U.S. patent application number 14/464060 was filed with the patent office on 2014-12-04 for tazarotene derivatives.
The applicant listed for this patent is Stiefel Laboratories, Inc.. Invention is credited to Michael J. BISHOP, Xin Frank CAI, Wendy Huang CHERN, Alan COLBORN, Xue GE, Hans HOFLAND, Hansen WONG.
Application Number | 20140357669 14/464060 |
Document ID | / |
Family ID | 43449815 |
Filed Date | 2014-12-04 |
United States Patent
Application |
20140357669 |
Kind Code |
A1 |
GE; Xue ; et al. |
December 4, 2014 |
TAZAROTENE DERIVATIVES
Abstract
The presently described subject matter relates to new
derivatives of tazarotene that also exhibit retinoid activity,
pharmaceutical compositions comprising the derivatives, method of
treating skin disorders with the pharmaceutical compositions, and
process of making the derivatives.
Inventors: |
GE; Xue; (Palo Alto, CA)
; WONG; Hansen; (Sunnyvale, CA) ; CHERN; Wendy
Huang; (Palo Alto, CA) ; HOFLAND; Hans; (Palo
Alto, CA) ; BISHOP; Michael J.; (Research Triangle
Park, NC) ; CAI; Xin Frank; (Palo Alto, CA) ;
COLBORN; Alan; (Research Triangle Park, NC) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Stiefel Laboratories, Inc. |
Wilmington |
DE |
US |
|
|
Family ID: |
43449815 |
Appl. No.: |
14/464060 |
Filed: |
August 20, 2014 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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13383869 |
Jan 13, 2012 |
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PCT/US2010/042225 |
Jul 16, 2010 |
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14464060 |
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61272257 |
Sep 4, 2009 |
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61213794 |
Jul 16, 2009 |
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Current U.S.
Class: |
514/333 ;
514/337; 546/256; 546/280.1 |
Current CPC
Class: |
A61K 31/593 20130101;
A61P 43/00 20180101; A61K 31/4436 20130101; A61K 31/38 20130101;
A61K 45/06 20130101; C07D 409/14 20130101; A61K 31/593 20130101;
A61P 17/08 20180101; A61K 31/327 20130101; A61P 17/06 20180101;
A61P 17/10 20180101; A61P 17/12 20180101; A61K 31/05 20130101; A61K
31/444 20130101; A61K 31/38 20130101; A61K 2300/00 20130101; A61K
2300/00 20130101; A61K 9/0014 20130101; A61K 2300/00 20130101; C07D
409/06 20130101; A61P 17/00 20180101; A61K 31/05 20130101 |
Class at
Publication: |
514/333 ;
546/280.1; 514/337; 546/256 |
International
Class: |
C07D 409/14 20060101
C07D409/14; A61K 31/327 20060101 A61K031/327; A61K 31/444 20060101
A61K031/444; C07D 409/06 20060101 C07D409/06; A61K 31/4436 20060101
A61K031/4436 |
Claims
1. A compound of general formula (I): ##STR00032## wherein n is 0
or 1; R.sup.1 is optionally substituted heterocyclic group, or an
optionally substituted heteroaryl group; and R.sup.2 is hydrogen,
optionally substituted C.sub.1-18 alkyl, optionally substituted
C.sub.2-18 alkenyl, optionally substituted C.sub.2-18 alkynyl,
optionally substituted aryl group, optionally substituted
heterocyclic group, optionally substituted cycloalkyl group, or a
optionally substituted heteroaryl group; or a pharmaceutically
acceptable salt thereof.
2. The compound according to claim 1, wherein n is 1.
3. The compound according to claim 1, wherein R.sup.1 is an
optionally substituted, heteroaryl group.
4. The compound according to claim 3 wherein the heteroaryl is an
optionally substituted pyridyl.
5. The compound according to claim 1, wherein R.sup.1 is an
optionally substituted heterocyclic group.
6. The compound according to claim 5, wherein R.sup.1 is an
optionally substituted optionally substituted pyridinyl, optionally
substituted tetrahydropyranyl, or optionally substituted
piperidinyl.
7. The compound according to claim 1, wherein when R.sup.1 is
optionally substituted one or more times, independently by halogen;
hydroxy; NR.sub.4R.sub.5; hydroxy substituted C.sub.1-6 alkyl;
C.sub.1-6 alkoxy; halosubstituted C.sub.1-6 alkoxy; halosubstituted
C.sub.1-6 alkyl; C.sub.1-6 alkyl; --C(O)OR.sub.6, or
--OC(O)R.sub.6; R.sub.4 and R.sub.5 are independently selected from
hydrogen or C.sub.1-6 alkyl; and R.sub.6 is independently selected
from hydrogen or C.sub.1-6 alkyl.
8. The compound according to claim 7, wherein R.sup.2 is hydrogen
or C.sub.1-6 alkyl.
9. The compound according to claim 8, wherein R.sup.2 is C.sub.1-6
alkyl.
10. The compound according to claim 9, wherein R.sup.2 is
ethyl.
11. The compound according to claim 1 which is: ##STR00033## or a
pharmaceutically acceptable salt thereof.
12. The compound which is
6-[4,4-Dimethyl-2-(pyridine-3-carbonyloxy)thiochroman-6-ylethynyl]nicotin-
ic acid ethyl ester (tazarotene nicotinate).
13. The compound which is
S-6-[4,4-Dimethyl-2-(pyridine-3-carbonyloxy)thiochroman-6-ylethynyl]nicot-
inic acid ethyl ester.
14. The compound which is
R-6-[4,4-Dimethyl-2-(pyridine-3-carbonyloxy)thiochroman-6-ylethynyl]nicot-
inic acid ethyl ester.
15. A pharmaceutical composition comprising a compound according to
claim 1, and one or more pharmaceutically acceptable carriers or
excipients.
16. A pharmaceutical composition comprising a compound according to
claim 11, and one or more pharmaceutically acceptable carriers or
excipients.
17. A pharmaceutical composition comprising a compound according to
claim 12, and one or more pharmaceutically acceptable carriers or
excipients.
18. A pharmaceutical composition comprising a compound according to
claim 13 and one or more pharmaceutically acceptable carriers or
excipients.
19. A pharmaceutical composition comprising a compound according to
claim 14 and one or more pharmaceutically acceptable carriers or
excipients.
20. The pharmaceutical composition according to claim 1, comprising
a second pharmaceutically active agent.
21. The pharmaceutical composition according to claim 14, wherein
the second pharmaceutically active agent is benzoyl peroxide.
Description
FIELD OF THE INVENTION
[0001] The present invention relates to derivatives of
tazarotene.
BACKGROUND OF THE INVENTION
[0002] Tazarotene has the chemical name: ethyl
6-[2-(4,4-dimethylthiochroman-6-yl)-ethynyl nicotinate. Tazarotene
is a retinoid prodrug which is converted to its active form,
tazarotenic acid, by rapid de-esterification in most biological
systems. Tazarotenic acid binds to all three members of the
retinoic acid receptor (RAR) family; RAR.sub..alpha.,
RAR.sub..beta. and RAR.sub..gamma., but has relative selectivity
for RAR.sub..beta. and RAR.sub..gamma., and may modify gene
expression.
[0003] Allergan, Inc. market TAZORAC.RTM. (tazarotene) cream and
TAZORAC.RTM. (tazarotene) gel for the treatment of acne and
psoriasis.
[0004] The treatment of skin disorders using a retinoid or an
antibiotic in combination with benzoyl peroxide is of great
interest to dermatologists. However, this presents challenges to
the formulation chemist insofar as retinoids and antibiotics often
readily degrade in the presence of benzoyl peroxide. Accordingly,
the active ingredients are often not mixed together until
immediately before administration to the patient, or are
administered at different times of the day. Alternatively, the
retinoid or antibiotic might be protected (e.g. by encapsulation)
from reaction with the benzoyl peroxide, or the active ingredients
may be housed in separate chambers of a dual chamber dispenser.
[0005] Thus, there is a need for improved dermatological
compositions containing a combination of active ingredients which
provide the requisite convenience, efficacy and shelf life.
Specifically, a need exists for the identification of stable
retinoids that may be combined with benzoyl peroxide in a
pharmaceutical composition.
