U.S. patent application number 15/832939 was filed with the patent office on 2018-04-05 for sodium channel blockers for skin disorders.
This patent application is currently assigned to PARION SCIENCES, INC.. The applicant listed for this patent is PARION SCIENCES, INC.. Invention is credited to Richard C. Boucher, Michael Ross Johnson, William Robert Thelin.
Application Number | 20180092915 15/832939 |
Document ID | / |
Family ID | 56692650 |
Filed Date | 2018-04-05 |
United States Patent
Application |
20180092915 |
Kind Code |
A1 |
Johnson; Michael Ross ; et
al. |
April 5, 2018 |
SODIUM CHANNEL BLOCKERS FOR SKIN DISORDERS
Abstract
Provided are methods of treating a variety of disorders of the
skin with inhibitors of the epithelial sodium channel (ENaC). The
inhibitors are represented by formula (I)-(IV): ##STR00001## where
R is defined herein.
Inventors: |
Johnson; Michael Ross;
(Chapel Hill, NC) ; Thelin; William Robert;
(Chapel Hill, NC) ; Boucher; Richard C.; (Chapel
Hill, NC) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
PARION SCIENCES, INC. |
Durham |
NC |
US |
|
|
Assignee: |
PARION SCIENCES, INC.
Durham
NC
|
Family ID: |
56692650 |
Appl. No.: |
15/832939 |
Filed: |
December 6, 2017 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
15047274 |
Feb 18, 2016 |
9849129 |
|
|
15832939 |
|
|
|
|
62117724 |
Feb 18, 2015 |
|
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
A61K 9/0014 20130101;
A61K 31/4965 20130101; A61K 31/497 20130101; A61P 17/00
20180101 |
International
Class: |
A61K 31/4965 20060101
A61K031/4965; A61K 31/497 20060101 A61K031/497; A61K 9/00 20060101
A61K009/00 |
Claims
1. A method of treating a disorder of the skin in a human in need
thereof comprising administering to the human an effective amount
of a compound represented by formula (I)-(IV): ##STR00025##
##STR00026## ##STR00027## ##STR00028## ##STR00029## ##STR00030##
##STR00031## ##STR00032## ##STR00033## ##STR00034## ##STR00035##
##STR00036## ##STR00037## ##STR00038## ##STR00039## or a
pharmaceutically acceptable salt thereof.
2. The method of claim 1, wherein the disorder of the skin is
psoriasis.
3. The method of claim 1, wherein the disorder of the skin is an
inflammatory disease of the skin.
4. The method of claim 1, wherein the disorder of the skin is a
wound.
5. The method of claim 1, wherein the disorder of the skin is a
lesion or ulcer of the skin.
6. The method of claim 1, wherein the disorder of the skin is
eczema.
7. The method of claim 1, wherein the disorder of the skin is
lupus.
8. The method of claim 1, wherein the disorder of the skin is
rosacea.
9. The method of claim 1, wherein the disorder of the skin is a
skin rash.
10. The method of claim 1, wherein the disorder of the skin is a
cold sore, shingles or acne.
11. The method of claim 1, wherein the compound represented by
formula (I)-(IV) is administered topically.
12. The method of claim 1, wherein the compound represented by
formula (I)-(IV) is a pharmaceutically acceptable salt.
13. A method of minimizing scarring in a human in need thereof
comprising administering to the human an effective amount of a
compound represented by formula (I)-(IV): ##STR00040## ##STR00041##
##STR00042## ##STR00043## ##STR00044## ##STR00045## ##STR00046##
##STR00047## ##STR00048## ##STR00049## ##STR00050## ##STR00051##
##STR00052## ##STR00053## ##STR00054## or a pharmaceutically
acceptable salt thereof.
14. The method of claim 13, wherein the compound represented by
formula (I)-(IV) is administered topically.
15. The method of claim 13, wherein the compound represented by
formula (I)-(IV) is a pharmaceutically acceptable salt.
Description
CONTINUING APPLICATION INFORMATION
[0001] This application is a continuation application of U.S.
application Ser. No. 15/047,274 filed Feb. 18, 2016, allowed, and
claims benefit to U.S. Provisional Application Ser. No. 62/117,724,
filed on Feb. 18, 2015, and incorporated herein by reference.
BACKGROUND OF THE INVENTION
Field of the Invention
[0002] The present invention is directed to the use of inhibitors
of the epithelial sodium channel (ENaC) for treating a variety of
conditions affecting the skin.
Description of the Background
[0003] Skin is the physical barrier separating an organism and its
environment, which prevents water loss and protects from chemical,
mechanical, and microbial attacks. To perform these functions, the
epidermis, as the outer layer of the skin, undergoes
keratinization, a process in which epidermal cells mature from
proliferative basal cells to the terminally differentiated cells of
the stratum corneum. The differentiation of epidermal basal cells
is caused by changes in protein and enzymes which regulate
metabolic changes and alterations in lipid synthesis and
composition.
[0004] Hydration is important to the process of epithelial wound
healing, as healing that occurs in a wet environment, is faster and
results in less scarring. Essential to the healing process are the
ability of the epithelium to: (1) re-stablish the water barrier and
(2) reduce inflammatory cytokine expression. Recent studies suggest
that reduced hydration upon disruption of stratum corneum can cause
an ion flux of epithelial cells and that the reduction of hydration
caused by skin barrier disruption leads to greater changes in local
ion concentrations. As sodium is the most abundant cation in skin
extracellular matrix, it is believed to be involved in keratinocyte
differentiation and normal epidermal growth. The epithelial sodium
channel (ENaC) has been described as an important regulator of
epidermal homeostasis and wound healing, both involved in epidermal
"sensing" of the water barrier function and inflammatory pathways
associated with scarring.
[0005] ENaC is a member of the ENaC/degenerin family of ion
channels. They are highly Na.sup.+ selective channels that are
comprised of three structurally related subunits (.alpha., .beta.
and .gamma.) that share a similar secondary structure consisting of
an extracellular region linked to two transmembrane domains. In
some tissues, a fourth .delta.-ENaC subunit may be expressed,
resulting in the formation of channels with distinct biophysical
characteristics. The resolved structure of a related channel, the
acid sensing ion channel (ASIC1), has provided insights into the
structural organization of the ENaCs, suggesting that functional
channels are heterotrimeric subunits.
[0006] ENaCs mediate Na.sup.+ transport across apical or luminal
membranes, providing the rate-limiting step of transepithelial
Na.sup.+ uptake. ENaCs are expressed in many salt-reabsorbing
epithelia, including the renal distal nephron, airway, and colon.
ENaC-mediated Na.sup.+ absorption in the distal nephron has an
essential role in extracellular volume homeostasis and blood
pressure regulation, while Na.sup.+ absorption in the airway has a
key role in regulating airway surface liquid volume and the rate of
mucus transport.
[0007] In the epidermis, keratinocytes express amiloride-sensitive
ENaCs which has been demonstrated to be required for normal barrier
function. Systemic genetic depletion of .alpha.-ENaC in mice has
been shown to disrupt the formation of then normal skin barrier,
highlighting the importance of ENaC in the epidermis. Furthermore,
ENaC-mediated sodium flux in keratinocytes increases the secretion
of inflammatory cytokines via the COX-2/prostaglandin E.sub.2
(PGE.sub.2) pathway (Charles, R.-P., Guitard, M., Leyvraz, C.,
Breiden, B., Haftek, M., Haftek-Terreau, Z., Hummler, E. (2008).
Postnatal requirement of the epithelial sodium channel for
maintenance of epidermal barrier function. The Journal of
Biological Chemistry, 283(5), 2622-30). The role of ENaC as an
upstream mediator of prostaglandin E.sub.2 release has been further
confirmed in the uterine endometrium, where ENaC is required for
embryo implantation. (Ruan, Y. C., Guo, J. H., Liu, X., Zhang, R.,
Tsang, L. L., Dong, J. Da, Chan, H. C. (2012). Activation of the
epithelial Na+ channel triggers prostaglandin E.sub.2 release and
production required for embryo implantation. Nature Medicine,
18(7), 1112-7). As such, the inhibition of ENaC in keratinocytes
has been proposed to promote healing of the skin via multiple
processes that may include changes in keratinocyte differentiation,
proliferation, and inflammatory signaling. (Xu, W., Hong, S. J.,
Zeitchek, M., Cooper, G., Jia, S., Xie, P., Mustoe, T. (2014).
