source, current controlling electronics, and electrodes. The device is ready to use and requires only a few simple operations to activate and apply the patch to a treatment site. The operations in some embodiments consist of removing a drug pack barrier lid, folding the panels onto themselves, and peeling the patch from a release coating. In others, the transdermal patch and drug pack are assembled on an alignment fixture or guide element which is then removed. Several preferred embodiments of the devices will be described below to illustrate the concepts of the invention, but they are not meant to limit the scope of the inventive concept in any manner.
[0041]
[0042] The folding support structure 22 may include a paperboard, or similar material, substrate with a release coating layer 28 applied to one side and a printable coating 30 applied to the opposite side.
[0043] As shown, transdermal iontophoretic patch 24 is adhesively attached to a first panel 36A of the support structure 22 on the release coated side of the substrate. The transdermal iontophoretic patch 24 includes an adhesive coated foam layer 38, an occlusive double sided tape layer 40, an electrode subassembly layer 42 consisting of a power source, electronics and electrodes to operate the patch (not shown), and an overlay tape layer 44. As shown in
[0044] As shown in
[0045] The half-panel release liner serves the purpose of stiffening the flexible patch to aid in application and additionally allows the operator to handle the patch easily without the patch sticking to the operator's fingers. Preferably, the half of the patch not covered by the half-panel release liner 54 is affixed to the patient's skin first. Subsequently, the half-panel release liner is removed by peeling at a tab 54A of the half-panel release liner. Finally, the other half of the patch is affixed to the patient's skin.
[0046] A strip of double-sided tape 56 is attached to the printable side of the support structure 22 on the first panel 36A. The adhesive strip 56 serves a dual function of keeping the structure closed during its long term storage condition by temporarily bonding to a release coated side as shown in
[0047] As shown in
[0048] As shown in
[0049] A second piece of double-sided tape 66 is attached to the second panel 36B on the printable side of the support structure 22 to permanently bond the drug containing blister pack 26 to the support structure 22. Alternatively, for example, instead of a double-sided adhesive 66, the drug containing blister pack 26 could be heat sealed to the support structure 22 as by applying a heat seal coating to the bottom of the drug containing pack or to the printable side of the support structure.
[0050] As indicated, the drug pack 26 is provided with a formed barrier lid having low moisture vapor permeability, a generally flat bottom layer, containing two spaced gel locations, one containing an anode gel-imbibed non-woven pad 60, another containing a cathode gel-imbibed non-woven pad 62. The low moisture vapor permeable barrier formed lid layer is shown at 64. Preferably, the generally flat bottom layer 68 is constructed of an aluminum foil composite film that may or may not contain a heat seal coating (not shown) on the side that contacts the gel pads. If it is used, the heat seal coating is preferably a readily peelable coating.
[0051] The gel-imbibed pads as at 58 are constructed of a composite or laminated non-woven material. The anode and cathode gels are dispensed onto the pads and soak into the composite non-woven material.
[0052] The low moisture vapor permeable formed lid layer 64 has been successfully constructed from a cold-formable aluminum composite material consisting of a seal layer on the product contacting under side and a nylon layer on the opposite side. Alternatively, for example, the product contact side 64 may consist of PVC with no seal layer. If a seal layer is employed, preferably it is a peelable heat seal coating. Anode 72 and cathode 74 cavities may be mechanically formed with traditional cold form tooling using Teflon (polytetrafluorethylene) plugs or in combination with vacuum or pressure assist. The material may be thermoformed if using an alternative material including other fluorine-containing plastics in sheet or film form such as material sold under the trademark Aclar, PVDC, and other low moisture vapor transmission barrier thermoformed packaging materials.
[0053]
[0054] In one embodiment, both the anode 72 and cathode 74 composite pads are similar in shape. Of course, the electrodes may be any convenient shape and the electrodes in a given patch embodiment may be of like or different shapes.