SUMMARY OF THE INVENTION
[0006] The present invention is directed to new derivatives of
tazarotene that penetrate the skin and exhibit retinoid-like
activity.
[0007] According to an embodiment, the present invention provides
for a compound of general formula (I):
##STR00001##
[0008] wherein n is 0 or 1;
[0009] R.sup.1 is hydrogen, optionally substituted C.sub.1-18
alkyl, optionally substituted C.sub.2-18 alkenyl, optionally
substituted C.sub.2-18 alkynyl, optionally substituted aryl group,
optionally substituted heterocyclic group, optionally substituted
cycloalkyl group, or an optionally substituted heteroaryl group;
and
[0010] R.sup.2 is hydrogen, optionally substituted C.sub.1-18
alkyl, optionally substituted C.sub.2-18 alkenyl, optionally
substituted C.sub.2-18 alkynyl, optionally substituted aryl group,
optionally substituted heterocyclic group, optionally substituted
cycloalkyl group, or an optionally substituted heteroaryl group; or
a pharmaceutically acceptable salt thereof.
[0011] According to another embodiment, the present invention
provides a compound of formula (II):
##STR00002##
[0012] wherein
[0013] R.sup.3 is hydrogen, optionally substituted C.sub.1-18
alkyl, optionally substituted C.sub.2-18 alkenyl, optionally
substituted C.sub.2-18 alkynyl, optionally substituted aryl group,
optionally substituted heterocyclic group, optionally substituted
cycloalkyl group, or an optionally substituted heteroaryl group; or
a pharmaceutically acceptable salt thereof.
[0014] According to another embodiment, the present invention
provides a pharmaceutical composition comprising a compound of
Formula (I) or (II), or a pharmaceutically acceptable salt thereof,
and one or more pharmaceutically acceptable excipients.
[0015] In a further embodiment, the present invention provides a
method of treating a skin disorder in a subject, the method
comprising administering a composition comprising a therapeutically
effective amount of a compound of Formula (I) or (II), or a
pharmaceutically acceptable salt thereof, and one or more
pharmaceutically acceptable excipients, to a subject in need
thereof.
[0016] In an embodiment, the present invention relates to the use
of a compound of Formula (I) or (II), or a pharmaceutically
acceptable salt thereof, for the preparation of a medicament for
the treatment of a skin disorder.
[0017] In another embodiment, the present invention relates to the
use of a compound of Formula (I) or (II), or a pharmaceutically
acceptable salt thereof, for the treatment of a skin disorder.
BRIEF DESCRIPTION OF DRAWINGS
[0018] FIG. 1 illustrates the degradation of tazarotene into its
degradation products when DUAC.RTM. gel and TAZORAC.RTM. cream are
mixed together. The degradation was observed over 8 hours once
"fresh" samples of DUAC gel and TAZORAC cream were mixed.
[0019] FIG. 2A illustrates the amount of tazarotene sulfoxide and
tazarotenic acid in stability samples (at least 4 replicates and 4
donors (n.gtoreq.17).+-.SEM).
[0020] FIG. 2B illustrates the amount of tazarotene benzoate in
stability samples (at least 4 replicates and 4 donors
(n.gtoreq.17).+-.SEM).
[0021] FIG. 3A illustrates the amount of tazarotene, tazarotene
sulfoxide and tazarotenic acid in the epidermis 2 hours
post-application (at least 4 replicates and 4 donors
(n.gtoreq.17).+-.SEM).
[0022] FIG. 3B illustrates the amount of tazarotene, tazarotene
sulfoxide and tazarotenic acid in the dermis 2 hours
post-application (at least 4 replicates and 4 donors
(n.gtoreq.17).+-.SEM).
[0023] FIG. 4A illustrates the amount of tazarotene, tazarotene
sulfoxide and tazarotenic acid in the epidermis 6 hours
post-application (at least 4 replicates and 4 donors
(n.gtoreq.17).+-.SEM).
[0024] FIG. 4B illustrates the amount of tazarotene, tazarotene
sulfoxide and tazarotenic acid in the dermis 6 hours
post-application (at least 4 replicates and 4 donors
(n.gtoreq.17).+-.SEM).
[0025] FIG. 5A illustrates the amount of tazarotene benzoate in the
epidermis and dermis 2 hours post-application (at least 4
replicates and 4 donors (n.gtoreq.17).+-.SEM).
[0026] FIG. 5B illustrates the amount of tazarotene benzoate in the
epidermis and dermis 6 hours post-application (at least 4
replicates and 4 donors (n.gtoreq.17).+-.SEM).
[0027] FIG. 6 illustrates skin penetration from mixtures of DUAC
gel and TAZORAC cream. The data points represent the cumulative
amount of tazarotene sulfoxide from at least 4 replicates from 4
donors (n.gtoreq.18).+-.SEM.
[0028] FIG. 7 illustrates pro-inflammatory cytokine (IL-1.alpha.
and IL-8) release from SkinEthic RHE cultures following exposure to
various retinoids. Each bar represents the average of duplicate
cultures (.+-.Stdev).
[0029] FIG. 8 illustrates the PMA-induced IL-6 release from A431
cultures following exposure to various retinoids. Each bar
represents the average of triplicate cultures (.+-.Stdev).
[0030] FIG. 9 illustrates the stability of tazarotene, tazarotene
sulfoxide and tazarotene benzoate in rat plasma at room
temperature.
[0031] FIG. 10 illustrates the stability of tazarotene, tazarotene
sulfoxide and tazarotene benzoate in human plasma at room
temperature.
[0032] FIG. 11 illustrates the peak for tazarotene benzoate
measured with a Shimadzu HPLC--Applied Biosystems 4000 QTRAP.
[0033] FIG. 12 illustrates the peak for hydroxytazarotenic acid
measured with a Shimadzu HPLC--Applied Biosystems 4000 QTRAP.
[0034] FIG. 13 illustrates the mass spectra fragmentation of
hydroxytazarotenic acid.
[0035] FIG. 14 illustrates the mass spectra fragmentation of
tazarotenic acid sulfoxide.
[0036] FIG. 15 illustrates the amount of IL-1.alpha. released in
the presence of various retinoids.
[0037] FIG. 16 illustrates the amount of IL-8 released in the
presence of various retinoids.
[0038] FIG. 17 illustrates the biological (retinoid) activity of
various metabolites and analogues of tazarotene benzoate i.e. by
determining gene expression levels for K4. The respective
metabolites and analogues are shown in Table 11 (labeled compounds
1 to 29).
[0039] FIG. 18 illustrates the biological (retinoid) activity of
various metabolites and analogues of tazarotene benzoate i.e. by
determining gene expression levels for K10. The respective
metabolites and analogues are shown in Table 11.
[0040] FIG. 19 illustrates the biological (retinoid) activity of
various metabolites and analogues of tazarotene benzoate i.e. by
determining gene expression levels for K13. The respective
metabolites and analogues are shown in Table 11.
[0041] FIG. 20 illustrates the biological (retinoid) activity of
various metabolites and analogues of tazarotene benzoate i.e. by
determining gene expression levels for K19. The respective
metabolites and analogues are shown in Table 11.
[0042] FIG. 21 illustrates the biological (retinoid) activity of
various metabolites and analogues of tazarotene benzoate i.e. by
determining gene expression levels for filaggrin. The respective
metabolites and analogues are shown in Table 11.
[0043] FIG. 22 illustrates the proposed metabolism of
tazarotene.
[0044] FIG. 23 illustrates the proposed metabolism of tazarotene
benzoate.
[0045] FIGS. 24A, 24B and 24C illustrate the enhanced stability of
tazarotene benzoate and tazarotene nicotinate in the presence of
benzoyl peroxide, relative to tazarotene and hydroxy tazarotenic
acid.