Hydration Status Regulates Sodium Flux and Inflammatory Pathways
through Epithelial Sodium Channel (ENaC) in Skin. The Journal of
Investigative Dermatology, (August), 1-26; Maubec, E., Laouenan,
C., Deschamps, L., Nguyen, V. T., Scheer-Senyarich, I.,
Wackenheim-Jacobs, A.-C., Farman, N. (2015). Topical
Mineralocorticoid Receptor Blockade Limits Glucocorticoid-Induced
Epidermal Atrophy in human Skin. The Journal of Investigative
Dermatology, (February). Doi:10.1038; Sharma, R. K., Gupta, B.,
& Sharma, B. (2014). Original Article Topical amiloride delays
healing of deep thermal wounds in albino rabbits, 58(3), 251-261;
Sharma, R. K., Gupta, B., & Sharma, B. (2014). Original Article
Topical amiloride delays healing of deep thermal wounds in albino
rabbits, 58(3), 251-261.).
[0008] The inhibition of ENaC mediated Na.sup.+ transport and
downstream signaling pathways can be accomplished with an ENaC
blocker of the amiloride class (which blocks from the extracellular
domain of ENaC). In dermal wound healing studies in animals and
man, topical application of amiloride has been shown to accelerate
the rate of wound healing. These findings are consistent with the
role of ENaC in epidermal hydration and local inflammatory
processes. Importantly, ENaC inhibitors must be maintained on the
extracellular surface of the target tissue, at the site of the
channel, to achieve and maintain the therapeutic utility.
[0009] The present invention describes conditions in which the
inhibition of ENaC promotes hydration of the skin and/or prevents
inflammatory signaling cascades in the skin in order to facilitate
healing. Furthermore, the present invention describes ENaC
inhibitors with increased potency, reduced cellular absorption, and
slow dissociation ("unbinding" or detachment) from ENaC that are
required for the therapy of skin conditions
SUMMARY OF THE INVENTION
[0010] It is an object of the present invention to provide
compounds to treat a variety of disorders of the skin.
[0011] It is another object of the present invention to provide
treatments for inflammatory diseases affecting the skin.
[0012] It is another object of the present invention to provide
treatments for wound healing.
[0013] It is another object of the present invention to provide
treatments for psoriasis.
[0014] It is an object of the present invention to provide
treatments that are administered topically.
[0015] It is another object of the present invention to provide
treatments that are administered orally.
[0016] It is another object of the present invention to provide
compounds that inhibit ENaCs with enhanced potency and specificity
compared to amiloride, benzamil, and phenamil.
[0017] In one embodiment of the present invention, ENaC blockers
capable of inhibiting ENaC with a long duration of action are
provided.
[0018] It is another object of the present invention to provide
methods of treatment which take advantage of the properties
described above.
[0019] It is another aspect of the present invention to provide
compounds that are more potent and/or absorbed less rapidly and/or
exhibit less reversibility, as compared to compounds such as
amilorde, benzamil, and phenamil. Therefore, the compounds will
give a prolonged pharmacodynamic half-life on skin surfaces as
compared to those known compounds.
[0020] It is another object of the present invention to provide
compounds which are (1) absorbed less rapidly from skin surfaces,
as compared to known compounds and (2) when absorbed from skin
surfaces after administration to the skin surfaces, are converted
in vivo into metabolic derivatives thereof which have reduced
efficacy in blocking sodium channels as compared to the
administered parent compound.
[0021] It is another object of the present invention to provide
compounds that are more potent and/or absorbed less rapidly and/or
exhibit less reversibility, as compared to compounds such as
amiloride, benzamil, and phenamil. Therefore, such compounds will
give a prolonged pharmacodynamic half-life on skin surfaces as
compared to previous compounds.
[0022] It is another object of the present invention to provide
methods of treatment that take advantage of the pharmacological
properties of the compounds described above.
[0023] In particular, it is an object of the present invention to
provide methods of treatment which rely on rehydration of dermal
mucosal surfaces.
[0024] The objects of the present invention may be accomplished
with a class of pyrazinoylguanidine compounds represented by
formulas (I), (II), (III), and (IV):
##STR00002## ##STR00003## ##STR00004## ##STR00005## ##STR00006##
##STR00007## ##STR00008## ##STR00009## ##STR00010## ##STR00011##
##STR00012## ##STR00013## ##STR00014## ##STR00015##
##STR00016##
[0025] The present invention also provides solvates and hydrates,
individual stereoisomers, including optical isomers (enantiomers
and diastereomers) and geometric isomers (cis-/trans-isomerism),
mixtures of stereoisomers, and tautomers of compounds of the
formulas (I)-(IV), or a pharmaceutically acceptable salt thereof,
as well as pharmaceutical compositions comprising the compounds, or
a pharmaceutically acceptable salts thereof, their use in methods
of treatment, and methods for their preparation.
[0026] Thus, the present invention relates to a method of treating
a disorder of the skin in a human in need thereof comprising
administering to the human an effective amount of a compound
represented by formula (I)-(IV) or a pharmaceutically acceptable
salt thereof.
[0027] In one embodiment of the invention, the disorder of the skin
is psoriasis.
[0028] In another embodiment of the present invention, the disorder
of the skin is an inflammatory disease of the skin.
[0029] In one embodiment, the disorder of the skin is a wound.
[0030] In another embodiment of the present invention, the disorder
of the skin is a lesion or ulcer of the skin.
[0031] In yet another embodiment, the disorder of the skin is
eczema.
[0032] In one embodiment, the disorder of the skin is lupus.
[0033] In another embodiment, the disorder of the skin is
rosacea.
[0034] In another embodiment of the present invention, the disorder
of the skin is a skin rash.
[0035] In another embodiment of the invention, the disorder of the
skin is a cold sore, shingles or acne.
[0036] In a preferred embodiment of the reference, the compound
represented by formula (I)-(IV) is administered topically to treat
the disorder of the skin.
[0037] The present invention also relates to a method of minimizing
scarring in a human in need thereof comprising administering to the
human an effective amount of a compound represented by formula by
formula (I)-(IV) as described above or a pharmaceutically
acceptable salt thereof.
BRIEF DESCRIPTION OF THE DRAWINGS
[0038] FIG. 1. Amiloride and its analogues, but not Compound 2
penetrate cells. Benzamil or Compound 2 (10 uM each) were added to
the apical compartment of primary human airway epithelial cells.
After a 60 minute incubation, the compounds were visualized by
confocal microscopy. Note, although the compounds were added in a
large volume which can be seen as the red "haze" in the upper
(apical) compartment, Compound 2 has concentrated on the exterior
cell surface. Benzamil, however, has largely concentrated inside
cells.
[0039] FIG. 2. Confocal images showing the x-z reconstruction of
mouse corneas imaged as either the corneal cells (Calcein labeled)
or the treatment drug (amiloride or Compound 3) taken one hour
after application to the corneal epithelium.
DETAILED DESCRIPTION OF THE INVENTION
[0040] As used herein, the following terms are defined as
indicated:
[0041] "A compound of the invention" means a compound of Formula
(I)-(IV) or a salt, particularly a pharmaceutically acceptable salt
thereof.
[0042] "A compound of Formula (I)-(IV)" means a compound having the
structural formula designated herein as Formula (I)-(IV). Compounds
of Formula (I)-(IV) include solvates and hydrates (i.e., adducts of
a compound of Formula (I)-(IV) with a solvent). In those
embodiments where a compound of Formula (I)-(IV) includes one or
more chiral centers, the phrase is intended to encompass each
individual stereoisomer including optical isomers (enantiomers and
diastereomers) and geometric isomers (cis-/trans-isomerism) and
mixtures of stereoisomers. In addition, compounds of Formula
(I)-(IV) also include tautomers of the depicted formula(s).
[0043] Throughout the description and examples, compounds are named
using standard IUPAC naming principles, where possible, including
the use of the ChemDraw Ultra 11.0 software program for naming
compounds, sold by CambridgeSoft Corp./PerkinElmer.
[0044] In some chemical structure representations where carbon
atoms do not have a sufficient number of attached variables
depicted to produce a valence of four, the remaining carbon
substituents needed to provide a valence of four should be assumed
to be hydrogen. Similarly, in some chemical structures where a bond
is drawn without specifying the terminal group, such bond is
indicative of a methyl (Me, --CH.sub.3) group, as is conventional
in the art.
[0045] The compounds herein, including those of Formulas (I), (II),
(III), and (IV) may be in the form of a free base or a salt,
particularly a pharmaceutically acceptable salt. For a review of
pharmaceutically acceptable salts see Berge et al., J. Pharma Sci.
(1977) 66:1-19.