[0055] An important aspect of the invention involves shelf life stability of the co-packaged iontophoretic devices. This is of paramount concern based on the history of such devices which have had limited commercial success because of shelf life limitations. As indicated, co-packaging techniques have included attempts to package the wet drug gels in direct contact with the electrodes during long term storage, and attempts to isolate the power source and electronics in the same package through low moisture permeable (high barrier) materials. Wet gels have been packaged in direct contact with the electrodes only and connected to a power source and electronics by a cable or other connector at time of use. As indicated, each of these is fraught with challenges for long term stability. For example, in time, wet gels may degrade the metals in the electrodes, power source, and electronics which, in turn, contaminates and degrades the stability of the gel.
[0056] In the present development, stable long term co-packaging is realized by the provision of a storage container for the anode and cathode gels in the form of a separate hermetically sealed drug pack or blister cavity with product contact layers that do not leach into the gel, react with the gel, or absorb the gel. Since the gel material itself provides no form, a carrier substrate material is used to give the gel form and structure, and provide a stable support to facilitate transfer of the gel out of the long term storage container when the system is assembled for use. The carrier substrate should be composed of materials that do not leach, react, or absorb the constituents of the gel. Preferably the blister cavity and carrier substrate should be made from stable, relatively inert, materials such as polypropylene and polyethylene. Any suitable material can be used and may be selected based on the nature of the gel.
[0057] Shelf life stability will vary with the construction of the patch component and the stability of the integrity of the drug composition. Patch shelf life depends on retention of adhesive quality and the maintenance of the specified function of the electrical circuit components. The device should have a stable shelf life of at least two (2) years.
[0058]
[0059] The remaining steps are performed in a timed sequence as will be described. Allowable open time for the assembly is determined by the rate of pad permeation which is related to the viscosity of the gel used.
[0060] At time t=t.sub.0, as shown in
[0061] Alternatively, in another embodiment (not shown), the flat bottom layer can be formed similarly to the formed cover membrane layer to create a nested configuration, in which case, the gel plus the pad height can be designed so that when the bottom and lid layers are assembled, the gel will be in contact with the carrier substrate layer in a similar manner as in the illustrated embodiment.
[0062] In this procedure, time span t=t.sub.0 to t=t.sub.1 is defined as the time it takes the dispensed anode and cathode gels to soak through their respective pads and start to wet to the bottom of the formed cavities of lid layer. Time is a factor because it has been found that if the gels soak completely through the respective pads and wet the bottom or inner surface of the formed cover membrane cavity before the carrier substrate layer is applied, the pads, once fully imbibed, may preferentially stick to the inside of the formed lid. This, of course, is undesirable as the imbibed gel pad would adhere to the lid layer 122 instead of the carrier substrate layer 140 when one attempted to assemble the system. Time span t=t.sub.0 to t=t.sub.1 also defines the time in which the gel will adequately maintain its height so that the gel will wet and adhere to the inner surface of the bottom layer 140 when that layer is applied.
[0063] For the above reasons, the gels are formulated in a preferred viscosity range to provide the correct flow rate and surface tension. For example, a 100,000 centipoise gel may have a t.sub.0-t.sub.1 time window of about 2-4 minutes. This is adequate for normal assembly to occur.
[0064] In this process, the gels initially contact and wet the bottom layer member 140. This allows the gels to act as adhesives as the surface tension of the gels between the member 140 and the pads 128 and 130 exceeds the gravitational forces on the imbibing pads. Therefore, as the pads slowly imbibe with gel, they will stick to and be pulled towards the carrier substrate layer regardless of the orientation of the device. Thus, after the bottom and lid layers are sealed, the compressed gels imbibe (soak-in) into the anode and cathode pads respectfully, creating a fully imbibed non-woven anode pad 128A and fully imbibed pad 130B as shown in
[0065] It will be appreciated that the amount of gel added to each cavity should be matched to the absorbency of each pad in order to minimize excess gel. The amount and viscosity of the gels is preferably such that imbibed gel does not wet the outer surface of the occlusive ring on the pads. In this manner, the outer surface of the occlusive ring 146, 148 should remain relatively dry to aid adhesive transfer and adhesive attachment of imbibed gel pads into corresponding empty anode and cathode wells of the transdermal patch during activation. The inside surface of the formed lid cavities in the anode and cathode headspace regions as at 142 and 144 should remain free of gel and relatively dry.
