U.S. patent application number 10/690384 was filed with the patent office on 2004-04-29 for titratable dosage transdermal delivery system.
This patent application is currently assigned to Euro-Celtique, S.A.. Invention is credited to Wright, Curtis IV.
Application Number | 20040081685 10/690384 |
Document ID | / |
Family ID | 24870722 |
Filed Date | 2004-04-29 |
United States Patent
Application |
20040081685 |
Kind Code |
A1 |
Wright, Curtis IV |
April 29, 2004 |
Titratable dosage transdermal delivery system
Abstract
The present invention relates to a titratable dosage transdermal
delivery system for systemic delivery of a therapeutic agent or
drug. The system comprises a plurality of patch units that are
connected along one or more borders. The plurality of patch units
are divisible into units along the one or more borders having one
or more lines of separation. Each patch unit is surrounded by a
border. The therapeutic patch has at least a backing layer and a
therapeutic agent comprising layer. The dosage of therapeutic agent
delivered to a patient is proportional to the number of patch unit
applied per treatment. The system enables systemic administration
of a titratable dosage of therapeutic agent, adjustable by the
patient under the direction of a physician, through the skin or
mucosa. Moreover, the invention relates to a method of making the
titratable dosage transdermal delivery system. Furthermore, the
invention relates to a method of providing a titratable amount of
therapeutic agent to a patient using the transdermal delivery
system of the invention.
Inventors: |
Wright, Curtis IV; (Norwalk,
CT) |
Correspondence
Address: |
JONES DAY
222 EAST 41ST STREET
NEW YORK
NY
10017
US
|
Assignee: |
Euro-Celtique, S.A.
|
Family ID: |
24870722 |
Appl. No.: |
10/690384 |
Filed: |
October 20, 2003 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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10690384 |
Oct 20, 2003 |
|
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09714604 |
Nov 16, 2000 |
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6682757 |
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Current U.S.
Class: |
424/449 |
Current CPC
Class: |
A61K 31/4468 20130101;
A61P 9/10 20180101; A61P 25/04 20180101; A61F 2013/0296 20130101;
A61P 23/02 20180101; A61P 9/04 20180101; A61P 25/00 20180101; A61K
9/703 20130101; A61P 43/00 20180101; A61P 5/00 20180101; A61K
9/7084 20130101; A61P 25/18 20180101; A61K 31/485 20130101; A61P
25/08 20180101; A61K 9/7092 20130101; A61K 9/7038 20130101; A61P
29/00 20180101; A61P 23/00 20180101; A61P 3/02 20180101; A61P 31/04
20180101; A61P 3/10 20180101 |
Class at
Publication: |
424/449 |
International
Class: |
A61K 009/70 |
Claims
What is claimed:
1. A method of delivering a drug through a patient's skin
comprising: (a) providing a transdermal delivery system that
comprises a plurality of patch units, wherein each patch unit
comprises a backing layer having one or more borders, a drug layer
comprising a drug disposed on the backing layer, and an adhesive
layer, wherein the drug is a narcotic analgesic, a local
anesthetic, a sedative, a tranquilizer, or a combination thereof,
and wherein at least a portion of the adhesive layer is disposed on
the borders of the backing layer; the plurality of patch units are
connected to each other along one or more borders of the patch
units; and each patch unit is defined by one or more lines of
separation along the borders of the patch units; (b) separating at
least one patch unit from the transdermal delivery system along at
least one line of separation; and (c) applying at least one patch
unit such that the drug layer makes contact with the skin.
2. The method of claim 1 wherein the patch units are applied on the
skin of the planter foot arch, lateral ankle, palm, upper arm,
ventral forearm, dorsal forearm, back, chest, thigh, abdomen,
scalp, axilla, forehead, lower back, chest, buttocks or
scrotum.
3. The method of claim 1 wherein a portion of the adhesive layer is
disposed on the drug layer; and a cover layer is disposed on the
adhesive layer.
4. The method of claim 1 wherein the drug is fentanyl, etorphine,
buprenorphine, penzocaine, morphine, morphine derivative,
lidocaine, prilocaine, mepivacaine, pentabarbital sodium,
phenobarbital, secobarbital sodium, codeine, (a-bromoisovaleryl)
urea, carbromal, sodium phenobarbital, or a combination
thereof.
5. The method of claim 3 wherein said transdermal delivery system
further comprises a release limiting layer disposed on the drug
layer.
6. The method of claim 1 wherein the drug is encapsulated by
microcapsules.
7. The method of claim 1 wherein the drug layer comprises about
0.1-90% by weight of the drug.
8. The method of claim 1 wherein the drug layer comprises about
10-45% by weight of the drug.
9. The method of claim 1 wherein the drug layer comprises about
25-40% by weight of the drug.
10. The method of claim 1 wherein the drug layer further comprises
a softening agent, wherein the softening agent is dodecanol,
undecanol, octoanol, esters of carboxylic acids, or a combination
thereof.
11. The method of claim 1 wherein the drug layer further comprises
a permeation enhancing agent.
12. The method of claim 3 wherein the cover layer comprises a notch
so as to facilitate separation of the cover layer from the adhesive
layer.
13. The method of claim 1 wherein the transdermal delivery system
is stored in a resealable pouch.
14. The method of claim 1 wherein the lines of separation are
parallel and/or perpendicular to each other.
15. The method of claim 1 wherein the lines of separation are lines
of perforations.
16. The method of claim 1 wherein the lines of separation are
spaced at regular intervals.
17. The method of claim 1 wherein the lines of separation are about
1 cm to 6 cm apart.
18. The method of claim 1 wherein 2 to 5 patch units are connected
in series in the transdermal delivery system.
19. The method of claim 1 wherein 4 patch units are arranged in 2
rows and 2 columns in the transdermal delivery system.
20. The method of claim 1 wherein the drug layer is a reservoir
layer.
21. The method of claim 1 wherein the drug layer is a
drug-in-matrix layer.
22. The method of claim 1 wherein the drug layer is a
drug-in-adhesive layer.
23. The method of claim 1 wherein two to five patch units are
applied on the skin.
24. A method of delivering a drug through a patient's skin
comprising: (a) providing a transdermal delivery system that
comprises a plurality of patch units, wherein each patch unit
comprises a backing layer having one or more borders, a drug layer
comprising fentanyl disposed on the backing layer, and an adhesive
layer, wherein at least a portion of the adhesive layer is disposed
on the borders of the backing layer; the plurality of patch units
are connected to each other along one or more borders of the patch
units; and each patch unit is defined by one or more lines of
separation along the borders of the patch units; (b) separating at
least one patch unit from the transdermal delivery system along at
least one line of separation; and (c) applying at least one patch
unit such that the drug layer makes contact with the skin.
25. A method of delivering a drug through a patient's skin
comprising: (a) providing a transdermal delivery system that
comprises a plurality of patch units, wherein each patch unit
comprises a backing layer having one or more borders, a drug layer
comprising buprenorphine disposed on the backing layer, and an
adhesive layer, wherein at least a portion of the adhesive layer is
disposed on the borders of the backing layer; the plurality of
patch units are connected to each other along one or more borders
of the patch units; and each patch unit is defined by one or more
lines of separation along the borders of the patch units; (b)
separating at least one patch unit from the transdermal delivery
system along at least one line of separation; and (c) applying at
least one patch unit such that the drug layer makes contact with
the skin.
26. A method of delivering a narcotic analgesic through a patient's
skin comprising: (a) providing a transdermal delivery system that
comprises a plurality of patch units, wherein each patch unit
comprises a backing layer having one or more borders, a drug layer
comprising a narcotic analgesic disposed on the backing layer, and
an adhesive layer, wherein at least a portion of the adhesive layer
is disposed on the borders of the backing layer; the plurality of
patch units are connected to each other along one or more borders
of the patch units; and each patch unit is defined by one or more
lines of separation along the borders of the patch units; (b)
separating at least one patch unit from the transdermal delivery
system along at least one line of separation; and (c) applying at
least one patch unit such that the drug layer makes contact with
the skin.
27. The method of claim 26 wherein the narcotic analgesic is
fentanyl.
28. The method of claim 26 wherein the narcotic analgesic is
buprenorphine.
29. A method of adjusting the therapeutic dosage of drug delivered
through a patient's skin, the method comprising: (a) providing a
transdermal delivery system that comprises a plurality of patch
units, wherein each patch unit comprises a backing layer having one
or more borders, a drug layer comprising a drug disposed on the
backing layer, and an adhesive layer, wherein the drug is a
narcotic analgesic, a local anesthetic, a sedative, a tranquilizer,
or a combination thereof, and wherein at least a portion of the
adhesive layer is disposed on the borders of the backing layer; the
patch units are connected to each other along one or more borders
of the patch units; and each patch unit is defined by one or more
lines of separation along the borders of the patch units; (b)
separating a first number of patch units from the transdermal
delivery system along at least one line of separation; (c) applying
the first number of patch units such that the drug layer makes
contact with the skin; (d) thereafter, separating a second number
of patch units from the delivery system along at least one line of
separation, the second number of patch units being different than
or the same as the first number of patch units; and (e) applying
the second number of patch units such that the drug layer makes
contact with the skin.