[0046] Pharmaceutically acceptable salts formed from inorganic or
organic acids include for example, hydrochloride, hydrobromide,
hydroiodide, sulfate, bisulfate, nitrate, sulfamate, phosphate,
hydrogen phosphate, acetate, trifluoroacetate, maleate, malate,
fumarate, lactate, tartrate, citrate, formate, gluconate,
succinate, pyruvate, tannate, ascorbate, palmitate, salicylate,
stearate, phthalate, alginate, polyglutamate, oxalate,
oxaloacetate, saccharate, benzoate, alkyl or aryl sulfonates (e.g.,
methanesulfonate, ethanesulfonate, benzenesulfonate,
p-toluenesulfonate or naphthalenesulfonate) and isothionate;
complexes formed with amino acids such as lysine, arginine,
glutamic acid, glycine, serine, threonine, alanine, isoleucine,
leucine and the like. The compounds of the invention may also be in
the form of salts formed from elemental anions such as chlorine,
bromine or iodine.
[0047] For therapeutic use, salts of active ingredients of the
compounds of Formula (I)-(IV) will be pharmaceutically acceptable,
i.e., they will be salts derived from a pharmaceutically acceptable
acid. However, salts of acids which are not pharmaceutically
acceptable may also find use, for example, in the preparation or
purification of a pharmaceutically acceptable compound.
Trifluoroacetate salts, for example, may find such use. All salts,
whether or not derived from a pharmaceutically acceptable acid, are
within the scope of the present invention.
[0048] The term "chiral" refers to molecules which have the
property of non-superimposability of the mirror image partner,
while the term "achiral" refers to molecules which are
superimposable on their mirror image partner.
[0049] The term "stereoisomers" refers to compounds which have
identical chemical constitution, but differ with regard to the
arrangement of the atoms or groups in space. "Diastereomer" refers
to a stereoisomer with two or more centers of chirality and whose
molecules are not mirror images of one another. Diastereomers have
different physical properties, e.g., melting points, boiling
points, spectral properties, and reactivities. Mixtures of
diastereomers may separate under high resolution analytical
procedures such as electrophoresis and chromatography.
"Enantiomers" refer to two stereoisomers of a compound which are
non-superimposable mirror images of one another.
[0050] Stereochemical definitions and conventions used herein
generally follow S. P. Parker, Ed., MCGRAW-HILL DICTIONARY OF
CHEMICAL TERMS (1984) McGraw-Hill Book Company, New York; and
Eliel, E. and Wilen, S., STEREOCHEMISTRY OF ORGANIC COMPOUNDS
(1994) John Wiley & Sons, Inc., New York.
[0051] Many organic compounds exist in optically active forms,
i.e., they have the ability to rotate the plane of plane-polarized
light. In describing an optically active compound, the prefixes D
and L or R and S are used to denote the absolute configuration of
the molecule about its chiral center(s). A specific stereoisomer
may also be referred to as an enantiomer, and a mixture of such
isomers is often called an enantiomeric mixture. A 50:50 mixture of
enantiomers is referred to as a racemic mixture or a racemate,
which may occur where there has been no stereoselection or
stereospecificity in a chemical reaction or process. The terms
"racemic mixture" and "racemate" refer to an equimolar mixture of
two enantiomeric species.
[0052] The term "tautomers" refers to a type of stereoisomer in
which migration of a hydrogen atom results in two or more
structures. The compounds of Formula (I)-(IV) may exist in
different tautomeric forms. One skilled in the art will recognize
that amidines, amides, guanidines, ureas, thioureas, heterocycles
and the like can exist in tautomeric forms. By way of example and
not by way of limitation, compounds of Formula (I)-(IV) can exist
in various tautomeric forms as shown below:
##STR00017##
[0053] All possible tautomeric forms of the amidines, amides,
guanidines, ureas, thioureas, heterocycles and the like of all of
the embodiments of Formula (I)-(IV) are within the scope of the
present invention. Tautomers exist in equilibrium and thus the
depiction of a single tautomer in the formulas provided will be
understood by those skilled in the art to refer equally to all
possible tautomers.
[0054] It is to be noted that all enantiomers, diastereomers, and
racemic mixtures, tautomers, polymorphs, pseudopolymorphs of
compounds within the scope of Formula (I)-(IV) and pharmaceutically
acceptable salts thereof are embraced by the present invention. All
mixtures of such enantiomers and diastereomers, including
enantiomerically enriched mixtures and diastereomerically enriched
mixtures are within the scope of the present invention.
[0055] Enantiomerically enriched mixtures are mixtures of
enantiomers wherein the ratio of the specified enantiomer to the
alternative enantiomer is greater than 50:50. More particularly, an
enantiomerically enriched mixture comprises at least about 75% of
the specified enantiomer, and preferably at least about 85% of the
specified enantiomer. In one embodiment, the enantiomerically
enriched mixture is substantially free of the other enantiomer.
[0056] Similarly, diastereomerically enriched mixtures are mixtures
of diastereomers wherein amount of the specified diastereomer is
greater than the amount of each alternative diastereomer. More
particularly, a diastereomerically enriched mixture comprises at
least about 75% of the specified diastereomer, and preferably at
least about 85% of the specified diastereomer. In one embodiment,
the diastereomerically enriched mixture is substantially free of
all other diastereomers.
[0057] The term "substantially free of" will be understood by those
skilled in the art to indicate less than a 5% presence of other
diastereomers, preferably less than 1%, more preferably less than
0.1%. In other embodiments no other diastereomers will be present
or the amount of any other diastereomers present will be below the
level of detection.
[0058] Stereoisomers may be separated by techniques known in the
art, including high performance liquid chromatography (HPLC) and
crystallization of chiral salts. A single stereoisomer, e.g., an
enantiomer, substantially free of its stereoisomer may be obtained
by resolution of the racemic mixture using a method such as
formation of diastereomers using optically active resolving agents
("Stereochemistry of Carbon Compounds," (1962) by E. L. Eliel,
McGraw Hill; Lochmuller, C. H., (1975) J. Chromatogr., 113:(3)
283-302). Racemic mixtures of chiral compounds of the invention can
be separated and isolated by any suitable method, including: (1)
formation of ionic, diastereomeric salts with chiral compounds and
separation by fractional crystallization or other methods, (2)
formation of diastereomeric compounds with chiral derivatizing
reagents, separation of the diastereomers, and conversion to the
pure stereoisomers, and (3) separation of the substantially pure or
enriched stereoisomers directly under chiral conditions
[0059] A compound of Formula (I)-(IV) and pharmaceutically
acceptable salts thereof may exist as different polymorphs or
pseudopolymorphs. As used herein, crystalline polymorphism means
the ability of a crystalline compound to exist in different crystal
structures. The crystalline polymorphism may result from
differences in crystal packing (packing polymorphism) or
differences in packing between different conformers of the same
molecule (conformational polymorphism). As used herein, crystalline
pseudopolymorphism also includes the ability of a hydrate or
solvate of a compound to exist in different crystal structures. The
pseudopolymorphs of the present invention may exist due to
differences in crystal packing (packing pseudopolymorphism) or due
to differences in packing between different conformers of the same
molecule (conformational pseudopolymorphism). The present invention
comprises all polymorphs and pseudopolymorphs of the compounds of
Formula (I)-(IV) and pharmaceutically acceptable salts thereof.
[0060] A compound of Formula (I)-(IV) and pharmaceutically
acceptable salts thereof may also exist as an amorphous solid. As
used herein, an amorphous solid is a solid in which there is no
long-range order of the positions of the atoms in the solid. This
definition applies, as well, when the crystal size is two
nanometers or less. Additives, including solvents, may be used to
create the amorphous forms of the present invention. The present
invention, including all pharmaceutical compositions, methods of
treatment, combination products, and uses thereof described herein,
comprises all amorphous forms of the compounds of Formula (I)-(IV)
and pharmaceutically acceptable salts thereof.
Uses
[0061] The compounds of the invention exhibit activity as sodium
channel blockers. Without being bound by any particular theory, it
is believed that the compounds of the invention may function in
vivo by blocking epithelial sodium channels present in mucosal
surfaces and thereby reduce the absorption of water by the mucosal
surfaces. This effect increases the volume of protective liquids on
mucosal surfaces and rebalances the system.
[0062] As a consequence, the compounds of the invention are useful
as medicaments, particularly for the treatment of clinical
conditions of the skin for which a sodium channel blocker may be
indicated. Such conditions include: [0063] Skin wound healing due
to mechanical damage, chemical, or burns [0064] Lesions or ulcers
of the skin including cold sores, shingles, acne [0065]
Inflammatory diseases of the skin: lupus, psoriasis, eczema,
rosacea [0066] Rashes of the skin: contact dermatitis and diaper
rash [0067] Scarring: ENaC blockers minimize the amount of scarring
after an injury.
[0068] The terms "treat", "treating" and "treatment", as used
herein refers to reversing, alleviating, inhibiting the progress
of, or preventing the disorder or condition or one or more symptoms
of such disorder or condition.