DETAILED DESCRIPTION OF THE INVENTION
[0046] According to an embodiment, the present invention provides a
compound of general formula (I):
##STR00003##
[0047] wherein n is 0 or 1;
[0048] R.sup.1 is hydrogen, optionally substituted C.sub.1-18
alkyl, optionally substituted C.sub.2-18 alkenyl, optionally
substituted C.sub.2-18 alkynyl, optionally substituted aryl group,
optionally substituted heterocyclic group, optionally substituted
C.sub.3-7 cycloalkyl group, or an optionally substituted heteroaryl
group; and
[0049] R.sup.2 is hydrogen, optionally substituted C.sub.1-18
alkyl, optionally substituted C.sub.2-18 alkenyl, optionally
substituted C.sub.2-18 alkynyl, optionally substituted aryl group,
optionally substituted heterocyclic group, optionally substituted
C.sub.3-7 cycloalkyl group, or an optionally substituted heteroaryl
group; or a pharmaceutically acceptable salt thereof.
[0050] Suitably, n is 0 or an integer having a value of 1. In one
embodiment, n is 1. In another embodiment n is 0. In one
embodiment, n is 0, and R.sup.1 is hydrogen.
[0051] Suitably, R.sup.1 is hydrogen, optionally substituted
C.sub.1-18 alkyl, optionally substituted C.sub.2-18 alkenyl,
optionally substituted C.sub.2-18 alkynyl, optionally substituted
aryl group, optionally substituted heterocyclic group, optionally
substituted C.sub.3-7 cycloalkyl group, or an optionally
substituted heteroaryl group.
[0052] Suitably, R.sup.2 is hydrogen, optionally substituted
C.sub.1-18 alkyl, optionally substituted C.sub.2-18 alkenyl,
optionally substituted C.sub.2-18 alkynyl, optionally substituted
aryl group, optionally substituted heterocyclic group, optionally
substituted C.sub.3-7 cycloalkyl group, or an optionally
substituted heteroaryl group.
[0053] When R.sup.1 is an optionally substituted C.sub.1-18 alkyl,
C.sub.2-18 alkenyl, C.sub.2-18 alkynyl, aryl, heterocyclic,
cycloalkyl or heteroaryl group, the group is optionally substituted
one or more times, preferably 1 to 4 times independently by
halogen; hydroxy; NR.sub.4R.sub.5; hydroxy substituted C.sub.1-6
alkyl; C.sub.1-6 alkoxy, such as methoxy or ethoxy; halosubstituted
C.sub.1-6 alkoxy, halosubstituted C.sub.1-6 alkyl, such as
CF.sub.2CF.sub.2H or CF.sub.3; C.sub.1-6 alkyl such as methyl,
ethyl, isopropyl etc.; --C(O)OR.sub.6, or --OC(O)R.sub.6. In one
embodiment, the optional substituents are selected from hydroxy,
NR.sub.4R.sub.5, or hydroxy substituted C.sub.1-6 alkyl, or
--C(O)OR.sub.6.
[0054] Suitably, R.sub.4 and R.sub.5 are independently selected
from hydrogen or C.sub.1-6 alkyl. In one embodiment both R.sub.4
and R.sub.5 are hydrogen.
[0055] Suitably, R.sub.6 is independently selected from hydrogen or
C.sub.1-6 alkyl. In one embodiment R.sub.6 is C.sub.1-6 alkyl. In
another embodiment the C.sub.1-6 alkyl is methyl.
[0056] Suitably, when R.sup.1 or R.sup.2 is an optionally
substituted aryl group, the aryl is an aromatic cyclic hydrocarbon
group of from 5 to 20 carbon atoms having a single ring (e.g.,
phenyl) or multiple condensed (fused) rings, such as naphthyl,
indene or anthryl. In one embodiment the aryl group is an
optionally substituted phenyl, naphthyl or indene. In another
embodiment the R.sup.1 aryl group is an optionally substituted
phenyl or naphthyl. In another embodiment, R.sup.1 is an optionally
substituted phenyl. In another embodiment, R.sup.1 is phenyl or
hydroxy substituted phenyl.
[0057] Suitably, when R.sup.1 or R.sup.2 is an optionally
substituted heteroaryl group, the heteroaryl ring is a monocyclic
five- to seven-membered unsaturated aromatic hydrocarbon ring
containing at least one heteroatom selected from oxygen, nitrogen
and sulfur. Suitable rings include, but are not limited to, furyl,
pyranyl, thienyl, pyrrolyl, oxazolyl, thiazolyl, isoxazolyl,
isothiazolyl, imidazolyl, pyrazolyl, oxadiazolyl, oxathiadiazolyl,
triazolyl, tetrazolyl, thiadiazolyl, pyridyl, pyridazinyl,
pyrimidinyl, pyrazinyl, triazinyl, or uracil. The heteroaryl group
may also include fused aromatic rings comprising at least one
heteroatom selected from oxygen, nitrogen and sulfur. Each of the
fused rings contains five or six ring atoms. Suitable examples of
fused aromatic rings include, but are not limited to, indolyl,
isoindolyl, indazolyl, indolizinyl, azaindolyl, benzoxazolyl,
benzimidazolyl, benzothiazolyl, benzofuranyl, benzothiophenyl,
quinolyl, isoquinolyl, quinazolinyl, quinoxalinyl, naphthyridinyl,
cinnolinyl, purinyl or phthalazinyl.
[0058] In one embodiment, when R.sup.1 is an optionally substituted
heteroaryl group, the heteroaryl is an optionally substituted 2-,
3- or 4-pyridyl or pyranyl ring. In another embodiment the
heteroaryl is an optionally substituted 2-, 3- or 4-pyridyl. In
another embodiment R.sup.1 is an optionally substituted
pyrid-3-yl.
[0059] Suitably, when R.sup.1 or R.sup.2 is an optionally
substituted heterocyclic group, the heterocyclic ring is a
monocyclic three- to seven-membered saturated or non-aromatic,
unsaturated hydrocarbon ring containing at least one heteroatom
selected from nitrogen, oxygen, sulphur or oxidized sulphur
moieties, such as S(O)m, and m is 0 or an integer having a value of
1 or 2. The heterocyclic group may also include fused rings,
saturated or partially unsaturated, and wherein one of the rings
may be aromatic or heteroaromatic. Each of the fused rings may have
from four to seven ring atoms. Suitable examples of heterocyclyl
groups include, but are not limited to, the saturated or partially
saturated versions of the heteroaryl moieties as defined above,
such as tetrahydropyrrole, tetrahydropyran, tetrahydrofuran,
tetrahydrothiophene (including oxidized versions of the sulfur
moiety), azepine, diazepine, aziridinyl, pyrrolinyl, pyrrolidinyl,
2-oxo-1-pyrrolidinyl, 3-oxo-1-pyrrolidinyl, 1,3-benzdioxol-5-yl,
imidazolinyl, imidazolidinyl, indolinyl, pyrazolinyl,
pyrazolidinyl, piperidinyl, piperazinyl, morpholino and
thiomorpholino (including oxidized versions of the sulfur
moiety).
[0060] Suitably, when R.sup.1 is an optionally substituted
heterocyclic group, the heterocyclic is an optionally substituted
piperidinyl, piperazinyl, tetrahydropyranyl or tetrahydrofuranyl
ring. In one embodiment the heterocyclic ring is an optionally
substituted 2-, 3- or 4-piperidinyl. In one embodiment the 2-, 3-
or 4-piperidinyl is substituted by a C.sub.1-6 alkyl. In one
embodiment, the C.sub.1-6 alkyl is methyl. In another embodiment
R.sup.1 is a 4-methylpiperidin-4-yl group.
[0061] In one embodiment, R.sup.1 is an optionally substituted
C.sub.1-18 alkyl. In an embodiment, R.sup.1 is a C.sub.1-18 alkyl
optionally substituted, independently, one or more times by
hydroxy, NR.sub.4R.sub.5, C.sub.1-6 alkoxy, or --C(O)OR.sub.6. In
another embodiment the C.sub.1-18 alkyl is unsubstituted. In
another embodiment R.sup.1 is a C.sub.1-3 alkyl or a C.sub.15
alkyl. In another embodiment R.sup.1 is a C.sub.1-3 alkyl. In
another embodiment the C.sub.1-18 alkyl is substituted by
--C(O)OR.sub.6. In another embodiment, R.sub.6 is a C.sub.1-6
alkyl, preferably methyl.
[0062] In one embodiment, R.sup.1 is an optionally substituted
C.sub.2-18 alkenyl.
[0063] In another embodiment, R.sup.1 is an optionally substituted
aryl, heteroaryl or heterocyclic group.