30. The method of claim 29 wherein one or more patch units from the
first number of patch units are removed from the skin before
applying the second number of patch units to the skin.
31. The method of claim 29 wherein one or more patch units from the
first number of patch units remain on the skin before applying the
second number of patch units to the skin.
32. The method of claim 29 wherein the drug is fentanyl, etorphine,
buprenorphine, penzocaine, morphine, morphine derivative,
lidocaine, prilocaine, mepivacaine, pentabarbital sodium,
phenobarbital, secobarbital sodium, codeine, (a-bromoisovaleryl)
urea, carbromal, sodium phenobarbital, or a combination
thereof.
33. The method of claim 29, comprising increasing the dosage of
drug through the patient's skin, wherein the second number of patch
units is greater than the first number of patch units.
34. The method of claim 29, comprising decreasing the dosage of
drug through the patient's skin, wherein the second number of patch
units is less than the first number of patch units.
35. A method of adjusting the therapeutic dosage of drug delivered
through a patient's skin, the method comprising: (a) providing a
transdermal delivery system that comprises a plurality of patch
units, wherein each patch unit comprises a backing layer having one
or more borders, a drug layer comprising fentanyl disposed on the
backing layer, and an adhesive layer, wherein at least a portion of
the adhesive layer is disposed on the borders of the backing layer;
the patch units are connected to each other along one or more
borders of the patch units; and each patch unit is defined by one
or more lines of separation along the borders of the patch units;
(b) separating a first number of patch units from the transdermal
delivery system along at least one line of separation; (c) applying
the first number of patch units such that the drug layer makes
contact with the skin; (d) thereafter, separating a second number
of patch units from the delivery system along at least one line of
separation, the second number of patch units being different than
or the same as the first number of patch units; and (e) applying
the second number of patch units such that the drug layer makes
contact with the skin.
36. The method of claim 35 wherein one or more patch units from the
first number of patch units are removed from the skin before
applying the second number of patch units to the skin.
37. The method of claim 35 wherein one or more patch units from the
first number of patch units remain on the skin before applying the
second number of patch units to the skin.
38. The method of claim 35, comprising increasing the dosage of
fentanyl through the patient's skin, wherein the second number of
patch units is greater than the first number of patch units.
39. The method of claim 35, comprising decreasing the dosage of
fentanyl through the patient's skin, wherein the second number of
patch units is less than the first number of patch units.
40. A method of adjusting the therapeutic dosage of drug delivered
through a patient's skin, the method comprising: (a) providing a
transdermal delivery system that comprises a plurality of patch
units, wherein each patch unit comprises a backing layer having one
or more borders, a drug layer comprising buprenorphine disposed on
the backing layer, and an adhesive layer, wherein at least a
portion of the adhesive layer is disposed on the borders of the
backing layer; the patch units are connected to each other along
one or more borders of the patch units; and each patch unit is
defined by one or more lines of separation along the borders of the
patch units; (b) separating a first number of patch units from the
transdermal delivery system along at least one line of separation;
(c) applying the first number of patch units such that the drug
layer makes contact with the skin; (d) thereafter, separating a
second number of patch units from the delivery system along at
least one line of separation, the second number of patch units
being different than or the same as the first number of patch
units; and (e) applying the second number of patch units such that
the drug layer makes contact with the skin.
41. The method of claim 40 wherein one or more patch units from the
first number of patch units are removed from the skin before
applying the second number of patch units to the skin.
42. The method of claim 40 wherein one or more patch units from the
first number of patch units remain on the skin before applying the
second number of patch units to the skin.
43. The method of claim 40, comprising increasing the dosage of
buprenorphine through the patient's skin, wherein the second number
of patch units is greater than the first number of patch units.
44. The method of claim 40, comprising decreasing the dosage of
buprenorphine through the patient's skin, wherein the second number
of patch units is less than the first number of patch units.
Description
CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application is a continuation application of pending
prior U.S. patent application Ser. No. 09/714,604, filed Nov. 16,
2000, which is incorporated herein by reference in its
entirety.
FIELD OF THE INVENTION
[0002] The present invention relates generally to a transdermal
delivery system which is applied onto the skin or mucosa of a host,
for systemic delivery of a therapeutic agent. More particularly,
the invention is directed to a titratable dosage transdermal
delivery system that comprises a plurality of patch units connected
along one or more borders. The plurality of patch units are
divisible into respective units along the one or more borders
having one or more lines of separation. The dosage provided by the
transdermal delivery system is proportional to the number of units
applied by the user as determined by a physician. Each patch unit
comprises at least a backing layer and a drug layer formulated with
at least one therapeutic agent. The transdermal delivery system
enables administration of a titratable dosage of therapeutic agent
on a solid support to the skin or mucosa of a host. Furthermore,
the invention is directed to a method of making the transdermal
delivery system. Still further, the invention is directed to a
method of providing a titratable amount of therapeutic agent to a
host using the transdermal delivery system of the invention.
BACKGROUND OF THE INVENTION
[0003] One approach to sustained delivery of a therapeutic agent is
the use of transdermal delivery system such as transdermal patches.
Generally, transdermal patches contain a therapeutic agent and an
adhesive which allows the transdermal device to adhere to the skin
of a patient, allowing for the passage of the active agent from the
device through the skin of the patient. Various advantages of using
transdermal patches include constant rate of delivery of
therapeutic agent, longer duration of action (the ability of the
patch to adhere to the skin for 1, 3, 7 days or longer),
non-invasive application, improved patient compliance, and the
supply of therapeutic agent may be interrupted at any time by
tearing off the system. The importance of this means of
administration resides in the fact that therapeutic agent can be
delivered to the bloodstream without traversing the
gastrointestinal tract and avoiding a "first pass" through the
hepatic system prior to reaching the target site. This would avoid
any gastrointestinal incompatibility with the pharmaceuticals and
unwanted destruction of the pharmaceuticals by metabolism in the
gastrointestinal tract. Once the therapeutic agent has penetrated
the skin layer, it is absorbed into the blood stream where it can
exert a desired pharmacotherapeutic effect. These benefits may be
obtained without requiring a professional to administer the
therapeutic agent. Transdermal absorption minimizes inter- and
intra-patient variations regarding such incompatibilities and
metabolisms. By transdermal absorption, it is deemed possible to
provide more constant pharmaceutical concentration in the body and
to realize a greater pharmaceutical efficiency. It is possible, by
proper transdermal absorption, to provide effective dosing of
therapeutic agent.
[0004] Current pharmaceutical practice provides for transdermal
system or transdermal patch that delivers therapeutics at fixed
dosages. The rate of delivery of therapeutic agent from the patch
to the skin or mucosa of a host, known as the flux rate, is
constant and predetermined by the individual patch that is
prescribed. The economics of manufacturing and government approval
limit the availability of patches with different dosages.
Presently, a pharmacist needs to stock multiple patches each
containing various dosages of therapeutic agents. For example, a
pharmacist needs to stock five different types of transdermal
patch, each having dosage strengths such as 25, 50, 75, 100, 150
units per time (micrograms/hour). When a doctor prescribed a
certain patch having a certain dosage strength to a patient, the
patient purchases enough supply of transdermal patches having the
fixed dosage of therapeutic agent. If the prescribed amount is too
strong, the patient will have to purchase another supply of
transdermal patches having a reduced dosage of therapeutic agent.
If the prescribed amount is too weak, the patient will have to
purchase another supply of transdermal patches having an increased
dosage of therapeutic agent. In this current practice, patches that
do not provide the optimum dosage for the patient are being
wasted.
[0005] Thus, there remains a long felt, yet currently unmet need to
provide a transdermal delivery system that can deliver titratable
dosage of therapeutic agent. This titratable dosage transdermal
delivery system has the advantage of minimizing wastage of
transdermal patches that do not provide optimal dosage level of
therapeutic agent. There is also a need for a transdermal system
which allows fine control of dosage of therapeutic agent to be
delivered to a patent. The transdermal delivery system of the
present invention solves the problem by providing adjustable dosage
of therapeutic agent from a single transdermal delivery system.
This invention reduces the number of different types of transdermal
patch having various dosage strengths that need to be stocked by a
pharmacist. For example, the pharmacist mentioned above would only
need to stock two types of transdermal delivery system of the
present invention. One type has a dosage of 25 units per patch and
the second type has a dosage of 75 units per patch unit. From these
two types of patches, it is possible to deliver various dosage
strengths such as 25, 50, 75, 100, 150 units. For example, in order
to achieve a strength of 50 units, 2 patches of the 25 unit dosage
per patch unit may be used. To achieve a strength of 100 units, 4
patches of the same type of patch may be used. To achieve a
strength of 150 units, 2 patches of the 75 unit dosage per patch
unit may be used. Instead of stocking five different kinds of
patches containing different dosages, only two different kinds of
patches need to be stocked.