[0069] All therapeutic methods described herein are carried out by
administering an effective amount of a compound of the invention, a
compound of Formula (I)-(IV) or a pharmaceutically acceptable salt
thereof, to a subject (typically mammal and preferably human) in
need of treatment.
[0070] It is an object of the present invention to provide
compounds used to treat skin diseases and wounds that will achieve
an effective dose at the site of action (epidermis) without
producing undesirable systemic side effects. Thus, the present
invention is based on the discovery that the compounds of formula
(I)-(IV) are more potent and/or absorbed less rapidly from mucosal
surfaces, and/or are less reversible as compared to known compounds
such as amilorde, benzamil, and phenamil.
[0071] The present invention is also based on the discovery that
the compounds of formula (I)-(IV) are more potent and/or absorbed
less rapidly and/or exhibit less reversibility, as compared to
compounds such as amilorde, benzamil, and phenamil. Therefore, the
compounds will give a prolonged pharmacodynamic half-life on
mucosal surfaces as compared to known compounds. Table 1 provides
examples of compounds of formula (I)-(IV) that are more potent than
amiloride. Table 2 and FIGS. 1 and 2 provide examples of compounds
of formula (I)-(IV) that are less rapidly absorbed compared to
amiloride and benzamil.
[0072] The present invention is also based on the discovery that
certain compounds embraced by formula (I)-(IV) are absorbed less
rapidly from epithelial surfaces, including keratinized epithelium,
as compared to known compounds and (2) when absorbed from mucosal
surfaces after administration to the mucosal surfaces, are excreted
mainly non-renally in order to minimize the chances of
hyperkalemia.
[0073] The present invention is also based on the discovery that
certain compounds embraced by formula (I)-(IV) (1) are absorbed
less rapidly from mucosal surfaces, especially ocular surfaces, as
compared to known compounds and (2) are converted in vivo into
metabolic derivatives thereof which have reduced efficacy in
blocking sodium channels as compared to the administered parent
compound in order to minimize the chances of hyperkalemia.
[0074] The present invention is also based on the discovery that
certain compounds embraced by formula (I)-(IV) (1) are absorbed
less rapidly from mucosal surfaces, especially ocular surfaces, as
compared to known compounds and (2) are not converted in vivo into
metabolic derivatives thereof which have enhanced or similar
efficacy in blocking sodium channels as compared to the
administered parent compound in order to minimize the chances of
hyperkalemia.
[0075] The present invention is also based on the discovery that
certain compounds embraced by formula (I)-(IV) provide methods of
treatment that take advantage of the pharmacological properties of
the compounds described above.
[0076] In particular, the present invention is also based on the
discovery that certain compounds embraced by formula (I)-(IV)
promote healing of epithelial surfaces, including skin.
[0077] In particular, the present invention is also based on the
discovery that certain compounds embraced by formula (I)-(IV) are
useful in treating psoriasis and other dermatological diseases.
[0078] In particular, the present invention is also based on the
discovery that certain compounds embraced by formula (I)-(IV) are
useful in treating dermal wounds caused by trauma, burns, chemicals
injury, or resulting from inflammatory diseases.
[0079] In other embodiments, the present invention provides each of
the methods described herein with the additional benefit of
minimizing or eliminating hyperkalemia in the recipient of the
method. Also provided are embodiments comprising each of the
methods described herein wherein an improved therapeutic index is
achieved. In one embodiment, the invention provides a method for
the treatment of a condition which is ameliorated by increased
mucosal hydration in a mammal, particularly a human in need
thereof. There is also provided a compound of the invention for use
in medical therapy, particularly for use in the treatment of
condition in a mammal, such as a human, for which a sodium channel
blocker is indicated.
[0080] All therapeutic uses described herein are carried out by
administering an effective amount of a compound of the invention to
the subject in need of treatment. In one embodiment, there is
provided a compound of the invention for use in the treatment of
diseases associated with disorders of the skin in a mammal,
particularly a human, in need thereof.
[0081] The present invention also provides the use of a compound of
the invention in the manufacture of a medicament for the treatment
of a condition in a mammal, such as a human, for which a sodium
channel blocker is indicated. In one embodiment, the compounds of
the invention may be used in the manufacture of a medicament for
the treatment of diseases associated with disorders of the
skin.
[0082] The precise effective amount of the compounds of the
invention will depend on a number of factors including but not
limited to the species, age and weight of the subject being
treated, the precise condition requiring treatment and its
severity, the bioavailability, potency, and other properties of the
specific compound being administered, the nature of the
formulation, the route of administration, and the delivery device,
and will ultimately be at the discretion of the attendant physician
or veterinarian. Further guidance with respect to appropriate dose
may be found in considering conventional dosing of other sodium
channel blockers, such as amiloride, with due consideration also
being given to any differences in potency between amiloride and the
compounds of the present invention.
[0083] A pharmaceutically effective dose administered topically to
the dermal or airway surfaces of a subject (e.g., by inhalation) of
a compound of the invention for treatment of a 70 kg human may be
in the range of from about 10 ng to about 10 mg. In another
embodiment, the pharmaceutically effective dose may be from about
0.1 to about 1,000 .mu.g. Typically, the daily dose administered
topically to the dermal or airway surfaces will be an amount
sufficient to achieve dissolved concentration of active agent on
the airway surfaces of from about 10.sup.-9, 10.sup.-8, or
10.sup.-7 to about 10.sup.4, 10.sup.-3, 10.sup.-2, or 10.sup.-1
Moles/liter, more preferably from about 10.sup.-9 to about
10.sup.-4 Moles/liter.
[0084] The selection of the specific dose for a patient will be
determined by the attendant physician, clinician or veterinarian of
ordinary skill in the art based upon a number of factors including
those noted above. In one particular embodiment the dose of a
compound of the invention for the treatment of a 70 kg human will
be in the range of from about 10 nanograms (ng) to about 10 mg. In
another embodiment, the effective dose would be from about 0.1
.mu.g to about 1,000 .mu.g. In one embodiment, the dose of a
compound of the invention for the treatment of a 70 kg human will
be in the range of from about 0.5 .mu.g to about 0.5 mg. In a
further embodiment the dose will be from about 0.5 .mu.g to about
60 .mu.g. In another embodiment, the pharmaceutically effective
dose will be from about 1 to about 10 .mu.g. In another embodiment,
the pharmaceutically effective dose will be from about 5 .mu.g to
about 50 .mu.g. Another embodiment will have an effective dose of
from about 10 .mu.g to about 40 .mu.g. In two further embodiments,
the pharmaceutically effective dose will be from about 15 .mu.g to
about 50 .mu.g from about 15 .mu.g to about 30 .mu.g, respectively.
All specific values and subranges therebetween are included in the
present invention.