[0064] In another embodiment, R.sup.1 is selected from an
optionally substituted C.sub.1-18 alkyl, a C.sub.2-18 alkenyl,
optionally substituted phenyl, optionally substituted pyridinyl,
optionally substituted tetrahydropyranyl, or optionally substituted
piperidinyl. In a further embodiment, R.sup.1 is selected from an
optionally substituted phenyl, optionally substituted pyridinyl,
optionally substituted tetrahydropyranyl, or optionally substituted
piperidinyl group.
[0065] When R.sup.2 is an optionally substituted C.sub.1-18 alkyl,
C.sub.2-18 alkenyl, C.sub.2-18 alkynyl, aryl, heterocyclic,
cycloalkyl or heteroaryl group, the group is optionally substituted
one or more times, preferably 1 to 4 times, independently by
halogen; hydroxy; NR.sub.4R.sub.5; hydroxy substituted C.sub.1-6
alkyl; C.sub.1-6 alkoxy, such as methoxy or ethoxy; halosubstituted
C.sub.1-6 alkoxy; halosubstituted C.sub.1-6 alkyl, such as
CF.sub.2CF.sub.2H or CF.sub.3; C.sub.1-6 alkyl such as methyl,
ethyl, isopropyl, etc.; --C(O)OR.sub.6 or --OC(O)R.sub.6.
[0066] In one embodiment R.sup.2 is hydrogen or optionally
substituted C.sub.1-18 alkyl. In an embodiment, R.sup.2 is hydrogen
or optionally substituted C.sub.1-6 alkyl. In another embodiment,
R.sup.2 is hydrogen. In another embodiment, R.sup.2 is C.sub.1-6
alkyl. According to a further embodiment, R.sup.2 is ethyl.
[0067] According to one embodiment, n is 1, R.sup.1 is phenyl and
R.sup.2 is hydrogen or C.sub.1-6 alkyl. In another embodiment, n is
1, R.sup.1 is phenyl and R.sup.2 is hydrogen. This compound is
known as
6-(2-(2-benzoyloxy-4,4-dimethylthiochroman-6-yl)ethynyl)nicotinic
acid, and is also described herein as tazarotenic acid
benzoate.
[0068] In another embodiment, n is 1, R.sup.1 is phenyl and R.sup.2
is C.sub.1-6 alkyl. In one embodiment, the C.sub.1-6 alkyl is
ethyl. This compound is known as
6-(2-(2-benzoyloxy-4,4-dimethylthiochroman-6-yl)ethynyl)nicotinic
acid, ethyl ester, and is described herein as tazarotene
benzoate.
[0069] In another embodiment, the compound is
(S)-6-(2-(2-benzoyloxy-4,4-dimethylthiochroman-6-yl)ethynyl)nicotinic
acid, ethyl ester. In another embodiment, the compound is
(R)-6-(2-(2-benzoyloxy-4,4-dimethylthiochroman-6-yl)ethynyl)nicotinic
acid, ethyl ester.
[0070] According to a further embodiment, n is 0, R.sup.1 is
hydrogen and R.sup.2 is hydrogen or C.sub.1-6 alkyl. In an
embodiment, R.sup.2 is hydrogen. This compound is
6-((2-hydroxy-4,4-dimethylthiochroman-6-yl)ethynyl)nicotinic acid,
and is also described herein as hydroxy tazarotenic acid.
[0071] In another embodiment, n is 0, R.sup.1 is hydrogen and
R.sup.2 is C.sub.1-6 alkyl. According to a further embodiment,
C.sub.1-6 alkyl is ethyl. This compound is ethyl
6-[(2-hydroxy-4,4-dimethyl-3,4-dihydro-2-thiochromen-6-yl)ethyynyl]pyridi-
ne-3-carboxylate, and is also described herein as hydroxy
tazarotene.
[0072] The compounds of the present invention may be in the form of
and/or may be administered as a pharmaceutically acceptable salt.
For a review on suitable salts see Berge et al., J. Pharm. Sci.,
1977, 66, 1-19.
[0073] Typically, a pharmaceutical acceptable salt may be readily
prepared by using a desired acid or base as appropriate. The salt
may precipitate from solution and be collected by filtration or may
be recovered by evaporation of the solvent.
[0074] According to an embodiment, a compound of Formula (I), is
selected from: [0075] (i)
6-[4,4-dimethyl-2-(pyridine-3-carbonyloxy)thiochroman-6-ylethynyl]nicotin-
ic acid ethyl ester, [0076] (ii)
(S)-6-[4,4-dimethyl-2-(pyridine-3-carbonyloxy)thiochroman-6-ylethynyl]nic-
otinic acid ethyl ester, [0077] (iii)
(R)-6-[4,4-dimethyl-2-(pyridine-3-carbonyloxy)thiochroman-6-ylethynyl]nic-
otinic acid ethyl ester, [0078] (iv) Ethyl
6-[2-palmitoyl-4,4-dimethyl-3,4-dihydro-2-thiochromen-6-yl)ethynyl]pyridi-
ne-3-carboxylate, [0079] (v)
6-[2-(2-Hydroxy-acetoxy)-4,4-dimethyl-thiochroman-6-ylethynyl]-nicotinic
acid ethyl ester, [0080] (vi) Ethyl
6-[(2-(2-methoxyacetyl)-4,4-dimethyl-3,4-dihydro-2-thiochromen-6-yl)ethyn-
yl]pyridine-3-carboxylate, [0081] (vii) Ethyl
6-[(2-acetyl-4,4-dimethyl-3,4-dihydro-2-thiochromen-6-yl)ethynyl]pyridine-
-3-carboxylate, [0082] (viii) Ethyl
6-[(2-n-butyryloxyl-4,4-dimethyl-3,4-dihydro-2-thiochromen-6-yl)ethynyl]p-
yridine-3-carboxylate, [0083] (ix) Ethyl
6-[(2-lauroyl-4,4-dimethyl-3,4-dihydro-2-thiochrornen-6-yl)ethynyl]pyridi-
ne-3-carboxylate, [0084] (x) Ethyl
6-[(2-isobutyryloxy-4,4-dimethyl-3,4-dihydro-2-thiochrornen-6-yl)ethynyl]-
pyridine-3-carboxylate, [0085] (xi) Ethyl
6-[(2-linoeoyll-4,4-dimethyl-3,4-dihydro-2-thiochrornen-6-yl)ethynyl]pyri-
dine-3-carboxylate, [0086] (xii) Ethyl
6-[(2-linleolyl-4,4-dimethyl-3,4-dihydro-2-thiochrornen-6-yl)ethynyl]pyri-
dine-3-carboxylate, [0087] (xiii) Ethyl
6-[(2-(N-methyl-4-piperidinylcarboxy-4,4-dimethyl-3,4-dihydro-2-thiochror-
nen-6-yl)ethynyl]pyridine-3-carboxylate, [0088] (xiv) Ethyl
6-[(2-propionyl-4,4-dimethyl-3,4-dihydro-2-thiochrornen-6-yl)ethynyl]pyri-
dine-3-carboxylate, [0089] (xv) Ethyl
6-[(2-salicylicyl-4,4-dimethyl-3,4-dihydro-2-thiochrornen-6-yl)ethynyl]py-
ridine-3-carboxylate, [0090] (xvi) Ethyl
6-[(2-(4-pyranyloxy-4,4-dimethyl-3,4-dihydro-2-thiochrornen-6-yl)ethynyl]-
pyridine-3-carboxylate, [0091] (xvii) Ethyl
6-[(2-monomethyladopyl-4,4-dimethyl-3,4-dihydro-2-thiochrornen-6-yl)ethyn-
yl]pyridine-3-carboxylate, [0092] (xviii) Ethyl
6-[(2-(3-monomethylazelauate-4,4-dimethyl-3,4-dihydro-2-thiochrornen-6-yl-
)ethynyl]pyridine-3-carboxylate, and [0093] (xix)
6-[2-((S)-2-Amino-3-methyl-butyryloxy)-4,4-dimethyl-thiochroman-6-ylethyn-
yl]-nicotinic acid ethyl ester; or a pharmaceutically acceptable
salt thereof.