SUMMARY OF THE INVENTION
[0006] The present invention is based upon the observation of the
inventor that an optimal dosage of therapeutic agent may be
delivered to the skin or mucosa of a host, by means of a titratable
dosage transdermal delivery system. The present system addresses
three shortcomings of the current technology. First, with the
advent of transdermal patch, self-administration by a patient is
generally involved. Patient compliance with application
instructions takes on great importance. The present system provides
an easy method of adjusting the dosage of therapeutic agent by the
patient through the use of the system of the invention by following
simple instructions from the physician. Second, the present system
reduces the number of therapeutic patches with different dosages
that need to be stocked by a pharmacist. Third, the present system
reduces wastage of transdermal patches that have suboptimal dosage
of therapeutic agent.
[0007] It is an object of this invention to provide a titratable
dosage transdermal delivery system for the systemic delivery of one
or more therapeutic agents to the skin or mucosa of a host.
[0008] The system comprises a plurality of patch units connected
along one or more borders. Each patch unit comprises: a backing
layer having a top surface and a bottom surface; a drug layer
disposed on the top surface of the backing layer; and a means for
adhering the patch unit onto the skin or mucosa of a host layer,
where each patch unit is defined by one or more lines of separation
on the border.
[0009] In one embodiment, the system comprises a plurality of patch
units connected along one or more borders. Each patch unit
comprises: (a) a backing layer having a top surface and a bottom
surface; (b) a drug layer with matrix layer disposed on the top
surface of the backing layer; and (c) an adhesive layer disposed on
the drug layer with matrix layer, wherein each patch unit is
defined by one or more lines of separation on the border.
[0010] In one embodiment, the system comprises a plurality of patch
units connected along one or more borders. Each patch unit
comprises: (a) a backing layer having a top surface and a bottom
surface; (b) a drug layer with matrix layer disposed on the top
surface of the backing layer; (c) an adhesive layer disposed on the
drug layer with matrix layer; and (d) a cover layer disposed on the
adhesive layer, wherein each patch unit is defined by one or more
lines of separation on the border.
[0011] In another embodiment, the transdermal delivery system
comprises a plurality of patch units connected along one or more
borders. Each patch unit comprises: a backing layer having a top
surface and a bottom surface; a drug and adhesive layer disposed on
the top surface of the backing layer; and a cover layer disposed on
the adhesive layer, wherein each patch unit is defined by one or
more lines of separation on the border.
[0012] Moreover, it is an object of the present invention to
provide a transdermal delivery system which comprises a plurality
of patch units connected along one or more borders. Each patch unit
comprises: a backing layer having a top surface and a bottom
surface; a drug and adhesive layer disposed on the top surface of
the backing layer; a release limiting layer disposed on the drug
and adhesive layer; a second drug and adhesive layer disposed on
the release limiting layer; and a cover layer disposed on the
release limiting layer, wherein each patch unit is defined by one
or more lines of separation on the border.
[0013] In addition, it is an object of the present invention to
provide a method of making the transdermal delivery system which
delivers a titratable dosage of drugs to a patient. The method
comprises forming a backing layer with top and bottom surfaces,
which backing layer is divided into more than one unit at one or
more lines of separation. A drug-in-matrix layer is disposed on the
top surface of each unit of the backing layer, leaving a border on
all sides of the backing layer. An adhesive layer is disposed on
the drug-in-matrix layer and the border of the backing layer. A
cover layer is then disposed on top of the adhesive layer.
[0014] Still further, in one embodiment, the method comprises
forming a plurality of reservoir compartments within an enclosure
defined by the raised wall directly on a backing layer. Each
reservoir compartment is surrounded by a border having a surface.
One or more lines of separation are formed on the border dividing
the plurality of the reservoir compartments into separate units. A
drug layer is disposed into each of the reservoir compartments. An
adhesive layer is then disposed on top of the drug layer and on the
surface of the border. A cover layer is then disposed on the
adhesive layer which covers the surface of the border and the
adhesive layer.
[0015] Furthermore, it is an object of the present invention to
provide a method of making the transdermal delivery system which
delivers a titratable dosage of drugs to a patient. The method
comprises forming a backing layer with top and bottom surfaces,
which backing layer is divided into more than one units at one or
more lines of separation. A drug-in-adhesive layer is disposed on
the top surface of each unit of the backing layer, leaving a border
on all sides of the backing layer. A cover layer is disposed on top
of the adhesive layer.
[0016] Moreover, in one embodiment, the method comprises the steps
of forming a backing layer with top and bottom surfaces, which
backing layer is divided into more than one units at one or more
lines of separation. A drug-in-adhesive layer is disposed on the
top surface of each unit of the backing layer, leaving a border on
all sides of the backing layer. A semi-permeable membrane is
disposed on the backing film so as to hold the drug-in-adhesive
within the border. A second drug-in-adhesive layer is disposed on
the semi-permeable membrane. The border is covered with an
adhesive. A cover layer is disposed on the drug-in-adhesive
layer.
[0017] Finally, it is an object of the present invention to provide
a method of delivering a therapeutic agent through the skin or
mucosa of a patient. The method comprises providing a transdermal
delivery system; separating a prescribed number of units of patches
from the transdermal delivery system along at least one line of
separation; and removing the cover layer exposing the adhesive
layer and applying it on the skin or mucosa.
BRIEF DESCRIPTION OF THE DRAWINGS
[0018] The various advantages and novel features of this invention
will be more apparent from a reading of the Detailed Description of
the Present Invention in conjunction with the accompanying drawings
in which like reference numerals refer to like parts.
[0019] FIG. 1 illustrates a schematic diagram showing an embodiment
of the transdermal delivery system of the invention.
[0020] FIG. 2 illustrates a schematic diagram showing an embodiment
of the transdermal delivery system of the invention.
[0021] FIG. 3a illustrates a schematic diagram showing a
cross-section of a matrix type transdermal delivery system of the
invention.
[0022] FIG. 3b illustrates a schematic diagram showing a
cross-section of a reservoir type transdermal delivery system of
the invention.
[0023] FIG. 3c illustrates a schematic diagram showing a
cross-section of a monolithic drug-in-adhesive type transdermal
delivery system of the invention.
[0024] FIG. 3d illustrates a schematic diagram showing a
cross-section of a multilaminate drug-in-adhesive type transdermal
delivery system of the invention.
DETAILED DESCRIPTION OF THE INVENTION
Transdermal Delivery System of the Invention
[0025] In general, this invention is directed to a divisible
transdermal delivery system which can deliver a titratable dosage
of therapeutic agent to the skin or mucosa of a patient. The system
of the present invention comprises a plurality of patch units
joined together along one or more borders. In other words, the
system comprises divisible units of therapeutic patch, thus
delivering a controlled amount of therapeutic agent proportional to
the number of patch units as desired. As illustrated in FIG. 1, the
titratable transdermal delivery system 10 comprises a plurality of
units. In this embodiment, there are four (4) units 20 in the
system 10 arranged in 2 columns with 2 rows (i.e. 2.times.2
format). Each unit 20 comprises four borders 30 surrounding a
therapeutic delivery zone 40. The plurality of therapeutic patches
are divisible along the border. The border may be perforated to
form a line of separation which facilitates division of the
therapeutic patches into one or more units comprising one or more
doses of therapeutic agent. In this embodiment, each unit 20 has
two lines of separation 50.
[0026] In another embodiment as illustrated in FIG. 2, the
titratable transdermal delivery system 10 comprises a plurality of
therapeutic patch units arranged in a single row. Here, there are
five (5) units 20 in the system 10. Each unit 20 comprises four
borders 30 surrounding a therapeutic delivery zone 40. Similar to
the embodiment in FIG. 1, the plurality of therapeutic patches are
divisible along the border. In this embodiment, the two (2) units
20 at the ends of the transdermal delivery system 10 have one line
of separation 50 whereas the three (3) units at the middle of the
transdermal delivery system have two lines of separation.
[0027] A patch suitable for use with the invention should contain
at least: (1) a backing layer and (2) a therapeutic agent
comprising layer. Each patch unit is surrounded by a border which
is free of therapeutic agents. The patch may comprise an adhesive
means for securing to the surface of the skin or mucosa. In a
preferred embodiment, a cover layer is also present to protect the
therapeutic agent comprising layer. In another preferred
embodiment, the cover layer comprises a hermetic peelable seal
which may be formed by heat sealing or an adhesive. In another
preferred embodiment, the cover layer has a notch which provides
for easy separation of the cover layer from the patch.
[0028] Preferred patches that are suitable for use in this
invention include, for example, (1) the matrix type patch; (2) the
reservoir type patch; (3) the monolithic drug-in-adhesive type
patch; and (4) the multi-laminate drug-in-adhesive type patch
(Ghosh, T. K.; Pfister, W. R.; Yum, S. I. Transdermal and Topical
Drug Delivery Systems, Interpharm Press, Inc. p. 249-297). These
patches are well known in the art. Other patches may be useful for
the present invention as determined by one of skill in the art.
[0029] For practice of the invention, the matrix type patches are
the most preferred.
Matrix Type Transdermal System
[0030] FIG. 3a illustrates an embodiment of the system of the
invention which utilizes a matrix patch. The matrix patch comprises
a backing layer 60 which comprises two opposing surfaces. One of
the surface is in contact with a drug with matrix layer 70, which
is a matrix layer containing a therapeutic agent, and an adhesive
layer 80. The drug with matrix layer 70 does not cover the entire
area of the patch unit but are confined at the drug delivery zone
40 as shown in FIGS. 1 and 2, leaving a border 30 surrounding the
drug delivery zone 40. A line of separation 50 divides the borders
30 of adjacent patch units 20. The line of separation facilitates
the division of the system into separate units. The line of
separation may be formed by perforations or weaknesses created in
the backing layer.