[0085] Thus, it will be understood that in each of these dose
ranges, all incremental doses in the range are included. For
instance, the 0.5-50 .mu.g range includes individual doses of: 0.5
.mu.g, 0.6 .mu.g, 0.7 .mu.g, 0.8 .mu.g, 0.9 .mu.g, 1.0 .mu.g, 1.1
.mu.g, 1.2 .mu.g, 1.3 .mu.g, 1.4 .mu.g, 1.5 .mu.g, 1.6 .mu.g, 1.7
.mu.g, 1.8 .mu.g, 1.9 .mu.g, 2.0 .mu.g, 2.1 .mu.g, 2.2 .mu.g, 2.3
.mu.g, 2.4 .mu.g, 2.5 .mu.g, 2.6 .mu.g, 2.7 .mu.g, 2.8 .mu.g, 2.9
.mu.g, 3.0 .mu.g, 3.1 .mu.g, 3.2 .mu.g, 3.3 .mu.g, 3.4 .mu.g, 3.5
.mu.g, 3.6 .mu.g, 3.7 .mu.g, 3.8 .mu.g, 3.9 .mu.g, 4.0 .mu.g, 4.1
.mu.g, 4.2 .mu.g, 4.3 .mu.g, 4.4 .mu.g, 4.5 .mu.g, 4.6 .mu.g, 4.7
.mu.g, 4.8 .mu.g, 4.9 .mu.g, 5.0 .mu.g, 5.1 .mu.g, 5.2 .mu.g, 5.3
.mu.g, 5.4 .mu.g, 5.5 .mu.g, 5.6 .mu.g, 5.7 .mu.g, 5.8 .mu.g, 5.9
.mu.g, 6.0 .mu.g, 6.1 .mu.g, 6.2 .mu.g, 6.3 .mu.g, 6.4 .mu.g, 6.5
.mu.g, 6.6 .mu.g, 6.7 .mu.g, 6.8 .mu.g, 6.9 .mu.g, 7.0 .mu.g, 7.1
.mu.g, 7.2 .mu.g, 7.3 .mu.g, 7.4 .mu.g, 7.5 .mu.g, 7.6 .mu.g, 7.7
.mu.g, 7.8 .mu.g, 7.9 .mu.g, 8.0 .mu.g, 8.1 .mu.g, 8.2 .mu.g, 8.3
.mu.g, 8.4 .mu.g, 8.5 .mu.g, 8.6 .mu.g, 8.7 .mu.g, 8.8 .mu.g, 8.9
.mu.g, 9.0 .mu.g, 9.1 .mu.g, 9.2 .mu.g, 9.3 .mu.g, 9.4 .mu.g, 9.5
.mu.g, 9.6 .mu.g, 9.7 .mu.g, 9.8 .mu.g, 9.9 .mu.g, 10.0 .mu.g, 10.1
.mu.g, 10.2 .mu.g, 10.3 .mu.g, 10.4 .mu.g, 10.5 .mu.g, 10.6 .mu.g,
10.7 .mu.g, 10.8 .mu.g, 10.9 .mu.g, 11.0 .mu.g, 11.1 .mu.g, 11.2
.mu.g, 11.3 .mu.g, 11.4 .mu.g, 11.5 .mu.g, 11.6 .mu.g, 11.7 .mu.g,
11.8 .mu.g, 11.9 .mu.g, 12.0 .mu.g, 12.1 .mu.g, 12.2 .mu.g, 12.3
.mu.g, 12.4 .mu.g, 12.5 .mu.g, 12.6 .mu.g, 12.7 .mu.g, 12.8 .mu.g,
12.9 .mu.g, 13.0 .mu.g, 13.1 .mu.g, 13.2 .mu.g, 13.3 .mu.g, 13.4
.mu.g, 13.5 .mu.g, 13.6 .mu.g, 13.7 .mu.g, 13.8 .mu.g, 13.9 .mu.g,
14.0 .mu.g, 14.1 .mu.g, 14.2 .mu.g, 14.3 .mu.g, 14.4 .mu.g, 14.5
.mu.g, 14.6 .mu.g, 14.7 .mu.g, 14.8 .mu.g, 14.9 .mu.g, 15.0 .mu.g,
15.1 .mu.g, 15.2 .mu.g, 15.3 .mu.g, 15.4 .mu.g, 15.5 .mu.g, 15.6
.mu.g, 15.7 .mu.g, 15.8 .mu.g, 15.9 .mu.g, 16.0 .mu.g, 16.1 .mu.g,
16.2 .mu.g, 16.3 .mu.g, 16.4 .mu.g, 16.5 .mu.g, 16.6 .mu.g, 16.7
.mu.g, 16.8 .mu.g, 16.9 .mu.g, 17.0 .mu.g, 17.1 .mu.g, 17.2 .mu.g,
17.3 .mu.g, 17.4 .mu.g, 17.5 .mu.g, 17.6 .mu.g, 17.7 .mu.g, 17.8
.mu.g, 17.9 .mu.g, 18.0 .mu.g, 18.1 .mu.g, 18.2 .mu.g, 18.3 .mu.g,
18.4 .mu.g, 18.5 .mu.g, 18.6 .mu.g, 18.7 .mu.g, 18.8 .mu.g, 18.9
.mu.g, 19.0 .mu.g, 19.1 .mu.g, 19.2 .mu.g, 19.3 .mu.g, 19.4 .mu.g,
19.5 .mu.g, 19.6 .mu.g, 19.7 .mu.g, 19.8 .mu.g, 19.9 .mu.g, 20.0
.mu.g, 20.1 .mu.g, 20.2 .mu.g, 20.3 .mu.g, 20.4 .mu.g, 20.5 .mu.g,
20.6 .mu.g, 20.7 .mu.g, 20.8 .mu.g, 20.9 .mu.g, 21.0 .mu.g, 21.1
.mu.g, 21.2 .mu.g, 21.3 .mu.g, 21.4 .mu.g, 21.5 .mu.g, 21.6 .mu.g,
21.7 .mu.g, 21.8 .mu.g, 21.9 .mu.g, 22.0 .mu.g, 22.1 .mu.g, 22.2
.mu.g, 22.3 .mu.g, 22.4 .mu.g, 22.5 .mu.g, 22.6 .mu.g, 22.7 .mu.g,
22.8 .mu.g, 22.9 .mu.g, 23.0 .mu.g, 23.1 .mu.g, 23.2 .mu.g, 23.3
.mu.g, 23.4 .mu.g, 23.5 .mu.g, 23.6 .mu.g, 23.7 .mu.g, 23.8 .mu.g,
23.9 .mu.g, 24.0 .mu.g, 24.1 .mu.g, 24.2 .mu.g, 24.3 .mu.g, 24.4
.mu.g, 24.5 .mu.g, 24.6 .mu.g, 24.7 .mu.g, 24.8 .mu.g, 24.9 .mu.g,
25.0 .mu.g, 25.1 .mu.g, 25.2 .mu.g, 25.3 .mu.g, 25.4 .mu.g, 25.5
.mu.g, 25.6 .mu.g, 25.7 .mu.g, 25.8 .mu.g, 25.9 .mu.g, 26.0 .mu.g,
26.1 .mu.g, 26.2 .mu.g, 26.3 .mu.g, 26.4 .mu.g, 26.5 .mu.g, 26.6
.mu.g, 26.7 .mu.g, 26.8 .mu.g, 26.9 .mu.g, 27.0 .mu.g, 27.1 .mu.g,
27.2 .mu.g, 27.3 .mu.g, 27.4 .mu.g, 27.5 .mu.g, 27.6 .mu.g, 27.7
.mu.g, 27.8 .mu.g, 27.9 .mu.g, 28.0 .mu.g, 28.1 .mu.g, 28.2 .mu.g,
28.3 .mu.g, 28.4 .mu.g, 28.5 .mu.g, 28.6 .mu.g, 28.7 .mu.g, 28.8
.mu.g, 28.9 .mu.g, 29.0 .mu.g, 29.1 .mu.g, 29.2 .mu.g, 29.3 .mu.g,
29.4 .mu.g, 29.5 .mu.g, 29.6 .mu.g, 29.7 .mu.g, 29.8 .mu.g, 29.9
.mu.g, 30.0 .mu.g, 30.1 .mu.g, 30.2 .mu.g, 30.3 .mu.g, 30.4 .mu.g,
30.5 .mu.g, 30.6 .mu.g, 30.7 .mu.g, 30.8 .mu.g, 30.9 .mu.g, 31.0
.mu.g, 31.1 .mu.g, 31.2 .mu.g, 31.3 .mu.g, 31.4 .mu.g, 31.5 .mu.g,
31.6 .mu.g, 31.7 .mu.g, 31.8 .mu.g, 31.9 .mu.g, 32.0 .mu.g, 32.1
.mu.g, 32.2 .mu.g, 32.3 .mu.g, 32.4 .mu.g, 32.5 .mu.g, 32.6 .mu.g,
32.7 .mu.g, 32.8 .mu.g, 32.9 .mu.g, 33.0 .mu.g, 33.1 .mu.g, 33.2
.mu.g, 33.3 .mu.g, 33.4 .mu.g, 33.5 .mu.g, 33.6 .mu.g, 33.7 .mu.g,
33.8 .mu.g, 33.9 .mu.g, 34.0 .mu.g, 34.1 .mu.g, 34.2 .mu.g, 34.3
.mu.g, 34.4 .mu.g, 34.5 .mu.g, 34.6 .mu.g, 34.7 .mu.g, 34.8 .mu.g,
34.9 .mu.g, 35.0 .mu.g, 35.1 .mu.g, 35.2 .mu.g, 35.3 .mu.g, 35.4
.mu.g, 35.5 .mu.g, 35.6 .mu.g, 35.7 .mu.g, 35.8 .mu.g, 35.9 .mu.g,
36.0 .mu.g, 36.1 .mu.g, 36.2 .mu.g, 36.3 .mu.g, 36.4 .mu.g, 36.5
.mu.g, 36.6 .mu.g, 36.7 .mu.g, 36.8 .mu.g, 36.9 .mu.g, 37.0 .mu.g,
37.1 .mu.g, 37.2 .mu.g, 37.3 .mu.g, 37.4 .mu.g, 37.5 .mu.g, 37.6
.mu.g, 37.7 .mu.g, 37.8 .mu.g, 37.9 .mu.g, 38.0 .mu.g, 38.1 .mu.g,
38.2 .mu.g, 38.3 .mu.g, 38.4 .mu.g, 38.5 .mu.g, 38.6 .mu.g, 38.7
.mu.g, 38.8 .mu.g, 38.9 .mu.g, 39.0 .mu.g, 39.1 .mu.g, 39.2 .mu.g,
39.3 .mu.g, 39.4 .mu.g, 39.5 .mu.g, 39.6 .mu.g, 39.7 .mu.g, 39.8
.mu.g, 39.9 .mu.g, 40.0 .mu.g, 40.1 .mu.g, 40.2 .mu.g, 40.3 .mu.g,
40.4 .mu.g, 40.5 .mu.g, 40.6 .mu.g, 40.7 .mu.g, 40.8 .mu.g, 40.9
.mu.g, 41.0 .mu.g, 41.1 .mu.g, 41.2 .mu.g, 41.3 .mu.g, 41.4 .mu.g,
41.5 .mu.g, 41.6 .mu.g, 41.7 .mu.g, 41.8 .mu.g, 41.9 .mu.g, 42.0
.mu.g, 42.1 .mu.g, 42.2 .mu.g, 42.3 .mu.g, 42.4 .mu.g, 42.5 .mu.g,
42.6 .mu.g, 42.7 .mu.g, 42.8 .mu.g, 42.9 .mu.g, 43.0 .mu.g, 43.1
.mu.g, 43.2 .mu.g, 43.3 .mu.g, 43.4 .mu.g, 43.5 .mu.g, 43.6 .mu.g,
43.7 .mu.g, 43.8 .mu.g, 43.9 .mu.g, 44.0 .mu.g, 44.1 .mu.g, 44.2
.mu.g, 44.3 .mu.g, 44.4 .mu.g, 44.5 .mu.g, 44.6 .mu.g, 44.7 .mu.g,
44.8 .mu.g, 44.9 .mu.g, 45.0 .mu.g, 45.1 .mu.g, 45.2 .mu.g, 45.3
.mu.g, 45.4 .mu.g, 45.5 .mu.g, 45.6 .mu.g, 45.7 .mu.g, 45.8 .mu.g,
45.9 .mu.g, 46.0 .mu.g, 46.1 .mu.g, 46.2 .mu.g, 46.3 .mu.g, 46.4
.mu.g, 46.5 .mu.g, 46.6 .mu.g, 46.7 .mu.g, 46.8 .mu.g, 46.9 .mu.g,
47.0 .mu.g, 47.1 .mu.g, 47.2 .mu.g, 47.3 .mu.g, 47.4 .mu.g, 47.5
.mu.g, 47.6 .mu.g, 47.7 .mu.g, 47.8 .mu.g, 47.9 .mu.g, 48.0 .mu.g,
48.1 .mu.g, 48.2 .mu.g, 48.3 .mu.g, 48.4 .mu.g, 48.5 .mu.g, 48.6
.mu.g, 48.7 .mu.g, 48.8 .mu.g, 48.9 .mu.g, 49.0 .mu.g, 49.1 .mu.g,
49.2 .mu.g, 49.3 .mu.g, 49.4 .mu.g, 49.5 .mu.g, 49.6 .mu.g, 49.7
.mu.g, 49.8 .mu.g, 49.9 .mu.g, and 50 .mu.g. All subranges within