[0094] Suitably, the compound of Formula (I) is
6-[4,4-dimethyl-2-(pyridine-3-carbonyloxy)thiochroman-6-ylethynyl]nicotin-
ic acid ethyl ester, or a pharmaceutically acceptable salt
thereof.
[0095] Suitably, the compound of Formula (I) is
(S)-6-[4,4-dimethyl-2-(pyridine-3-carbonyloxy)thiochroman-6-ylethynyl]nic-
otinic acid ethyl ester, or a pharmaceutically acceptable salt
thereof.
[0096] Suitably, the compound of Formula (I) is
(R)-6-[4,4-dimethyl-2-(pyridine-3-carbonyloxy)thiochroman-6-ylethynyl]nic-
otinic acid ethyl ester, or a pharmaceutically acceptable salt
thereof.
[0097] Suitably, the compound of Formula (I) is ethyl
6-[2-palmitoyl-4,4-dimethyl-3,4-dihydro-2-thiochromen-6-yl)ethynyl]pyridi-
ne-3-carboxylate, or a pharmaceutically acceptable salt
thereof.
[0098] Suitably, the compound of Formula (I) is
6-[2-(2-Hydroxy-acetoxy)-4,4-dimethyl-thiochroman-6-ylethynyl]-nicotinic
acid ethyl ester, or a pharmaceutically acceptable salt
thereof.
[0099] Suitably, the compound of Formula (I) is ethyl
6-[2-(2-methoxyacetyl)-4,4-dimethyl-3,4-dihydro-2-thiochromen-6-yl)ethyny-
l]pyridine-3-carboxylate, or a pharmaceutically acceptable salt
thereof.
[0100] Suitably, the compound of Formula (I) is ethyl
6-[(2-acetyl-4,4-dimethyl-3,4-dihydro-2-thiochromen-6-yl)ethynyl]pyridine-
-3-carboxylate, or a pharmaceutically acceptable salt thereof.
[0101] Suitably, the compound of Formula (I) is ethyl
6-[(2-n-butyryloxyl-4,4-dimethyl-3,4-dihydro-2-thiochromen-6-yl)ethynyl]p-
yridine-3-carboxylate, or a pharmaceutically acceptable salt
thereof.
[0102] Suitably, the compound of Formula (I) is ethyl
6-[(2-lauroyl-4,4-dimethyl-3,4-dihydro-2-thiochrornen-6-yl)ethynyl]pyridi-
ne-3-carboxylate, or a pharmaceutically acceptable salt thereof.
Suitably, the compound of Formula (I) is ethyl
6-[(2-isobutyryloxy-4,4-dimethyl-3,4-dihydro-2-thiochrornen-6-yl)ethynyl]-
pyridine-3-carboxylate, or a pharmaceutically acceptable salt
thereof.
[0103] Suitably, the compound of Formula (I) is ethyl
6-[2-linoeoyll-4,4-dimethyl-3,4-dihydro-2-thiochrornen-6-yl)ethynyl]pyrid-
ine-3-carboxylate, or a pharmaceutically acceptable salt
thereof.
[0104] Suitably, the compound of Formula (I) is ethyl
6-[(2-linleolyl-4,4-dimethyl-3,4-dihydro-2-thiochrornen-6-yl)ethynyl]pyri-
dine-3-carboxylate, or a pharmaceutically acceptable salt
thereof.
[0105] Suitably, the compound of Formula (I) is ethyl
6-[(2-(N-methyl-4-piperidinylcarboxy-4,4-dimethyl-3,4-dihydro-2-thiochror-
nen-6-yl)ethynyl]pyridine-3-carboxylate, or a pharmaceutically
acceptable salt thereof.
[0106] Suitably, the compound of Formula (I) is ethyl
6-[(2-propionyl-4,4-dimethyl-3,4-dihydro-2-thiochrornen-6-yl)ethynyl]pyri-
dine-3-carboxylate, or a pharmaceutically acceptable salt
thereof.
[0107] Suitably, the compound of Formula (I) is ethyl
6-[(2-salicylicyl-4,4-dimethyl-3,4-dihydro-2-thiochrornen-6-yl)ethynyl]py-
ridine-3-carboxylate, or a pharmaceutically acceptable salt
thereof.
[0108] Suitably, the compound of Formula (I) is ethyl
6-[(2-(4-pyranyloxy-4,4-dimethyl-3,4-dihydro-2-thiochrornen-6-yl)ethynyl]-
pyridine-3-carboxylate, or a pharmaceutically acceptable salt
thereof.
[0109] Suitably, the compound of Formula (I) is ethyl
6-[2-monomethyladopyl-4,4-dimethyl-3,4-dihydro-2-thiochrornen-6-yl)ethyny-
l]pyridine-3-carboxylate, or a pharmaceutically acceptable salt
thereof.
[0110] Suitably, the compound of Formula (I) is ethyl
6-[2-(3-monomethylazelauate-4,4-dimethyl-3,4-dihydro-2-thiochrornen-6-yl)-
ethynyl]pyridine-3-carboxylate, or a pharmaceutically acceptable
salt thereof.
[0111] Suitably, the compound of Formula (I) is
6-[2-((S)-2-Amino-3-methyl-butyryloxy)-4,4-dimethyl-thiochroman-6-ylethyn-
yl]-nicotinic acid ethyl ester, or a pharmaceutically acceptable
salt thereof.
[0112] According to another embodiment, the compound of Formula (I)
is selected from the group consisting of: [0113] Ethyl
6-[2-propionyl-4,4-dimethyl-3,4-dihydro-2-thiochrornen-6-yl)ethynyl]pyrid-
ine-3-carboxylate; [0114] Ethyl
6-[(2-(N-methyl-4-piperidinylcarboxy-4,4-dimethyl-3,4-dihydro-2-thiochror-
nen-6-yl)ethynyl]pyridine-3-carboxylate; [0115]
6-((4,4-dimethyl-2-oxothiochroman-6-yl)ethynyl)nicotinic acid;
[0116]
6-[2-((S)-2-Amino-3-methyl-butyryloxy)-4,4-dimethyl-thiochroman-6-ylethyn-
yl]-nicotinic acid ethyl ester; [0117]
6-[2-(2-Hydroxy-acetoxy)-4,4-dimethyl-thiochroman-6-ylethynyl]-nicotinic
acid ethyl ester; and [0118] Ethyl
6-[2-monomethyladopyl-4,4-dimethyl-3,4-dihydro-2-thiochrornen-6-yl)ethyny-
l]pyridine-3-carboxylate; or a pharmaceutically acceptable salt
thereof.
[0119] In another aspect, the invention provides a compound of the
formula:
##STR00004##
[0120] wherein
[0121] R.sup.3 is hydrogen, optionally substituted C.sub.1-18
alkyl, optionally substituted C.sub.2-18 alkenyl, optionally
substituted C.sub.2-18 alkynyl, optionally substituted aryl group,
optionally substituted heterocyclic group, optionally substituted
C.sub.3-7 cycloalkyl group, or an optionally substituted heteroaryl
group; or a pharmaceutically acceptable salt thereof.
[0122] When R.sup.3 is an optionally substituted C.sub.1-18 alkyl,
C.sub.2-18 alkenyl, C.sub.2-18 alkynyl, aryl, heterocyclic,
cycloalkyl or heteroaryl group, the group is optionally substituted
one or more times, preferably 1 to 4 times independently by
halogen; hydroxy; NR.sub.4R.sub.5; hydroxy substituted C.sub.1-6
alkyl; C.sub.1-6 alkoxy, such as methoxy or ethoxy; halosubstituted
C.sub.1-6 alkoxy; halosubstituted C.sub.1-6 alkyl, such as
CF.sub.2CF.sub.2H or CF.sub.3; C.sub.1-6 alkyl such as methyl,
ethyl, isopropyl, etc.; --C(O)OR.sub.6 or --OC(O)R.sub.6.
[0123] Suitably, R.sub.4 and R.sub.5 are independently selected
from hydrogen or C.sub.1-6 alkyl. In one embodiment both R.sub.4
and R.sub.5 are hydrogen.
[0124] Suitably, R.sub.6 is independently selected from hydrogen or
C.sub.1-6 alkyl. In one embodiment R.sub.6 is C.sub.1-6 alkyl. In
another embodiment the C.sub.1-6 alkyl is methyl.