[0031] In a preferred embodiment, a release liner (not shown) is
disposed on the adhesive layer 80 or the drug with matrix layer 70.
In some cases, it may be necessary to include an impermeable layer
(not shown) on the surface of the backing layer 60 that is in
contact with the drug with matrix layer 70 to minimize drug
migration into the backing film (e.g., U.S. Pat. No. 4,336,243).
The matrix containing the therapeutic agent is held against the
skin by the adhesive layer 80. Adhesives may also be present on the
surface of the borders 30 to provide further adhesion for the patch
to the skin.
[0032] The backing layer may be formed of woven or braided fibers
or wires, membranes, porous or fibrous scaffolds made of a polymer.
The polymer(s) useful for forming the therapeutic patch should be
ones that are biocompatible and avoid irritation to the skin or
mucosa. The backing layer can be made of a pharmaceutically
acceptable material which is impermeable to the therapeutic agent
used. The backing layer preferably serves as a protective cover for
the therapeutic agent and may also provide a support function.
Examples of materials suitable for making the backing layer are
synthetic polymers like films of high and low density polyethylene,
polypropylene, polyvinylchloride, polyurethane, polyesters such as
poly(ethylene phthalate), metal foils, metal foil laminates of
suitable polymer films, textile fabrics. Other examples for backing
materials are from natural materials like cotton, wool, etc.
Preferably, the materials used for the backing layer are laminates
of such polymer films with a metal foil such as aluminum foil. One
preferred type of backing material is nonwoven urethane material,
such as described in, for example, U.S. Pat. No. 5,230,701 to Meyer
et al. More preferably the backing films are occlusive and
comprised of a polyolefin oil. Occlusive backing films, such as
synthetic polyesters, result in hydration of the outer layers of
the stratum corneum while non-occlusive backings allow the area to
breath (i.e., promote water vapor transmission from the skin
surface). The backing layer can be any appropriate thickness which
will provide the desired protective and support functions. A
suitable thickness will be from about 10 to about 200 microns.
Desirable materials and thickness will be apparent to the skilled
artisan.
[0033] Generally, the matrix layer is formed from biologically
acceptable polymers capable of forming thin walls or coatings
through which pharmaceuticals can pass at a controlled rate.
Examples of suitable matrix materials include but are not limited
to lipophilic polymers, such as polydimethylsiloxane, and
hydrophilic polymers like polyvinylpyrrolidone, polyvinyl alcohol,
hydrogels based on gelatin, or polyvinylpyrrolidone/polyethylene
oxide mixtures. A non-limiting list of exemplary materials for
inclusion in the polymer matrix includes polyethylene,
polypropylene, ethylene/propylene copolymers,
ethylene/ethylacrylate copolymers, ethylenevinyl acetate
copolymers, silicones, rubber, rubber-like synthetic homo-, co- or
block polymers, polyacrylic esters and the copolymers thereof,
polyurethanes, polyisobutylene, chlorinated polyethylene,
polyvinylchloride, vinyl chloride-vinyl acetate copolymer,
polymethacrylate polymer (hydrogel), polyvinylidene chloride,
poly(ethylene terephthalate), ethylene-vinyl alcohol copolymer,
ethylene-vinyloxyethanol copolymer, silicones including silicone
copolymers such as polysiloxane-polymethacrylate copolymers,
cellulose polymers (e.g., ethyl cellulose, and cellulose esters),
polycarbonates, polytetrafluoroethylene and mixtures thereof.
[0034] Preferred materials for inclusion in the matrix layer can be
any silicone elastomers of the general polydimethylsiloxane
structures, e.g., silicone polymers. Preferred are cross-linked
silicone polymers that are pharmaceutically acceptable. Other
preferred materials for inclusion in the polymer matrix layer
include: silicone polymers that are cross-linkable copolymers
having dimethyl and/or dimethylvinyl siloxane units which can be
crosslinked using a suitable peroxide catalyst. Also preferred are
those polymers consisting of block copolymers based on styrene and
1,3-dienes (particularly linear styrene-isoprene-block copolymers
of styrene-butadiene-block copolymers), polyisobutylenes, polymers
based on acrylate and/or methacrylate.
[0035] The polymer matrix layer may optionally include a
pharmaceutically acceptable crosslinking agent. Suitable
crosslinking agents include, e.g., tetrapropoxy silane.
[0036] An adhesive layer may be used to affix the transdermal patch
to the skin of the patient for a desired period of administration,
e.g., about 5 to about 8 days. If the adhesive layer of the
transdermal patch fails to provide adhesion for the desired period
of time, it is possible to maintain contact between the transdermal
patch with the skin by, for instance, affixing the transdermal
patch to the skin of the patient with an adhesive tape, e.g.,
surgical tape. It is not critical for purposes of the present
invention whether adhesion of the transdermal patch to the skin of
the patient is achieved solely by the adhesive layer of the
transdermal patch or in connection with a peripheral adhesive
source, such as surgical tape, provided that the transdermal patch
is adhered to the patient's skin for the requisite administration
period.
[0037] The adhesive layer is preferably an active ingredient
permeable adhesive layer that joins the device to the skin or
mucosa of the host. It is also preferably dermatologically
acceptable. Each active ingredient permeable adhesive layer is
preferably a pressure-sensitive adhesive. Any of the well-known,
dermatologically acceptable, pressure-sensitive adhesives which
permit drug migration therethrough can be used in the present
invention.
[0038] Some suitable permeable adhesives include acrylic or
methacrylic resins such as polymers of alcohol esters of acrylic or
methacrylic acids and alcohols such as n-butanol, isopentanol,
2-methylbutanol, 1-methylbutanol, 1-methylpentanol,
2-methylpentanol, 3-methylpentanol, 2-ethyl-butanol, isooctanol,
n-decanol, or n-dodecanol, alone or copolymerized with
ethylenically unsaturated monomers such as acrylic acid,
methacrylic acid, acrylamide, methacrylamides, N-alkoxymethyl
acrylamides, N-alkoxymethyl methacrylamides, N-t-butylacrylamide,
itaconic acid, vinyl acetate, N-branched alkyl maleamic acids
wherein the alkyl group has 10-24 carbon atoms, glycol diacrylates,
or mixtures of these monomers; polyurethane elastomers; vinyl
polymers such as polyvinyl alcohol, polyvinyl ethers, polyvinyl
pyrrolidone, and polyvinyl acetate; urea formaldehyde resins;
phenol formaldehyde resins, resorcinol formaldehyde resins;
cellulose derivatives such as ethylcellulose, methylcellulose,
nitrocellulose, cellulose acetate butyrate and
carboxymethylcellulose; and natural gums such as guar, acacia,
pectina, starch, destria, gelatin, casein, etc. Other suitable
pressure-sensitive adhesives include polyisobutylene
pressure-sensitive adhesives, rubber pressure-sensitive adhesives
and silicone pressure-sensitive adhesives. The adhesives may also
be compounded with tackifiers and stabilizers as is well-known in
the art. Any of the well known dermatologically acceptable
hypoallergenic pressure-sensitive adhesives can be used in
practicing this invention. Exemplary adhesives include acrylic or
methacrylic resins such as polymers of esters of acrylic or
methacrylic acid with alcohols such as n-butanol, n-pentanol,
isopentanol, 2-methyl butanol, 1-methyl butanol, 1-methyl penanol,
2-methyl penanol, 3-methyl pentanol, 2-ethyl butanol, isooctanol,
n-decanol, or n-dodecanol, alone or copolymerized with
ethylenically unsaturated monomers such as acrylic acid,
methacrylic acid, acrylamide, methacrylamide, N-alkoxymethyl
acrylamides, N-alkoxymethyl methacrylamides,
N-tert.butylacrylamide, itaconic acid, vinylacetate, N-branched
alkyl maleamic acids wherein the alkyl group has 10 to 24 carbon
atoms, glycol diacrylates, or mixtures of these; natural or
synthetic rubbers such as styrenebutadiene, butylether, neoprene,
polyisobutylene, polybutadiene, and polyisoprene; polyvinylacetate;
ureaformaldehyde resins; phenolformaldehyde resins; resorcinol
formaldehyde resins, cellulose derivatives such as ethyl cellulose,
methyl cellulose, nitrocellulose, cellulose acetatebutyrate, and
carboxymethyl cellulose; and natural gums such as guar, acacia,
pectins, starch, dextrin, albumin, gelatin, casein, etc. The
adhesives may be compounded with tackifiers and stabilizers as is
well known in the art.
[0039] Adhesives that are preferred for their active agent
permeability include acrylic copolymer adhesives such as Avery
Chemical Company's AS-351 HSX, preferably at a coating weight of
between 25 and 35 g/m.sup.2. This pressure-sensitive adhesive is a
cross-linkable polymer which provides a permanently tacky film
having a total solids content of about 52%, Brookfield viscosity
(LVT/Spindle No. 4/12 RPM @ 25.degree. C.) of from about 15,000 to
25,000 cps. at a weight per gallon of about 7.4 lbs. It can also be
diluted with hexane or toluene to a desired solids and/or viscosity
range, particularly for use in conventional coating equipment.