[0066] In order for this packaging concept to function, the gels must be formulated with a preferred viscosity. The preferred range is between 8,000-120,000 centipoise but is not limited so long as the process can be successfully followed. The gels useful in the system may be formulated by dissolving an appropriate amount of drug or saline in water, and adding a gelling agent such as HPMC (hydroxpropylmethylcellulose) such that a conductive gel of appropriate viscosity is created. Other gelling agents, such as PVP (polyvinylpyrrolidone), PEO (polyethyleneoxide), or PVA (polyvinylalcohol) can also be used. Successful gels have been formulated from a HPMC powder at 2% w/w.
[0067] The concentration of an active agent in the gel may vary widely depending on the agent of interest and the desired patch dosage and planned duration of application. Generally, the concentration will range from about 0.2% to 10% (weight).
[0068]
[0069] Beginning with the fully packaged device of
[0070] Next, the first panel 36A is folded at the fold line 32 onto the second panel 36B, thereby bringing the occlusive region as at 80 of the occlusive layer 80 of the anode and cathode gel pads 60, 62 in permanent adhesive contact with the occlusive tape layer 40 of the transdermal patch 24 as shown in
[0071] Finally, the half release liner 54 is peeled from the support structure at the tab 54A bringing the fully assembled transdermal patch 170 with it. The exposed half of the patch adhesive can be applied to the treatment site and the half release liner 54 thereafter can be peeled from the transdermal patch at the tab 54B (
[0072]
[0073] The drug pack includes a flat card substrate layer 212 which is designed with spaced alignment openings 214 and 216 which register with alignment members 204 and 206 during assembly. Anode and cathode non-woven, gel-imbibed pads 218 and 220 are respectively carried on a bottom layer 222 and separated from drug pack lid 224 in the manner of embodiments previously described and illustrated in
[0074] The transdermal patch component 210 is mounted on a flat card substrate layer 228 with spaced alignment openings 230 and 232 and, as with previously described embodiments, half release liner 234. The patch assembly may be quite similar in construction to that previously described with foam layer 236 and double-sided tape 238, electrode subassembly layer 240 and overlaying tape layer 242.
[0075] At the time of use, individual components are aligned and assembled to each other using features of a component to self-align to adjacent components. In this manner, the guide element 202 may be positioned on a flat surface with the spaced alignment members 204, 206 facing up as shown in
[0076] In this stacked condition, the assembled patch is ready to be separated for placement on a patient. Separation can be accomplished by simply peeling the half release liner 234 from the card thereby separating the device from the card substrate layer 228 and bringing the fully assembled transdermal patch 250 with it as shown in
[0077] It will be appreciated that the drug pack 208 and the transdermal patch 210 are similar in construction to previously described embodiments except that the card substrate layers in this embodiment are separate flat members rather than folding connected panels. The flat card substrate layers 212, 228 include alignment openings corresponding to the members 204 and 206 on guide element 202 and they do not require a silicon or other release coating so that both sides may contain a printable clay coating material or the like.
[0078] The card layers 212, 228 may also be constructed from any suitable polymer material. The alignment members 204 and 206 of the guide element 202 are preferably thermoformed or injection molded out of a suitable polymer material also.
[0079]
[0080] Assembly and activation is similar to that of the embodiment of
[0081]
[0082] It will further be appreciated that the assembled device or patch to be applied to a user may be of any convenient size as from as small as about 1 cm2 cm to about 15 cm20 cm. The size can vary widely depending on the active agent administered and the condition to be treated.
[0083] This invention has been described herein in considerable detail in order to comply with the patent statutes and to provide those skilled in the art with the information needed to apply the novel principles and to construct and use embodiments of the example as required. However, it is to be understood that the invention can be carried out by specifically different devices and that various modifications can be accomplished without departing from the scope of the invention itself.