[0125] When R.sup.3 is an optionally substituted aryl group, it is
as defined above for R.sup.1 or R.sup.2 in Formula (I) herein.
[0126] When R.sup.3 is an optionally substituted heteroaryl group,
it is as defined above for R.sup.1 or R.sup.2 in Formula (I)
herein.
[0127] When R.sup.3 is an optionally substituted heterocyclic
group, it is as defined above for R.sup.1 or R.sup.2 in Formula (I)
herein.
[0128] In one embodiment, R.sup.3 is hydrogen or an optionally
substituted C.sub.1-6 alkyl.
[0129] In one embodiment, R.sup.3 is hydrogen. This compound is
6-((4,4-dimethyl-2-oxothiochroman-6-yl)ethynyl)nicotinic acid, and
is also described herein as keto tazarotenic acid.
[0130] According to another embodiment, R.sup.3 is C.sub.1-6 alkyl.
In another embodiment, the C.sub.1-6 alkyl is ethyl. This compound
is ethyl 6-((4,4-dimethyl-2-oxothiochroman-6-yl)ethynyl)nicotinate,
and is also described herein as keto tazarotene.
Tazarotene Benzoate
[0131] According to a particular embodiment, the compound is
6-(2-(2-benzoyloxy-4,4-dimethylthiochroman-6-yl)ethynyl)nicotinic
acid, ethyl ester (i.e. tazarotene benzoate). Tazarotene benzoate
is formed by combining tazarotene and benzoyl peroxide. This novel
compound penetrates the skin and has retinoid-like activity. The S
and R enantiomers have been isolated and characterized, and
described herein. A range of analogues and metabolites of
tazarotene benzoate have also been isolated, synthesized and
characterized as is further described.
Active Metabolites of Tazarotene
[0132] Known metabolites of tazarotene i.e. tazarotene sulfoxide
and tazarotenic acid, have been shown to penetrate the skin.
However, other known metabolites of tazarotene, namely ethyl
6-((4,4-dimethyl-1,1-dioxidothiochroman-6-yl)ethynyl)nicotinate
(tazarotene sulfone),
6-((4,4-dimethyl-1-oxidothiochroman-6-yl)ethynyl)nicotinic acid
(tazarotenic acid sulfoxide), and
6-((4,4-dimethyl-1,1-dioxidothiochroman-6-yl)ethynyl)nicotinic acid
(tazarotenic acid sulfone), which were previously thought by others
to have little or no retinoid activity, have been discovered to
exert retinoid like activity (FIG. 22 and Example 3).
[0133] Accordingly, the present invention also relates to a method
of treating a skin disorder in a subject, the method comprising
administering a composition comprising a therapeutically effective
amount of a compound selected from the group consisting of ethyl
6-((4,4-dimethyl-1,1-dioxidothiochroman-6-yl)ethynyl)nicotinate,
6-((4,4-dimethyl-1-oxidothiochroman-6-yl)ethynyl)nicotinic acid and
6-((4,4-dimethyl-1,1-dioxidothiochroman-6-yl)ethynyl)nicotinic
acid, or a pharmaceutically acceptable salt thereof, along with one
or more pharmaceutically acceptable excipients, to a subject in
need thereof.
[0134] In an embodiment, the present invention relates to the use
of a compound selected from the group consisting of ethyl
6-((4,4-dimethyl-1,1-dioxidothiochroman-6-yl)ethynyl)nicotinate,
6-((4,4-dimethyl-1-oxidothiochroman-6-yl)ethynyl)nicotinic acid and
6-((4,4-dimethyl-1,1-dioxidothiochroman-6-yl)ethynyl)nicotinic
acid, or a pharmaceutically acceptable salt thereof, in the
preparation of a medicament for the treatment of a skin
disorder.
[0135] In another embodiment, the invention relates to the use of a
compound selected from the group consisting of ethyl
6-((4,4-dimethyl-1,1-dioxidothiochroman-6-yl)ethynyl)nicotinate,
6-((4,4-dimethyl-1-oxidothiochroman-6-yl)ethynyl)nicotinic acid and
6-((4,4-dimethyl-1,1-dioxidothiochroman-6-yl)ethynyl)nicotinic
acid, or a pharmaceutically acceptable salt thereof, for the
treatment of a skin disorder.
[0136] In yet another embodiment, the invention relates to a
pharmaceutical composition comprising a compound selected from the
group consisting of ethyl
6-((4,4-dimethyl-1,1-dioxidothiochroman-6-yl)ethynyl)nicotinate,
6-((4,4-dimethyl-1-oxidothiochroman-6-yl)ethynyl)nicotinic acid and
6-((4,4-dimethyl-1,1-dioxidothiochroman-6-yl)ethynyl)nicotinic
acid, or a pharmaceutically acceptable salt thereof, along with one
or more pharmaceutically acceptable excipients.
Pharmaceutical Compositions
[0137] According to an embodiment, the present invention provides a
pharmaceutical composition comprising a compound of Formula (I) or
(II), or a pharmaceutically acceptable salt thereof, and one or
more pharmaceutically acceptable carriers or excipients.
[0138] In one embodiment, the pharmaceutical composition comprises
a second pharmaceutically active agent.
[0139] In one embodiment, the second pharmaceutically active agent
is selected from the group consisting benzoyl peroxide, an
antibiotic, a corticosteroid and a vitamin D analogue.
[0140] In an embodiment, the second pharmaceutically active agent
is benzoyl peroxide.
[0141] In another embodiment, the second pharmaceutically active
agent is an antibiotic, such as clindamycin or a pharmaceutically
acceptable salt thereof (e.g. clindamycin phosphate).
[0142] In another embodiment, the second pharmaceutically active
agent is a corticosteroid. Suitable corticosteroids include, but
are not limited to, alclometasone dipropionate, amcinonide,
beclomethasone dipropionate, betamethasone benzoate, betamethasone
dipropionate, betamethasone valerate, budesonide, clobetasol
propionate, clobetasone butyrate, cortisone acetate, desonide,
desoximetasone, diflorasone diacetate, diflucortolone valerate,
fluclorolone acetonide, flumethasone pivalate, fluocinolone
acetonide, fluocinonide, fluocortin butyl, fluocortolone,
fluprednidene acetate, flurandrenolide, flurandrenolone, fluticas
one propionate, halcinonide, halobetasol propionate,
hydrocortisone, hydrocortisone acetate, hydrocortisone butyrate,
hydrocortisone propionate, hydrocortisone valerate,
methylprednisolone acetate, mometasone furoate, pramoxine
hydrochloride, prednisone acetate, prednisone valerate,
triamcinolone acetonide, prednicarbate, and pharmaceutically
acceptable salts thereof.
[0143] In another embodiment, the second pharmaceutically active
agent is a vitamin D analogue. Suitable vitamin D analogues
include, but are not limited to, calcidiol, calcitriol,
calcipotriene, paricalcitol, 22-oxacolcitriol, dihydrotachysterol,
calciferol, and pharmaceutically acceptable salts thereof.
[0144] In an embodiment, the invention provides a pharmaceutical
composition comprising a compound of Formula (I) or (II) or a
pharmaceutically acceptable salt thereof and a second active agent,
wherein the stability of the compound of Formula (I) or (II) is
superior to the stability of tazarotene in a pharmaceutical
composition comprising tazarotene and the second active agent. In
an embodiment, the compound of Formula (I) or (II) is tazarotene
benzoate or tazarotene nicotinate. According to a particular
embodiment, the second active agent is benzoyl peroxide. Suitably,
the amounts present in the composition are therapeutically
effective amounts for the treatment of skin disorders.
[0145] The compounds of the present invention may be formulated as
pharmaceutical compositions and administered orally, topically,
dermally, parenterally, by injection, by pulmonary or nasal
delivery, sublingually, rectally or vaginally. According to a
particular embodiment, the pharmaceutical composition is adapted
for oral or topical administration. The term "administered by
injection" includes intravenous, intraarticular, intramuscular
(e.g. by depot injection where the active compounds are released
slowly into the blood from the depot and carried from there to the
target organs), intraperitoneal, intradermal, subcutaneous, and
intrathecal injections, as well as use of infusion techniques.