[0040] In preferred embodiments, the transdermal patch includes a
removable protective cover layer. The protective cover layer is
removed prior to application, and consists of the materials used
for the backing layer described above provided that they are
rendered removable, for example, by a silicone treatment. Other
removable protective cover layers, for example, are
polyletra-fluoroethylene, treated paper, allophane, polyvinyl
chloride, and the like. Generally, the removable protective layer
is in contact with the adhesive layer and provides a convenient
means of maintaining the integrity of the adhesive layer until the
desired time of application.
[0041] In another preferred embodiment, the transdermal delivery
system comprises a plurality of therapeutic patches which are
stored in a resealable pouch.
Reservoir Type Transdermal System
[0042] FIG. 3b illustrates an embodiment of the system of the
present invention which uses a reservoir type patch. The reservoir
type patch design is characterized by a backing layer 60 and a
reservoir compartment 90 containing a drug layer 75 preferably, in
the form of a solution or suspension, that is separated from the
skin by a semipermeable membrane (not shown) (e.g., U.S. Pat. No.
4,615,699). The reservoir compartment 90 is a continuation of
backing layer 60. The backing layer 60 is molded and formed having
sidewalls 35 that defines the protected volume of the reservoir
compartment 90. The amount of drug that may be placed within the
reservoir compartment 90 is defined by the dimensions of the
reservoir compartment 90 and the height of the sidewalls 35. The
backing layer 60 has an upper surface 65, a side wall 35, defining
a drug delivery zone 40 as shown in FIGS. 1 and 2, and a reservoir
compartment 90 extending throughout the entire drug delivery zone
40. An adhesive layer 80 is disposed on top of the drug layer 75
and on the surface of the backing layer 65 which extends around the
reservoir's boundaries, forming the border 30, so as to provide a
seal with the skin and hold the reservoir adjacent to the skin or
mucosa where a desirable number of unit patches of the transdermal
system may be applied. At the border, a line of separation 50
extends throughout the raised walls 100 that are formed by the
backing layer 60.
[0043] In one embodiment, the drug delivery zone 40 is rectangular.
Alternatively, the drug delivery zone 40 may be a variety of
shapes, such as, but not limited to, oval, circular, elliptical,
triangular, rectangular, hexagonal. In a preferred embodiment, the
drug delivery zone 40 has the same shape and therefore concentric
to a patch unit of the transdermal system.
[0044] Other pharmaceutically acceptable compounds which may be
included in the reservoir or matrix include: solvents, for example
alcohols such as isopropanol; permeation enhancing agents such as
those described infra; and viscosity agents, such as cellulose
derivatives, natural or synthetic gums, such as guar gum, and the
like.
[0045] Certain preferred transdermal delivery systems also include
a softening agent in the reservoir or matrix. Suitable softening
agents include higher alcohols such as dodecanol, undecanol,
octanol, esters of carboxylic acids, wherein the alcohol component
may also be a polyethoxylated alcohol, diesters of dicarboxylic
acids, such as di-n-butyladiapate, and triglycerides particularly
medium-chain triglycerides of the caprylic/capric acids or coconut
oil, have proved to be particularly suitable. Further examples of
suitable softeners are multivalent alcohols, for example, levulinic
acid, cocprylic acids glycerol and 1,2-propanediol which can also
be etherified by polyethylene glycols.
Monolithic Drug-In-Adhesive Transdermal System
[0046] FIG. 3c illustrates an embodiment of the system of the
present invention that uses a monolithic drug-in-adhesive patch.
The monolithic drug-in-adhesive patch design is characterized by
the inclusion of the therapeutic agent formulation in the skin
contacting adhesive layer forming the drug-in-adhesive layer 100, a
backing layer 60 and preferably, a release liner (not shown). The
adhesive releases the therapeutic agent and also adheres the patch
to the skin. The drug-in-adhesive system does not require a
separate adhesive layer and thus the patch thickness is minimized
(e.g., U.S. Pat. No. 4,751,087). Therefore, drug-in-adhesive type
patches are thin and comfortable. As illustrated in FIGS. 1 and 2,
each unit of the transdermal system comprises one or more borders
made of the backing layer surrounding a drug delivery zone 40. The
drug-in-adhesive layer 100 does not cover the entire area of the
unit of the patch but are confined at the drug delivery zone 40 as
shown in FIGS. 1 and 2, leaving a border 30 surrounding the drug
delivery zone 40. The border 30 is covered with an adhesive to
further secure the unit of the therapeutic patch onto the skin. As
in any patch designs, the plurality of therapeutic patches are
divisible along the border. The border may be perforated to form a
line of separation 50 which facilitates division of the therapeutic
patches into one or more patch units comprising one or more doses
of therapeutic agent or drug respectively.
Multilaminate Drug-In-Adhesive Transdermal System
[0047] FIG. 3d illustrates an embodiment of the system of the
present invention that utilizes a multi-laminate drug-in-adhesive
patch. The multi-laminate drug-in-adhesive patch design further
incorporates additional semi-permeable membrane 200 between two or
more distinct drug-in-adhesive layers 100 under a single backing
layer 60 (Peterson, T. A. and Dreyer, S. J. Proceed. Intern. Symp.
Control. Rel. Bioact. Mater. 21: 477-478). Each layer of the
drug-in-adhesive layer 100 or the semi-permeable membrane 200 does
not cover the entire area of the patch unit but are confined at the
drug delivery zone as shown in FIGS. 1 and 2, leaving a border 30
surrounding the drug delivery zone. The edges 150 of each of the
semi-permeable membrane 200 are secured to the backing film 60 so
as to hold the drug-in-adhesive layer in place. The border 30 is
covered with an adhesive to further secure the therapeutic patch
unit onto the skin. As in any patch designs, the plurality of
therapeutic patches are divisible along the border. The border may
be perforated to form a line of separation 50 which facilitates
division of the therapeutic patches into one or more units
comprising one or more doses of therapeutic agent or drug
respectively.
[0048] In one embodiment, a release limiting layer may be used with
any patch designs especially the reservoir or multi-laminate patch,
including thin non-porous ethylene vinyl acetate films or thin
microporous films of polyethylene employed in microlaminate solid
state reservoir patches. Suitable release limiting layer include
but are not limited to occlusive, opaque, or clear polyester films
with a thin coating of pressure sensitive release liner (e.g.,
silicone-fluorsilicone, and perfluorcarbon based polymers). The
release limiting layer materials of this invention, which may or
may not be rate controlling as desired, are known in the art. The
release limiting layers are commercially available and can be made
by a multitude of different methods, as described in R. E. Kesting,
Synthetic Polymer Membranes, McGraw Hill, Chapters 4 and 5, 1971;
J. D. Ferry, Ultrafiltration Membranes, Chemical Review, Vol. 18,
Page 373, 1934. In order to obtain the most advantageous results,
the materials should be formed into structures with the desired
morphology in accordance with methods known to those skilled in the
art to achieve the desired release rate of drug. Additionally, the
material must have the appropriate chemical resistance to the drug
used and be non-toxic when used as an element of the patch of the
invention. Materials useful in forming a rate controlling limiting
layer used in this invention include, but are not limited to the
following: Polycarbonates, i.e., linear polyesters of carbonic
acids in which carbonate groups recur in the polymer chain, by
phosgenation of a dihydroxy aromatic such as bisphenol A. Such
material are sold under the trade designation Lexan by the General
Electric Company. Polyvinylchlorides; one such material is sold
under the trade designation Geon 121 by B. G. Goodrich Chemical
Company. Polyamides such as polyhexamethylene adipamide and other
such polyamides popularly known as "nylon". Modacrylic copolymers,
such as that sold under the trade designation DYNEL are formed of
polyvinylchloride (60 percent) and acrylonitrile (40 percent),
styrene-acrylic acid copolymers, and the like. Polysulfones such as
those of the type characterized by diphenylene sulfone groups in
the linear chain thereof are useful. Such materials are available
from Union Carbide Corporation under the trade designation P-1700.
Halogenated polymers such as polyvinylidene fluoride sold under the
trade designation Kynar by Pennsalt Chemical Corporation,
polyvinylfluoride sold under the trade name Tedlar by E. I. DuPont
de Nemours & Co., and the polyfluorohalocarbon sold under the
trade name Aclar by Allied Chemical Corporation. Polychlorethers
such as that sold under the trade name Penton by Hercules
Incorporated, and other such thermoplastic polyethers. Acetal
polymers such as the polyformaldehyde sold under the trade name
Delrin by E. I. DuPont de Nemours & Co., and the like. Acrylic
resins such as polyacrylonitrile polymethyl methacrylate, poly
n-butyl methacrylate and the like. Other polymers such as
polyurethanes, polyimides, polybenzimidazoles, polyvinyl acetate,
aromatic and aliphatic, polyethers, cellulose esters, e.g.,
cellulose triacetate; cellulose; collodion (cellulose nitrate with
11% nitrogen); epoxy resins; olefins, e.g., polyethylene
polypropylene; porous rubber; cross linked polyethylene oxide;
cross-linked polyvinylpyrrolidone; cross-linked polyvinyl alcohol;
polyelectrolyte structures formed of two ionically associated
polymers of the type as set forth in U.S. Pat. Nos. 3,549,016 and
3,546,141; derivatives of polystyrene such as polysodium
styrenesulfonate and polyvinylbenzyltrimethyl-ammonium chloride;
polyhydroxyethylmethacrylate; polyisobutylvinyl ether, and the
like, may also be utilized. A large number of copolymers which can
be formed by reacting various proportions of monomers from the
aforesaid said list of polymers are also useful for preparing rate
controlling limiting layer utilized in the invention.