this range are included in the invention.
[0086] The foregoing suggested doses may be adjusted using
conventional dose calculations if the compound is administered via
a different route. Determination of an appropriate dose for
administration by other routes is within the skill of those in the
art in light of the foregoing description and the general knowledge
in the art.
[0087] Delivery of an effective amount of a compound of the
invention may entail delivery of a single dosage form or multiple
unit doses which may be delivered contemporaneously or separate in
time over a designated period, such as 24 hours. A dose of a
compound of the invention (alone or in the form of a composition
comprising the same) may be administered from one to ten times per
day. Typically, a compound of the invention (alone or in the form
of a composition comprising the same) will be administered four,
three, two, or once per day (24 hours).
Compositions
[0088] While it is possible for a compound of the invention to be
administered alone, in some embodiments it is preferable to present
it in the form of a composition, particularly a pharmaceutical
composition (formulation). Thus, in another aspect, the invention
provides compositions, and particularly pharmaceutical compositions
(such as an inhalable pharmaceutical composition) comprising a
pharmaceutically effective amount of a compound of the invention as
an active ingredient, and a pharmaceutically acceptable excipient,
diluent or carrier. The term "active ingredient" as employed herein
refers to any compound of the invention or combination of two or
more compounds of the invention in a pharmaceutical composition.
Also provided are specific embodiments in which a pharmaceutical
composition comprises a pharmaceutically effective amount of a
compound of Formulas (I), (II), (III), and (IV) or a
pharmaceutically acceptable salt thereof, independently or in
combination, and a pharmaceutically acceptable excipient, diluent
or carrier.
[0089] In some embodiments, the pharmaceutical composition
comprises a pharmaceutically effective amount of a compound of
Formulas (I), (II), (III), and (IV) or a pharmaceutically
acceptable salt thereof, independently or in combination, in a
diluent. In separate embodiments, the pharmaceutical composition
comprises a pharmaceutically effective amount of a compound of
Formulas (I), (II), (III), and (IV) or a pharmaceutically
acceptable salt thereof, in hypertonic saline, sterile water, and
hypertonic saline, respectively, wherein the saline concentration
can be as described herein. In one embodiment the saline
concentration is 0.17% w/v and in another it is 2.8% w/v.
[0090] Also provided is a kit comprising (i) a pharmaceutically
effective amount of a compound of Formula (I), (II), (III), and
(IV) or a pharmaceutically acceptable salt thereof; (ii) one or
more pharmaceutically acceptable excipients, carriers, or diluents;
(iii) instructions for administering the compound of group (i) and
the excipients, carriers, or diluents of group (ii) to a subject in
need thereof; and; (iv) a container. A subject in need thereof
includes any subject in need of the methods of treatment described
herein, particularly including a human subject in need thereof.
Further embodiments also comprise an aerosolization device selected
from the group of a nebulizer, including vibrating mesh nebulizers
and jet nebulizers, a dry powder inhaler, including active and
passive dry powder inhalers, and a metered dose inhaler, including
pressurized, dry powder, and soft mist metered dose inhalers.
[0091] In one embodiment a kit comprises (i) from about 10 ng to
about 10 mg of a compound of Formula (I), (II), (III), and (IV) or
a pharmaceutically acceptable salt thereof, per dose; (ii) from
about 1 to about 5 mL of diluent per dose; (iii) instructions for
administering the compound of group (i) and the diluent of group
(ii) to a subject in need thereof; and; (iv) a container. In a
further embodiment, the diluent is from about 1 to about 5 mL of a
saline solution, as described herein, per dose. In a further
embodiment, the diluent is from about 1 to about 5 mL of a
hypotonic saline solution per dose. In another embodiment, the
diluent is from about 1 to about 5 mL of a hypertonic saline
solution per dose. In a still further embodiment, the diluent is
from about 1 to about 5 mL of sterile water per dose.
[0092] Also provided is a kit comprising (i) a solution comprising
a pharmaceutically effective amount of a compound of Formula (I),
(II), (III), and (IV) or a pharmaceutically acceptable salt
thereof; dissolved in a pharmaceutically acceptable diluent; (iii)
instructions for administering the solution of group (i) to a
subject in need thereof; and (iii) a container.
[0093] Also provided is a kit comprising (i) a solution comprising
from about 10 ng to about 10 mg of a compound of Formula (I), (II),
(III), and (IV) or a pharmaceutically acceptable salt thereof;
dissolved in a pharmaceutically acceptable diluent; (iii)
instructions for administering the solution of group i) to a
subject in need thereof; and (iii) a container. In a further
embodiment, the diluent is from about 1 to about 5 mL of a saline
solution, as described herein, per dose.
[0094] Another embodiment comprises a kit comprising (i) a
pharmaceutically effective amount of a compound of Formula (I),
(II), (III), and (IV) or a pharmaceutically acceptable salt
thereof; in a dry powder formulation suitable for inhalation (ii)
optionally, one or more pharmaceutically acceptable excipients or
carriers suitable for inhalation; (iii) instructions for
administering the compound of group (i) and the excipients or
carriers of group (ii) to a subject in need thereof; and; (iv) a
container. In a further embodiment, the kit also comprises a dry
powder inhaler suitable for delivering the dry powder formulation
to a recipient. The dry powder inhaler may be, in additional
embodiments, a single-dose inhaler or a multi-dose inhaler.