Dermal administration may include topical or transdermal
administration. Transdermal administration can be accomplished by
suitable patches, solutions, emulsions, suspensions, ointments,
pastes, powders, foams, creams, lotions or gels as generally known
in the art, specifically designed for the transdermal delivery of
active agents, optionally in the presence of specific permeability
enhancers. Similarly, topical administration can be accomplished by
a solution, emulsion, suspension, ointment, paste, powder, foam,
cream, lotion or gel. In a particular embodiment, topical
administration is accomplished with an aerosol foam.
[0146] Exemplary pharmaceutically acceptable excipients include
abrasives, acidifying agents, adhesives, adsorbents, alkalizing
agents, antibacterial agents, anticaking agents, antioxidants,
binding agents, buffering agents, bulking agents, chelating agents,
coating agents, coloring agents, complexing agents, controlled
release agents, cooling agents, detergents, diluents, dispersing
agents, dissolution enhancers, emollients, emulsifying agents,
emulsion stabilizers, film forming agents, gelling agents,
glidants, humectants, lubricants, opacifying agents, penetration
enhancers, pH adjusting agents, pigments, plasticizers,
preservatives, propellants, sequestering agents, solubilizing
agents, solvents, surfactants, suspending agents, thickening
agents, viscosity increasing agents and wetting agents.
[0147] The pharmaceutical composition may be formulated using
methods known in the art as immediate release, sustained release,
delayed release, pulsatile release or two step release, for
example.
[0148] The dosage of the active agent in the pharmaceutical
composition will depend upon a variety of factors, including but
not limited to, the activity of the active agent, the condition
being treated, the nature of the pharmaceutical composition, the
mode of administration and the age, body weight, general health and
gender of the patient.
Methods of Use
[0149] According to an embodiment, the present invention relates to
a method of treating a skin disorder. The method comprises
administering to a subject a pharmaceutical composition comprising
a therapeutically effective amount of a compound of Formula (I) or
(II), or a pharmaceutically acceptable salt thereof, along with one
or more pharmaceutically acceptable excipients, to a subject in
need thereof.
[0150] Another to an embodiment, the skin disorder is acne,
psoriasis, seborrhea, ichthyosis or keratosis pilaris. According to
a particular embodiment, the skin disorder is acne or
psoriasis.
DEFINITIONS
[0151] The term "halo" or "halogens" is used herein to mean the
halogens, chloro, fluoro, bromo and iodo.
[0152] The term "alkyl" is used herein to mean an aliphatic
hydrocarbon group which may be straight or branched chain having
about 1 to about 18 carbon atoms in the chain. A preferred
embodiment is an alkyl group having from 1 to about 6 carbon atoms.
Alkyl as defined herein may be optionally substituted with a
designated number of substituents.
[0153] The term "unsaturated" refers to the presence of one or more
double or triple bonds between carbon atoms of a hydrocarbon
chain.
[0154] The term "alkenyl" is used herein to mean a hydrocarbon
chain of a specified number of carbon atoms of either a straight or
branched configuration and having at least one carbon-carbon double
bond, which may occur at any point along the chain, such as
ethenyl, propenyl, butenyl, pentenyl, vinyl, alkyl or 2-butenyl.
Alkenyl as defined herein may be optionally substituted with a
designated number of substituents.
[0155] The term "alkynyl" is used herein to mean a hydrocarbon
chain of a specified number of carbon atoms of either a straight or
branched configuration and having at least one carbon-carbon triple
bond, which may occur at any point along the chain. An example of
an alkynyl is acetylene. Alkynyl as defined herein may be
optionally substituted with a designated number of
substituents.
[0156] The term "cycloalkyl" is used herein to refer to cyclic
radicals, such as a non-aromatic hydrocarbon ring containing a
specified number of carbon atoms. For example, C.sub.3-7 cycloalkyl
means a non-aromatic ring containing at least three, and at most
seven, ring carbon atoms. Representative examples of "cycloalkyl"
as used herein include, but are not limited to, cyclopropyl,
cyclobutyl, cyclopentyl, cyclohexyl and cycloheptyl.
[0157] The term "aryl" is used herein to mean an aromatic cyclic
hydrocarbon group of from 5 to 20 carbon atoms having a single ring
(e.g., phenyl) or multiple condensed (fused) rings (e.g. naphthyl
or anthryl). Preferred aryl groups include phenyl and naphthyl.
[0158] The terms "heteroaryl ring", "heteroaryl moiety", and
"heteroaryl" are used herein to mean a monocyclic five- to
seven-membered unsaturated aromatic hydrocarbon ring containing at
least one heteroatom selected from oxygen, nitrogen and sulfur.
Examples of heteroaryl rings include, but are not limited to,
furyl, pyranyl, thienyl, pyrrolyl, oxazolyl, thiazolyl, isoxazolyl,
isothiazolyl, imidazolyl, pyrazolyl, oxadiazolyl, oxathiadiazolyl,
triazolyl, tetrazolyl, thiadiazolyl, pyridyl, pyridazinyl,
pyrimidinyl, pyrazinyl, triazinyl, and uracil. The terms
"heteroaryl ring", "heteroaryl moiety", and "heteroaryl" shall also
be used herein to refer to fused aromatic rings comprising at least
one heteroatom selected from oxygen, nitrogen and sulfur. Each of
the fused rings may contain five or six ring atoms. Examples of
fused aromatic rings include, but are not limited to, indolyl,
isoindolyl, indazolyl, indolizinyl, azaindolyl, benzoxazolyl,
benzimidazolyl, benzothiazolyl, benzofuranyl, benzothiophenyl,
quinolyl, isoquinolyl, quinazolinyl, quinoxalinyl, naphthyridinyl,
cinnolinyl, purinyl and phthalazinyl.
[0159] The terms "heterocyclic rings", "heterocyclic moieties" and
"heterocyclyl" are used herein to mean a monocyclic three- to
seven-membered saturated or non-aromatic, unsaturated hydrocarbon
ring containing at least one heteroatom selected from nitrogen,
oxygen, sulphur or oxidized sulphur moieties, such as S(O).sub.m,
and m is 0 or an integer having a value of 1 or 2. The terms
"heterocyclic rings", "heterocyclic moieties", and "heterocyclyl"
shall also refer to fused rings, saturated or partially
unsaturated, and wherein one of the rings may be aromatic, or
heteroaromatic. Each of the fused rings may have from four to seven
ring atoms. Examples of heterocyclyl groups include, but are not
limited to, the saturated or partially saturated versions of the
heteroaryl moieties as defined above, such as tetrahydropyrrole,
tetrahydropyran, tetrahydrofuran, tetrahydrothiophene (including
oxidized versions of the sulfur moiety), azepine, diazepine,
aziridinyl, pyrrolinyl, pyrrolidinyl, 2-oxo-1-pyrrolidinyl,
3-oxo-1-pyrrolidinyl, 1,3-benzdioxol-5-yl, imidazolinyl,
imidazolidinyl, indolinyl, pyrazolinyl, pyrazolidinyl, piperidinyl,
piperazinyl, morpholino and thiomorpholino (including oxidized
versions of the sulfur moiety).
[0160] The terms "arylalkyl" or "heteroarylalkyl" or
"heterocyclicalkyl" are used herein to mean a C.sub.1-4 alkyl (as
defined above) attached to an aryl, heteroaryl or heterocyclic
moiety (as also defined above) unless otherwise indicated.
[0161] "Heteroatom" refers to a nitrogen, sulfur or oxygen atom,
wherein the nitrogen and sulfur atoms may be optionally
oxidized.
[0162] The phrases an "effective amount" or "an amount effective
to" or a "therapeutically effective amount" of a pharmaceutically
active agent or ingredient, are used herein to refer to an amount
of the pharmaceutically active agent sufficient to have a
therapeutic effect upon administration. Effective amounts of the
pharmaceutically active agent will vary with the particular
condition or conditions being treated, the severity of the
condition, the duration of the treatment, and the specific
components of the composition being used.
[0163] The terms "administering" and "administration" are used
herein to mean any method which in sound medical practice delivers
the pharmaceutical composition to a subject in such a manner as to
provide a therapeutic effect.