[0049] The rate controlling release limiting layer can have varying
thickness depending upon the nature of the membrane, its porosity
and the number of membranes used in combination. Typically, a
thickness of from 20 to 200 microns is employed.
Applicable Therapeutic Agents
[0050] The applicable therapeutic agents which can be placed on the
transdermal patch can be any therapeutic substances or drugs. The
therapeutic agent can be of various physical states, e.g.,
molecular distribution, crystal forms or cluster forms. A
therapeutic agent may be encapsulated by liposomes. Liposome
comprising therapeutic agent useful in the present invention may be
prepared in a number of ways known in the art. For example,
microencapsulation techniques for the preparation of microcapsules
having a wall or membrane of polymeric material are described in
literature such as "Microencapsulation and Related Drug Processes"
by P. D. Deasy, Marcel Dekker Inc. New York (1984).
[0051] In practicing this invention one can employ any systemically
active drug which may be absorbed by the body surface to which the
transdermal patch is applied, consistent with their known dosages
and uses. Of course, the amount of drug necessary to obtain the
desired therapeutic effect will vary depending on the particular
drug used. Suitable systemic drugs for administration by the
claimed system include those useful in treating emesis and nausea
as described in U.S. Pat. No. 4,031,894, e.g., preferably,
scopolamine. Other suitable systemic drugs are disclosed in U.S.
Pat. No. 3,996,934 and include, without limitation, anti-microbial
agents such as penicillin, tetracycline, oxytetracycline,
chlortetracycline, chloramphenicol, and sulfonamides; potent
narcotics and analgesics such as fentanyl and etorphine; and local
anaesthetics such as buprenorphine, penzocaine, morphine and
morphine derivatives, lidocaine, prilocaine, mepivacaine or
non-steroidal antirheumatics/anti-inflammatories such as
indometnacin, diclofenac or etopenamate; sedatives such as
pentabarbital sodium, phenobarbital, secobarbital sodium, codeine,
(a-bromoisovaleryl) urea, carbromal, and sodium phenobarbital,
psychis energizers such a 3-(2-aminopropyl) indole acetate and
3-(2-aminobutyl) indole acetate; tranquilizers such as reserpine,
chlorpromazine hydrochloride, and thiopropazate hydrochloride;
hormones such as adrenocorticosteroids, for example
6-.alpha.-methylprednisolone; androgenic steroids, for example,
methyltestosterone, and fluoxymesterone; estrogenic steroids, for
example estrone, 17-.beta.-estradiol and ethinyl estradiol;
progesterone, and norethindrone; and thyroxine; antipyretics such
as aspirin, salicylamide, and sodium salicylate; morphine and other
narcotic analgesics; anti-diabetics, e.g., insulin; cardiovascular
agents, e.g. nitroglycerin, and cardiac glycosides such as
digitoxin, digoxin, ouabain; anti-spasmodics such as atropine,
methscopolamine bromide, methscopolamine bromide with
phenobarbital; anti-malarials such as the 4-aminoquinolines,
9-amino-quinolines, and pyrimethamine; and nutritional agents such
as vitamins, essential amino acids, and essential fats.
[0052] Additionally, in practicing this invention one can employ a
wide variety of topically active drugs consistent with their known
dosages and uses. Suitable drugs include, without limitation:
antiperspirants, e.g., aluminum chloride; deodorants, e.g.,
hexachloraphene, methylbenzethonium chloride; astringents, e.g.,
tannic acid; irritants, e.g., methyl salicylate, camphor,
cantharid; keratolytics, e.g., benzoic acid, salicylic acid,
resorcinol, iodochlorhydroxyquin; antifungal agents, such as
tolnaftate, griseofulvin, nystatin and amphotericin;
anti-inflammatory agents, such as corticosteroids, e.g.,
hydrocortisone, hydrocortisone acetate, prednisolone,
methylprednisolone, triamoinolone acetonide, fludrocortisone,
flurandrenolone, flumethasone, dexamethasone sodium phosphate,
bethamethasone, desamethasone sodium phosphate, bethamethasone
valerate, fluocinolone acetonide; fluorometholone; and pramoxine
HCl; anti-neoplastic agents, e.g. methotrexate, and antibacterial
agents, such a bacitracin, neomycin, erythromycin, tetracycline
HCl, chlortetracycline HCl, chloramphenicol, oxytetracycline,
polymyxin B, nitrofuraxone,
mafenide(alpha.-amino-p-toluenesulfonamide), hexachlorophene,
benzalkonium chloride, cetalkonium chloride, methylbenzethonium
chloride, and neomycin sulfate.
[0053] It will be appreciated, with regard to the aforesaid list of
drugs the characterization of the drug as either "systemically or
topically" active is for classification purposes, a given drug can
be both systemically and topically active depending upon its manner
of use.
[0054] Drugs employed to assist in treating problems associated
with cardiac dilation may be a suitable therapeutic agent for use
in the present invention. For example, digoxin
angiotensin-converting enzyme, ACE inhibitors, such as captopril
and enalopril, may be used.
[0055] Other suitable drugs include the coronary vasodilators
described in U.S. Pat. No. 3,742,951 such as compounds having
nitrate moiety. Some suitable coronary vasodilators include organic
and inorganic nitrates such as amyl nitrate, nitroglycerin
(glyceryl trinitrate), sodium nitrate, erythrityl tetranitrate,
pentaerythritol tetranitrate, isosorbide dinitrate, mannitol
hexanitrate, trolnitrate phosphate (triethanolamine biphosphate),
and the like. Nitroglycerine is a preferred coronary vasodilator.
Also suitable are the beta adrenegic blocking drugs such as
propanolol.
[0056] When practicing the invention, antifungal agents such as
ciclopirox, chloroxylenol, triacetin, sulconazole, nystatin,
undecylenic acid, tolnaftate, miconizole, clotrimazole,
oxiconazole, griseofulvin, econazole, ketoconozole, and
amphotericin B may be incorporated. Antibiotic agents such as
mupirocin, erythromycin, clindamycin, gentamicin, polymyxin,
bacitracin, silver sulfadiazine, and the like may also be used.
Antiseptic agents such as iodine, Povidine-iodine, benzalkonium
chloride, benzoic acid, chlorhexidine, nitrofuraxone, benzoyl
peroxide, hydrogen peroxide, hexachlorophene, phenol, resorcinol,
and cetylpyridinium chloride likewise could be incorporated into
the topical drug formulation or the patch. Furthermore,
anti-inflammatories such as hydrocortisone, prednisone,
triamcilolone, betamethasone, dexamethasone, and the like may be
incorporated.
[0057] In addition to the aforementioned drugs, simple
pharmacologically acceptable derivatives of the drugs, such as
ethers, esters, amides, acetals, salts, etc., or formulations of
these drugs, having the desired polymeric permeability or transport
or transport properties can be prepared and used in practicing the
invention. Drugs mentioned above can be used along or in
combination with others and each other.
[0058] The above drugs and other drugs can be present in the
therapeutic patch of the invention alone or in combination form
with pharmaceutical carriers. The pharmaceutical carriers
acceptable for the purpose of this invention are the known in the
art carriers that do not adversely affect the drug, the host, or
the material comprising the transdermal delivery system. Suitable
pharmaceutical carriers include sterile water; saline, dextrose;
dextrose in water or saline, condensation products of castor oil
and ethylene oxide combining about 30 to 35 moles of ethylene oxide
per mole of castor oil; liquid glyceryl triester of a lower
molecular weight fatty acid; lower alkanols, oils such as corn oil,
peanut oil, sesame oil and the like, hydrocarbons such as mineral
oils and silicones, with emulsifiers such as mono- or di-glyceride
of a fatty acid, or a phosphatide, e.g., lecithin, and the like;
glycols; polyalkylene glycols; aqueous media in the presence of a
suspending agent, for example, sodium carboxymethylcellulose;
sodium alginate; polyvinyl pyrrolidone; and the like, alone, or
with suitable dispersing agents such as lecithin; polyoxyethylene
stearate; and the like. The carrier may also contain adjuvants such
as preserving, stabilizing, wetting, emulsifying agents, and the
like.
[0059] A great number of systemically active drugs have been found
to be suitable for administration via the transdermal route.
Certain pharmaceuticals are absorbed to a degree through the skin.
This is referred to as transdermal pharmaceutical absorption. It
has been found that the transdermal absorption rates of certain
pharmaceuticals can be increased by use of absorption promoting
compounds (also referred to as skin permeation enhances) with the
pharmaceutical to be absorbed.