[0095] Further embodiments of each of the kits described herein
includes those in which the concentration of the compound of
Formula (I), (II), (III), and (IV) or a pharmaceutically acceptable
salt thereof, per dose, is one of the effective dose ranges
described herein, including (a) from about 0.1 .mu.g to about 1,000
.mu.g; (b) from about 0.5 .mu.g to about 0.5 mg; and (c) from about
0.5 .mu.g to about 50 .mu.g.
[0096] For each of the kits described above there is an additional
embodiment in which the diluent is hypertonic saline of the
concentrations described herein. In another embodiment for each kit
the diluent is hypotonic saline of the concentrations described
herein. In a further embodiment for each kit, the diluent is
sterile water suitable for inhalation.
[0097] The pharmaceutically acceptable excipient(s), diluent(s) or
carrier(s) must be acceptable in the sense of being compatible with
the other ingredients of the formulation and not deleterious to the
recipient thereof. Generally, the pharmaceutically acceptable
excipient(s), diluent(s) or carrier(s) employed in the
pharmaceutical formulation are "non-toxic" meaning that it/they
is/are deemed safe for consumption in the amount delivered in the
formulation and "inert" meaning that it/they does/do not
appreciable react with or result in an undesired effect on the
therapeutic activity of the active ingredient(s). Pharmaceutically
acceptable excipients, diluents and carriers are conventional in
the art and may be selected using conventional techniques, based
upon the desired route of administration. See, REMINGTON'S,
PHARMACEUTICAL SCIENCES, Lippincott Williams & Wilkins;
21.sup.st Ed (May 1, 2005). Preferably, the pharmaceutically
acceptable excipient(s), diluent(s) or carrier(s) are Generally
Regarded As Safe (GRAS) according to the FDA.
[0098] Pharmaceutical compositions according to the invention
include those suitable for oral administration; parenteral
administration, including subcutaneous, intradermal, intramuscular,
intravenous and intraarticular; topical administration, including
topical administration to the skin, eyes, ears, etc.; vaginal or
rectal administration; and administration to the respiratory tract,
including the nasal cavities and sinuses, oral and extrathoracic
airways, and the lungs, including by use of aerosols which may be
delivered by means of various types of dry powder inhalers,
pressurized metered dose inhalers, softmist inhalers, nebulizers,
or insufflators. The most suitable route of administration may
depend upon several factors, including the patient and the
condition or disorder being treated.
[0099] The formulations may be presented in unit dosage form or in
bulk form as for example in the case of formulations to be metered
by an inhaler and may be prepared by any of the methods well known
in the art of pharmacy. Generally, the methods include the step of
bringing the active ingredient into association with the carrier,
diluent or excipient and optionally one or more accessory
ingredients. In general the formulations are prepared by uniformly
and intimately bringing into association the active ingredient with
one or more liquid carriers, diluents or excipients or finely
divided solid carriers, diluents or excipients, or both, and then,
if necessary, shaping the product into the desired formulation.
[0100] Patients can be sensitive to the pH, osmolality, and ionic
content of a nebulized solution. Therefore these parameters should
be adjusted to be compatible with the active ingredient and
tolerable to patients. The most preferred solution or suspension of
active ingredient will contain a chloride concentration >30 mM
at pH 4.5-7.4, preferably 5.0-5.5, and an osmolality of from about
800-1600 mOsm/kg. The pH of the solution can be controlled by
either titration with common acids (hydrochloric acid or sulfuric
acid, for example) or bases (sodium hydroxide, for example) or via
the use of buffers. Commonly used buffers include citrate buffers,
such as citric acid/sodium citrate buffers, acetate buffers, such
as acetic acid/sodium acetate buffers, and phosphate buffers.
Buffer strengths can range from 2 mM to 50 mM.
[0101] Useful acetate, phosphate, and citrate buffers include
sodium acetate, sodium acetate trihydrate, ammonium acetate,
potassium acetate, sodium phosphate, sodium phosphate dibasic,
disodium hydrogen phosphate, potassium dihydrogen phosphate,
potassium hydrogen phosphate, potassium phosphate, sodium citrate,
and potassium citrate. Other buffers which may be utilized include
sodium hydroxide, potassium hydroxide, ammonium hydroxide,
aminomethylpropanol, tromethamine, tetrahydroxypropyl
ethylenediamine, citric acid, acetic acid, hydroxytricarboxylic
acid or a salt thereof, such as a citrate or sodium citrate salt
thereof, lactic acid, and salts of lactic acid including sodium
lactate, potassium lactate, lithium lactate, calcium lactate,
magnesium lactate, barium lactate, aluminum lactate, zinc lactate,
silver lactate, copper lactate, iron lactate, manganese lactate,
ammonium lactate, monoethanolamine, diethanolamine,
triethanolamine, diisopropanolamine, as well as combinations
thereof, and the like.
[0102] Pharmaceutical compositions for topical administration may
be formulated as ointments, creams, suspensions, lotions, powders,
solutions, pastes, gels, sprays, aerosols or oils. Compositions
designed for the treatment of external tissues, for example the
mouth and skin, may be applied as a topical ointment or cream. When
formulated as an ointment, the active ingredient may be employed
with either a paraffinic or a water-miscible ointment base.
Alternatively, the active ingredient may be formulated in a cream
with an oil-in-water cream base or a water-in-oil base.
Compositions for vaginal or rectal administration include
ointments, creams, suppositories and enemas, all of which may be
formulated using conventional techniques.
[0103] In a preferred embodiment of the invention the subject to be
treated by the method of the present invention is not in need of
treatment of mucosal surfaces with a sodium channel blocker. Thus,
in a preferred embodiment of the present invention, the subject to
be treated by the method of the present invention does not have
cystic fibrosis, primary ciliary dyskinesia, chronic bronchitis,
chronic obstructive airway disease, pneumonia or is artificially
ventilated, or any other similar condition. In a particularly
preferred embodiment, the compound of formula (I)-(IV) is topically
administered to the skin, in particular the skin directly in need
of treatment.
Combinations
[0104] The compounds of the invention may be formulated and/or used
in combination with other therapeutically active agents. Examples
of other therapeutically active agents which may be formulated or
used in combination with the compounds of the invention include but
are not limited to osmolytes, anti-inflammatory agents,
anticholinergic agents, .beta.-agonists (including selective
.beta..sub.2-agonists), mineralocorticoid receptor blockers, other
epithelial sodium channel blockers (ENaC receptor blockers), cystic
fibrosis transmembrane conductance regulator (CFTR) modulators,
kinase inhibitors, anti-infective agents, antihistamines,
antibiotics, CD2 inhibitors, corticosteroids, fumarates,
keratinocyte proliferation inhibitors, retinoids, vitamin D
analogues, anti-interleukin-17 monoclonal antibodies,
phosphodiesterase IV inhibitors, sirtuin activators, and
anti-inflammatory agents.
[0105] The present invention thus provides, as another aspect, a
composition comprising an effective amount of a compound of the
invention and one or more other therapeutically active agents
selected from but are not limited to osmolytes, anti-inflammatory
agents, anticholinergic agents, .beta.-agonists (including
selective .beta..sub.2-agonists), mineralocorticoid receptor
blockers, other epithelial sodium channel blockers (ENaC receptor
blockers), cystic fibrosis transmembrane conductance regulator
(CFTR) modulators, kinase inhibitors, anti-infective agents,
antihistamines, antibiotics, CD2 inhibitors, corticosteroids,
fumarates, keratinocyte proliferation inhibitors, retinoids,
vitamin D analogues, anti-interleukin-17 monoclonal antibodies,
phosphodiesterase IV inhibitors, sirtuin activators, and
anti-inflammatory agents.
Experimental Procedures
[0106] Preparation of compounds of Formula (I), (II), (III), and
(IV) are exemplified in U.S. Pat. No. 6,858,614, U.S. Pat. No.
6,858,615, U.S. Pat. No. 6,903,105, U.S. Pat. No. 6,995,160, U.S.
Pat. No. 7,026,325, U.S. Pat. No. 7,030,117, U.S. Pat. No.
7,064,129, U.S. Pat. No. 7,186,833, U.S. Pat. No. 7,189,719, U.S.
Pat. No. 7,192,958, U.S. Pat. No. 7,192,959, U.S. Pat. No.
7,241,766, U.S. Pat. No. 7,247,636, U.S. Pat. No. 7,247,637, U.S.
Pat. No. 7,317,013, U.S. Pat. No. 7,332,496, U.S. Pat. No.
7,345,044, U.S. Pat. No. 7,368,447, U.S. Pat. No. 7,368,450, U.S.
Pat. No. 7,368,451, U.S. Pat. No. 7,375,107, U.S. Pat. No.
7,399,766, U.S. Pat. No. 7,410,968, U.S. Pat. No. 7,820,678, U.S.
Pat. No. 7,842,697, U.S. Pat. No. 7,868,010, U.S. Pat. No.