[0060] Penetration enhancers can be included in the drug
formulation or patch, to optimize delivery into and through the
skin. Ghosh, T. K. et al. 1993, Pharm. Tech. 17(3):72-98; Ghosh, T.
K. et al. 1993, Pharm. Tech. 17(4):62-89; Ghosh, T. K. et al.,
1993, Pharm. Tech. 17(5):68-76. Permeation enhancing agents are
compounds which promote penetration and/or absorption of the
therapeutic agent into the blood stream of the patient. The
penetration enhancer should be pharmacologically inert, non-toxic,
and non-allergenic, have rapid and reversible onset of action, and
be compatible with the drug formulation (Pfister et al., 1990,
Pharm. Tech. 14(9):132-140, incorporated herein by reference).
Penetration enhancers suitable for the purpose of the invention do
not adversely affect the host, the drug, or alter or adversely
affect the materials forming the transdermal delivery system. The
penetration enhances can be used alone or they can be admixed with
acceptable carriers and the like.
[0061] Useful penetration enhancers include but are not limited to
ethyl alcohol, isopropyl alcohol, or octolyphenylpolyethylene
glycol. More preferred penetration enhancers include oleic acid,
polyethylene glycol 400, propylene glycol, N-decylmethylsulfoxide,
fatty acid esters (e.g., isopropyl myristate, methyl laurate,
glycerol monooleate, and propylene glycol monooleate); N-methyl
pyrrolidone; monovalent, saturated and unsaturated aliphatic
cycloaliphatic and aromatic alcohols having 4 to 12 carbon atoms,
such as hexanol, cyclohexane and the like; aliphatic cycloaliphatic
and aromatic hydrocarbons having from 5 to 12 carbon atoms such as
hexane, cyclohexane, isopropylbenzene and the like; cycloaliphatic
and aromatic aldehydes and ketones having from 4 to 10 carbon atoms
such as cyclohexanone; acetamide; N,N-di(lower) alkyl acetamides
such as N,N-diethyl acetamide, N,N-dimethyl acetamide,
N-(2-hydroxyethyl) acetamide, and the like; and other transporting
agents such as aliphatic, cycloaliphatic and aromatic esters;
N,N-di(lower) alkyl sulfoxides; essential oils; halogenated or
nitrated aliphatic, cycloaliphatic and aromatic hydrocarbons;
salicylate; polyalkylene glycol silicates; surfactants; mixtures
thereof; and the like.
[0062] Alternatively, permeation of a therapeutic agent may be
enhanced by removing hair from the application site by, e.g.
clipping, shaving or use of a depilatory agent. Another permeation
enhancer is heat. It is thought that heat enhancement can be
induced by, among other things, using a radiating heat form, such
as an infrared lamp, onto the application site after application of
the transdermal patch.
[0063] Various methods may be used to place therapeutic agents or
drugs onto the patch. For example, the therapeutic agent may be
placed onto the patch by absorption, adsorption, chemical bond, and
covalent bond.
[0064] For drug-in-matrix type patches, the therapeutic agent is
dissolved or suspended in a polymer matrix film through which the
active agent diffuses to the skin as disclosed in U.S. Pat. Nos.
4,839,174, 4,908,213, and 4,943,435.
[0065] The therapeutic agents or drugs suitable for use in this
invention may be present in the reservoir, matrix, or microcapsules
as explained supra. A carrier may be used together with the
therapeutic agent when placed on the patch. The carrier material
will typically be one of two types. One type bioerodes rather
uniformly over time, so that the bioerosion of the carrier is also
the primary mechanism for releasing the drug from a patch. The
second type is a material which essentially remains intact during a
substantial portion of the release period of the drug. The
mechanism of release of the drug is by diffusion or other mechanism
which does not require the carrier to be concurrently bioeroded.
Many carrier materials may be suitable for various embodiments of
the system of the present invention. These carrier materials may be
natural products, such as keratin, triglycerides, fatty acids,
lipids, latexes, as well as derivatives, salts of cellulose
derivatives, alkaline or alkaline earth salts of cellulose acetate
phthalate, ammonium salts of hydroxypropyl methyl cellulose
phthalate, polysaccharide, synthetic polymers, such as,
polyglycolic acid and derivatives of polyethylene glycol,
polycaprolactone, polylactic acid, and copolymers thereof;
materials such as starch, fatty alcohols, alginate polymers,
albumin, calcium caseinate, calcium polypectate or gellan gum.
[0066] Adhesives for use with the drug-in-adhesive type patch are
well known in the art and selection is readily accomplished by an
ordinary practitioner. Three basic types commonly used are
polyisobutylenes, silicones, and acrylics. Adhesives useful in the
present invention can function under a wide range of conditions,
such as, high and low humidity, bathing, sweating etc. Preferably
the adhesive is a composition based on natural or synthetic rubber,
polyacrylate, polyvinylacetate, polybutylacrylate,
polymethylacrylate, polydimethylsiloxane, and hydrogels (e.g., high
molecular weight polyvinylpyrrolidone and oligomeric polyethylene
oxide). The most preferred is polyacrylate.
[0067] Therapeutic agents or drugs may also be glued onto the patch
by means of a number of known synthetic, naturally-occurring or
modified naturally-occurring substances which exhibit tackiness.
The adhesive should be compatible with the material forming the
carrier, as well as the drug. A variety of adhesives are suitable
for the present invention, both for adhering a patch on the skin or
mucosa, and for retaining therapeutic agent or drugs onto the
patch. One adhesive is a hydrogel composed of gelatin and
poly(L-glutamic acid) (PLGA). The hydrogel is formed by chemically
cross linking gelatin and poly(L-glutamic acid). Another adhesive
is fibrin glue. Suitable fibrin glue includes fibrinogen, thrombin,
calcium chloride and factor VIII. Another family of adhesives is
cyanoacrylates. Preferred cyanoacrylates include
butyl-2-cyanoacrylate (Histoacryl), ethyl-2-cyanoacrylate, and
octyl-2-cyanoacrylate. Gelatin-resorcinol
formaldehyde-glutaraldehyde is another suitable adhesive. Others
include carboxymethyl and hydroxypropyl methyl cellulose, and other
cellulose derivatives; tragacanth, caraya, locust bean and other
synthetic and natural gums such as algin, chitosan, starches,
pectin, and naturally-occurring resins. In addition, many polymers
having suitable adhesive properties can also be utilized, including
without limitation: polyurethanes having amino groups, di- and
tri-functional diols; polyvinyl acetates; polyamides; polyvinyl
alcohols; polyvinyl pyrrolidone, polyacrylic acid; polystyrene;
polylactides; polylactones; block co-polymers including polyesters,
polyamides, and polyurethanes; and combinations and mixtures
thereof.
[0068] In another embodiment, the therapeutic agent is applied onto
the patch as a coating or layer. More than one coating of different
therapeutic agents may be applied to the patch so that more than
one therapeutic agent and/or carrier may be incorporated onto the
patch. The placement of the different layers may be determined by
the diffusion or elution rates of the therapeutic agent involved as
well as the desired rate of delivering the therapeutic agent to the
body tissue.
[0069] Selection of the appropriate dosage for transdermal delivery
of therapeutic agent is an important consideration. The amount of
active agent to be incorporated onto the patch to obtain the
desired therapeutic effect will vary depending upon the desired
dosage, the permeability of the rate controlling materials of the
patch which are employed to the particular agent to be used, and
the length of time the patch is to remain on the skin or body
mucosa. Since this invention is designed to provide titratable
dosage of drug. The dosage provided by the transdermal delivery
system is proportional to the number of patch unit applied. The
lower limit for dosages is determined by the fact that sufficient
amounts of the drug must remain in each patch unit to maintain the
minimum possible dosage. The dosages and dosing frequency will be
determined by a trained medical professional. The concentration or
loading of the therapeutic agent onto the therapeutic patch may be
varied according to the therapeutic effects desired. Also, the
loading, in terms of the ratio of therapeutic agent to carrier in
the patch will depend upon the type of therapeutic agent and
carrier used and the rate at which the therapeutic agent on the
patch is released to the body tissue. Generally, the patch may
contain 0.1-90% by weight or preferably 10-45% by weight of the
therapeutic agent. Most preferably, 25-40% by weight of the
therapeutic agent should be incorporated in the patch.
[0070] Concentrations of the drugs in the transdermal delivery
system are virtually unlimited since delivery rate is controlled in
various types of patches by a release limiting layer and an
adhesive layer. However, the concentration must be at least great
enough so that the drug will leave the vehicle once the protective
cover layer is removed. One advantage of the present invention is
that should the amount of drug/unit area/unit time be insufficient
to render an appropriate dose of the drug, additional units of the
transdermal patch of the present invention may be employed.
However, it is more advantageous to utilize concentrations of drug
sufficiently high so that patch size is kept down. Most
advantageous are systems capable of delivering the drug in a
therapeutically useful degree in an area reasonably related to the
application site in view of medical, aesthetic, and patient
convenience considerations. These limitations are well known to
product designers in the art.
Method of Making the Transdermal Delivery System
[0071] The present invention also relates to methods of making the
transdermal delivery system. The method of the present invention
generally involves forming a backing layer with a top surface and a
bottom surface. The backing layer is divided into more than one
unit at one or more lines of separation. A drug layer is disposed
on the top surface of each unit of the backing layer, leaving a
border on all sides of each of the unit of the backing layer. An
adhesive means is used to attach the transdermal delivery system
onto the skin or mucosa of the patient.
[0072] In one embodiment, the method further comprises disposing an
adhesive layer on the drug layer and the border of the backing
layer. A cover layer is then disposed on top of the adhesive layer.
In one embodiment, the method of the present invention involves
forming a backing layer with a top surface and a bottom surface.
The backing layer is divided into more than one unit at one or more
lines of separation. A drug-in-matrix layer is then disposed on the
top surface of each unit of the backing layer, leaving a border on
all sides of the backing layer. An adhesive layer is then disposed
on the drug-in-matrix layer and the border of the backing layer.
Finally, a cover layer is disposed on top of the adhesive
layer.
[0073] The lines of separation formed distinct patch units on the
backing layer. They also define each unit of the transdermal
delivery system. The backing layer is made of materials as
described supra. The backing layer has one or more lines of
separation. A plurality of lines of separation are preferably
parallel and/or perpendicular to each other. The lines of
separation are also preferably spaced at regular intervals along
the length and/or width of the backing. Preferably, the lines of
separation are about 1 cm to 6 cm apart. The lines of separation
may be in various forms as long as they allow for relatively clean
separation of a desired number of units of the transdermal delivery
system by the user as directed by a physician. The lines of
separation may also be a weakness of the backing or a printed line
of division so that a patient may tear along or use scissors to cut
along the line. A preferred line of separation is a line of
perforations. The weakness of the backing may be a thinning of the
backing that is molded or formed in the backing. In some instances,
it may be desirable to combine a line of weakness with perforations
to ensure clean separation of the transdermal delivery system into
a desired number of units for optimal dosage application. Other
useful methods of constructing the lines of separation are
disclosed in U.S. Pat. No. 5,496,605. It is important that the
lines of separation allow easy division of the transdermal delivery
system into desired number of units per application. Although the
transdermal delivery system have been described as a transdermal
delivery system having one or more lines of separation, those
skilled in the art will understand that, alternatively, the present
invention can also be characterized as a plurality of units of
transdermal delivery patches connected to each other along the same
line or lines of separation. Regardless of the characterization,
the present invention provides a transdermal delivery system for
and method of delivering therapeutic agent or drug of varying
dosages using a single transdermal delivery system.
[0074] A drug-in-matrix layer is formed by dissolving or suspending
a therapeutic agent in a polymer matrix through which the active
agent diffuses to the skin. Methods of forming a drug-in-matrix
layer are disclosed in U.S. Pat. Nos. 4,839,174, 4,840,796,
4,908,213, and 4,943,435. When a drug-in-matrix layer is disposed
on the top surface of each unit of the backing layer, the
drug-in-matrix layer is not coextensive with the entire unit of the
backing layer. A border is left on all sides so that the backing
layer is not entirely covered by the drug-in-matrix layer. This is
to prevent the drug from seeping through the lines of separation.
Various methods may be used to place a drug on the transdermal
delivery system as discussed infra. An adhesive layer is then
disposed on the drug-in-matrix layer, the adhesive layer also
covers the border of the backing layer. The border is preferably
uniform in width and can range from about 0 (zero) cm to about 2.0
cm. A cover layer is disposed on the adhesive layer so that each
patch unit of the transdermal delivery system is protected
separately. A notch is formed on the cover layer so as to
facilitate separation of the cover layer from the adhesive layer
when the transdermal patch is ready for use.
[0075] The present invention further provides a method of making
the system of the present invention which involves forming a
plurality of reservoir compartments within an enclosure defined by
the raised wall directly on a backing layer. Each reservoir
compartment is surrounded by a border having a surface. The
plurality of the reservoirs are divided by one or more lines of
separation on the border. A drug layer is disposed onto each unit
of the reservoir compartment. An adhesive layer is then disposed on
top of the drug layer and on the surface of the border. A cover
layer is then disposed on the adhesive layer.
[0076] In this method of making a transdermal delivery system of
the present invention, a plurality of reservoir compartments are
formed on a backing layer. As mentioned earlier, each patch unit is
surrounded by a border. The sidewalls of the reservoir compartment
may be formed on the backing layer by raising the surrounding
border or making a depression within the border. The height of the
raised wall is determined by the quantity of therapeutic agent that
is to be deposited in the reservoir compartment. However, it should
be less than 5 mm so that it is comfortable for use by the patient.
Each reservoir compartment is surrounded by a border. A line of
separation is present on the border which allows the reservoir
compartments to be separated into units.
[0077] The present invention also provides a method of making the
system of the present invention which involves forming a backing
layer with a top surface and a bottom surface. The backing layer is
divided into more than one unit at one or more lines of separation.
A drug-in-adhesive layer is disposed on the top surface of each
unit of the backing layer, leaving a border on all sides of the
backing layer. Then, a cover layer is disposed on top of the
adhesive layer.
[0078] In this method of making a transdermal delivery system of
the invention, the drug-in-adhesive layer is formed by mixing one
or more drugs with an adhesive and dispose the composition on the
top surface of each unit on the backing layer. A cover layer is
disposed on the drug-in-adhesive layer so that each unit of the
transdermal delivery system is protected separately.
[0079] The present invention further provides a method of making
the system of the present invention which involves forming a
backing layer with a top surface and a bottom surface. The backing
layer is divided into more than one unit at one or more lines of
separation. A drug-in-adhesive layer is disposed on the top surface
of each unit of the backing layer, leaving a border on all sides of
the backing layer. A semi-permeable membrane is disposed on the
drug-in-adhesive layer. The semi-permeable membrane is secured to
the backing film so as to hold the drug-in-adhesive within the
border. A second drug-in-adhesive layer is then disposed on the
semi-permeable membrane. The border is then covered with an
adhesive. Finally, a cover layer is disposed on top of each unit
patch.
[0080] In this method of making a transdermal delivery system of
the invention, the composition that is used to make a
drug-in-adhesive layer is formed by mixing one or more drugs with
an adhesive and dispose the composition on the top surface of each
unit on the backing layer within the border.
Method of Use for the Invention
[0081] The method of the present invention can be used to deliver
therapeutic agents or drugs systemically through the skin or mucosa
of a patient.
[0082] The method comprises the steps of providing a transdermal
delivery system of the invention. The user then separates the
prescribed number of patch units from the transdermal delivery
system along at least one line of separation along the border. The
cover layer is then removed, exposing the adhesive layer and
applying the prescribed number of the transdermal delivery patch
units on the skin or mucosa. Alternatively, the user may remove the
cover layer for a prescribed number of patch units from the
transdermal delivery system and then separates the prescribed
number of patch units from the transdermal delivery system. Under
the direction of a physician, the user may increase or decrease the
number of patch units used per application. In a preferred
embodiment, the number of patch units used per application may be
one, two, three, four or five.
[0083] The rate of transdermal delivery from the therapeutic patch
is a function of skin permeability, and skin permeability has been
shown to vary between anatomical sites depending on the thickness
of the stratum corneum. For example, the permeability, in general,
increases in order from planter foot arch, lateral ankle, palm,
ventral forearm, dorsal forearm, back, chest, thigh, abdomen,
scalp, axilla, forehead, and scrotum (Wester, R. C. and Maibach, H.
I. (1989) Regional variation in Percutaneous Absorption: In
Percutaneous Absorption, Mechanism, Methodology, Drug Delivery,
2.sup.nd ed., Eds. R. L. Bronaugh and H. I. Maibach, Marcel Dekker,
Inc., New York, pp. 111-119).
[0084] The transdermal delivery system of the invention may be
applied directly to any area of the patient's skin, with the lower
back, chest, upper arm, and buttocks being the areas of choice. In
like manner, the patch can be applied to the mucosa of the mouth,
for example, by application to the palate or the buccal mucosa, to
obtain absorption of the drug by the oral mucosa. Similarly, where
desired and accessible, the patch can be applied to other mucosa
membranes.
[0085] In a preferred embodiment, the transdermal delivery system
comprising a plurality of therapeutic patch units is stored in a
resealable pouch. For each application, the transdermal delivery
system is removed from the pouch and a prescribed number of patch
units are removed from the pouch and applied on the skin or mucosa
of a patient. The remaining patch units are placed in the
resealable pouch.
[0086] In a preferred embodiment, the sustained delivery of the
therapeutic agent will be for an extended period, longer than about
three days and preferably, at least about one week. For treatment
of cancer or other chronic conditions, it is preferred that the
drug be delivered over a period up to about one month.
[0087] Whereas the invention has been shown and described in
connection with specific embodiments hereof, many modifications,
substitutions and additions may be made which are within the
intended broad scope of the appended claims. Thus, it should be
understood that the present invention encompasses the use of other
methods and titratable dosage transdermal delivery systems for
systemic delivery of adjustable dose of therapeutic agent to a
patient.
[0088] Various references are cited herein, the disclosure of which
are incorporated by reference in their entireties.
* * * * *