7,875,619, U.S. Pat. No. 7,956,059, U.S. Pat. No. 8,008,494, U.S.
Pat. No. 8,022,210, U.S. Pat. No. 8,124,607, U.S. Pat. No.
8,143,256, U.S. Pat. No. 8,163,758, U.S. Pat. No. 8,198,286, U.S.
Pat. No. 8,211,895, U.S. Pat. No. 8,324,218, U.S. Pat. No.
8,507,497, U.S. Pat. No. 8,575,176, U.S. Pat. No. 8,669,262, U.S.
Pat. No. 7,956,059, U.S. Pat. No. 8,008,494, U.S. Pat. No.
8,022,210, U.S. Pat. No. 8,124,607, U.S. Pat. No. 8,143,256, U.S.
Pat. No. 8,163,758, U.S. Pat. No. 8,198,286, U.S. Pat. No.
8,211,895, U.S. Pat. No. 8,324,218, U.S. Pat. No. 8,507,497, U.S.
Pat. No. 8,575,176, U.S. Pat. No. 8,669,262, U.S. Pat. No.
7,956,059, U.S. Pat. No. 8,008,494, U.S. Pat. No. 8,846,688, U.S.
Pat. No. 8,022,210, U.S. Pat. No. 8,980,898, U.S. Pat. No.
9,029,382, U.S. Pat. No. 9,072,738, U.S. Pat. No. 9,102,633, U.S.
Pat. No. 9,260,398, U.S. Pat. No. 9,260,398, WO 2014/099673, WO
2014/075108, WO 2014/099705, US Patent Application Publication No.
US2014/0142118-A1, US Patent Application No. US2014/0170244-A1, and
US Patent Application No. US2014/0171447-A1, each of which is
incorporated herein by reference.
In Vitro Measurements of Sodium Channel Blocking Activity and
Reversibility
[0107] One assay used to assess mechanism of action and/or potency
of the compounds of the present invention involves the
determination of lumenal drug inhibition of airway epithelial
sodium currents measured under short circuit current (I.sub.SC)
using airway epithelial monolayers mounted in Using chambers. Cells
obtained from freshly excised human, dog, sheep or rodent airways
are seeded onto porous 0.4 micron Snapwell.TM. Inserts (CoStar),
cultured at air-liquid interface (ALI) conditions in hormonally
defined media, and assayed for sodium transport activity (I.sub.SC)
while bathed in Krebs Bicarbonate Ringer (KBR) in Using chambers.
All test drug additions are to the lumenal bath with half-log dose
addition protocols (from 1.times.10.sup.-11 M to 3.times.10.sup.-5
M), and the cumulative change in I.sub.sc (inhibition) recorded.
All drugs are prepared in dimethyl sulfoxide as stock solutions at
a concentration of 1.times.10.sup.-2 M and stored at -20.degree. C.
Eight preparations are typically run in parallel; two preparations
per run incorporate amiloride and/or benzamil as positive controls.
After the maximal concentration (5.times.10.sup.-5 M) is
administered, the lumenal bath is exchanged three times with fresh,
drug-free KBR solution, and the resultant I.sub.SC measured after
each wash for approximately 5 minutes in duration. Reversibility is
defined as the percent return to the baseline value for sodium
current after the third wash. All data from the voltage clamps are
collected via a computer interface and analyzed off-line.
[0108] Dose-effect relationships for all compounds are considered
and analyzed by the Prism 3.0 program. IC.sub.50 values, maximal
effective concentrations, and reversibility are calculated and
compared to amiloride and benzamil as positive controls. As shown
in Table 1, several examples of compounds of Formula (I)-(IV) are
more potent than amiloride, benzamil, and phenamil.
TABLE-US-00001 TABLE 1 Potency of sodium channel blocking activity.
Compound Potency of Sodium Channel Blockade (IC.sub.50) Fold
Increase in Potency (Relative to Amiloride) Amiloride 781.0 1
Benzamil 46 16.5 Phenamil 116 6.5 Compound 1 7.4 105 Compound 2
10.2 77 Compound 3 3.2 244 Compound 4 17.6 44 Compound 5 6.6 118
Compound 6 5.9 186 ##STR00018## ##STR00019## ##STR00020##
##STR00021## ##STR00022## ##STR00023## ##STR00024##
Pharmacological Assays of Absorption
(1) Apical Disappearance Assay
[0109] Bronchial cells (dog, human, sheep, or rodent cells) are
seeded at a density of 0.25.times.10.sup.6/cm.sup.2 on a porous
Transwell-Col collagen-coated membrane with a growth area of 1.13
cm.sup.2 grown at an air-liquid interface in hormonally defined
media that promotes a polarized epithelium. From 12 to 20 days
after development of an air-liquid interface (ALI) the cultures are
expected to be >90% ciliated, and mucins will accumulate on the
cells. To ensure the integrity of primary airway epithelial cell
preparations, the transepithelial resistance (R.sub.t) and
transepithelial potential differences (PD), which are indicators of
the integrity of polarized nature of the culture, are measured.
Human cell systems are preferred for studies of rates of absorption
from apical surfaces. The disappearance assay is conducted under
conditions that mimic the "thin" films in vivo (.about.25 .mu.l)
and is initiated by adding experimental sodium channel blockers or
positive controls (amiloride, benzamil, phenamil) to the apical
surface at an initial concentration of 10 .mu.M. A series of
samples (5 .mu.l volume per sample) is collected at various time
points, including 0, 5, 20, 40, 90 and 240 minutes. Concentrations
are determined by measuring intrinsic fluorescence of each sodium
channel blocker using a Fluorocount Microplate Flourometer or HPLC.
Quantitative analysis employs a standard curve generated from
authentic reference standard materials of known concentration and
purity. Data analysis of the rate of disappearance is performed
using nonlinear regression, one phase exponential decay (Prism V
3.0). As shown in Table 2, examples of compounds from Formula
(I)-(IV) are absorbed (removed) from the mucosal surface more
slowly than amiloride, benzamil, and phenamil.
TABLE-US-00002 TABLE 2 Epithelial Absorption. Fold Decrease in
Apical Epithelial Uptake Rate Absorption (Relative Compound
(nM/cm.sup.2/min) to Amiloride) Amiloride 2 1.0 Benzamil 6.6 0.3
Phenamil 9.0 0.2 Compound 2 0.2 10.0 Compound 5 0.2 10.0
2. Confocal Microscopy Assay of Amiloride Congener Uptake
[0110] Virtually all amiloride-like molecules fluoresce in the
ultraviolet range. This property of these molecules may be used to
directly measure cellular update using x-z confocal microscopy.
Equimolar concentrations of experimental compounds and positive
controls including amiloride and compounds that demonstrate rapid
uptake into the cellular compartment (benzamil and phenamil) are
placed on the apical surface of airway cultures on the stage of the
confocal microscope. Serial x-z images are obtained with time and
the magnitude of fluorescence accumulating in the cellular
compartment is quantitated and plotted as a change in fluorescence
versus time.
[0111] Primary HBE cells were placed in an apparatus designed to
position transwell membrane supports on a confocal microscope stage
(Leica, Wetzlar, Germany). The glycocalyx and cilia were labeled
with 3 .mu.M wheat germ agglutinin-fluorescein (Molecular Probes,
Eugene, Oreg.) for 45 min at 37.degree. C. to visualize the apical
domain of HBE cell cultures. The autofluorescence of the cells was
acquired prior to apical compound addition. Images were acquired
with a 63.times. water immersion lens in the x-z plane. Benzamil
was added to the mucosal compartment (10 .mu.M; 350 .mu.l), and
images were recorded serially from 0 to 5 min. The data in FIG. 1
shows that benzamil is rapidly taken up by the cells.
[0112] Corneal cells were labeled using calcein-AM dye by
incubating with corneas for 45 minutes at 37.degree. C. in DMEM
media. Equimolar concentrations of 2 microliters of compound 9 or
amiloride were placed on the apical (epithelial) surface of mouse
corneas for one hour at 37.degree. C. Serial x-y images were
obtained one hour post-drug addition by confocal microscopy. The
data shown in FIG. 2 shows an x-z image of the corneas made up from
the composite of the x-y image stack. FIG. 2 shows that amiloride
can fully penetrate the cornea is one hour post-administration, but
Compound 3 remains associated with the apical (epithelial)
surface.
3. Pharmacological Effects and Mechanism of Action of the Drug in
Animals
[0113] The effect of compounds for enhancing mucociliary clearance
(MCC) can be measured using an in vivo model described by Sabater
et al., Journal of Applied Physiology, 1999, pp. 2191-2196,
incorporated herein by reference.
* * * * *