[0164] The term "prodrug" is used herein to mean a compound which
releases an active agent in vivo when the prodrug is administered
to a subject. Prodrugs of an active agent are prepared by modifying
one or more functional groups present in the active agent in such a
way that the modification may be cleaved in vivo to release the
active compound.
[0165] The terms "treatment" or "treating" of a skin disorder
encompasses alleviation of at least one symptom thereof, a
reduction in the severity thereof, or the delay, prevention or
inhibition of the progression thereof. Treatment need not mean that
the disorder is totally cured. A useful composition herein need
only to reduce the severity of the disorder, reduce the severity of
symptoms associated therewith, provide improvement to a patient's
quality of life, or delay, prevent or inhibit the onset of the
disorder.
[0166] The term "pharmaceutically acceptable salt" refers to salts
that are pharmaceutically acceptable and that possess the desired
pharmacological activity of the parent compound.
[0167] Such salts include: (1) acid addition salts, formed with
acids such as, for example, acetic acid, benzoic acid, citric acid,
gluconic acid, glutamic acid, glutaric acid, glycolic acid,
hydrochloric acid, lactic acid, maleic acid, malic acid, malonic
acid, mandelic acid, phosphoric acid, propionic acid, sorbic acid,
succinic acid, sulfuric acid, tartaric acid, naturally and
synthetically derived amino acids, and mixtures thereof; or (2)
salts formed when an acidic proton present in the parent compound
is either (i) replaced by a metal ion e.g. an alkali metal ion, an
alkaline earth metal ion or an aluminum ion; or (ii) protonates an
organic base such as, for example, ethanolamine, diethanolamine,
triethanolamine, tromethamine and N-methylglucamine
[0168] Any concentration range, percentage range or ratio range
recited herein is to be understood to include concentrations,
percentages or ratios of any integer within that range and
fractions thereof, such as one tenth and one hundredth of an
integer, unless otherwise indicated.
[0169] It should be understood that the terms "a" and "an" as used
herein refer to "one or more" of the enumerated components. It will
be clear to one of ordinary skill in the art that the use of the
singular includes the plural unless specifically stated otherwise.
Therefore, the terms "a," "an" and "at least one" are used
interchangeably in this application.
[0170] Throughout the application, descriptions of various
embodiments use "comprising" language, however in some specific
instances, an embodiment can alternatively be described using the
language "consisting essentially of" or "consisting of".
[0171] All numbers expressing quantities, percentages or
proportions, and other numerical values used in the specification
and claims, are to be understood as being modified in all instances
by the term "about."
[0172] As used herein, the term "optionally" means that the
subsequently described event(s) may or may not occur, and includes
both event(s) which occur and events that do not occur.
[0173] As used herein, the term "substituted" refers to
substitution with the named substituent or substituents, multiple
degrees of substitution being allowed unless otherwise stated.
[0174] With regard to stereoisomers, the compounds of the Formulas
(I) and (II) herein may have one or more asymmetric carbon atom and
may occur as racemates, racemic mixtures and as individual
enantiomers or diastereomers. All such isomeric forms are included
within the present invention, including mixtures thereof.
[0175] C is (E) and trans (Z) isomerism may also occur. The present
invention includes the individual stereoisomers of the compounds of
the invention and where appropriate, the individual tautomeric
forms thereof, together with mixtures thereof.
[0176] Separation of diastereoisomers or cis and trans isomers may
be achieved by conventional techniques, e.g. by fractional
crystallization, chromatography or HPLC. A stereoisomeric mixture
of the agent may also be prepared from a corresponding optically
pure intermediate or by resolution, such as HPLC of the
corresponding racemate using a suitable chiral support or by
fractional crystallization of the diastereoisomeric salts formed by
reaction of the corresponding racemate with a suitable optically
active acid or base, as appropriate.
[0177] Other terms used herein are intended to be defined by their
well known meanings in the art.
EXAMPLES
Example 1
Degradation of Tazarotene in the Presence of Benzoyl Peroxide
[0178] DUAC.RTM. gel (1% clindamycin and 5% benzoyl peroxide
marketed by Stiefel Laboratories, Inc.) and TAZORAC.RTM. cream
(0.1% tazarotene marketed by Allergan, Inc.) have been successfully
used to treat facial acne. However, these topical treatments are
not approved for concomitant use. To study whether tazarotene is
susceptible to oxidative decomposition by benzoyl peroxide, an in
vitro laboratory study was conducted wherein a mixture of DUAC gel
and TAZORAC cream was prepared.
[0179] Samples were prepared by taking equal portions of DUAC gel
and TAZORAC cream and mixing them thoroughly at room temperature
with a spatula in a suitable container to form a uniform mixture.
The initial samples were analyzed immediately by HPLC. The other
samples were placed into an oven at 35.degree. C. and removed for
analysis after one, two, four, six and eight hours. An allowance
was made for product evaporation over the course of the study.
[0180] FIG. 1 and Table 1 illustrate that approximately 22% of
tazarotene was lost after four hours. The major degradant product
was tazarotene sulfoxide (.about.16% after 4 hours). A previously
unknown derivative was also identified, namely tazarotene benzoate,
which eluted chromatographically after tazarotene and accounted for
.about.6.3% by weight after four hours.
[0181] Similar results were obtained when "aged" samples of DUAC
gel and TAZORAC cream were used (Table 2). It is believed that the
tazarotene sulfoxide and tazarotene benzoate are oxidative reaction
products arising from reaction of the benzoyl peroxide in DUAC gel
with the tazarotene in TAZORAC cream.
TABLE-US-00001 TABLE 1 HPLC analysis of mixtures of DUAC gel and
TAZORAC cream (using "fresh" samples) Time % Label Point Tazarotene
Tazarotene Substance (hours) Preparation Tazarotene Sulfoxide
Benzoate RRT = 1.05 RRT = 1.15 TAZORAC 0 A 99.0 0.1 0.9 B 99.0 0.1
0.9 C 98.3 0.1 1.6 8 A 99.7 0.1 0.3 B 99.5 0.1 0.4 C 99.0 0.1 0.9
Mixtare 0 A 98.6 1.1 0.3 (DUAC/ B 98.6 1.1 0.3 TAZORAC) C 98.4 1.3
0.3 1 A 93.8 4.5 1.7 B 94.5 4.0 1.5 C 94.1 4.3 1.6 2 A 86.0 10.0
3.7 0.3 B 86.9 9.1 3.6 0.3 C 87.5 8.8 3.4 0.3 4 A 77.3 16.0 6.3 0.4
B 77.3 16.0 6.3 0.4 C 76.9 16.2 6.5 0.4 6 A 67.1 23.3 9.1 0.6 B
69.6 21.6 8.3 0.5 C 70.6 20.9 8.0 0.5 8 A 61.1 27.8 10.5 0.6 B 60.2
28.6 10.6 0.6 C 59.4 29.4 10.6 0.6
TABLE-US-00002 TABLE 2 HPLC analysis of mixtures of DUAC gel and
TAZORAC cream (using "aged" samples) % Label Time Tazarotene
Tazarotene Substance Point Preparation Tazarotene Sulfoxide
Benzoate RRT = 1.05 RRT = 1.15 TAZORAC 0 A 99.4 0.1 0.5 B 99.1 0.1
0.8 C 99.1 0.1 0.8 8 A 99.4 0.1 0.5 B 99.5 0.1 0.4 C 99.5 0.1 0.4
Mixture 0 A 99.2 0.8 (DUAC/ B 99.3 0.7 TAZORAC) C 99.2 0.8 1 A 95.2
3.5 1.3 B 95.2 3.4 1.4 C 95.3 3.5 1.3 2 A 89.1 7.8 3.1 B 89.0 7.7
3.0 0.3 C 89.1 7.6 3.0 0.3 4 A 76.9 16.3 6.5 0.4 B 77.0 16.2 6.5
0.4 C 77.1 16.0 6.5 0.4 6 A 63.4 25.6 10.5 0.5 B 63.7 25.5 10.3 0.5
C 64.2 25.2 10.1 0.6 8 A 54.6 31.9 12.9 0.6 B 54.2 32.2 12.9 0.7 C
53.6 32.7 13.1 0.7
Example 2
Further Study of Tazarotene and its Metabolites
[0182] An in vitro study was conducted to assess the formation of
tazarotene degradants following the application of a mixture of
DUAC gel and TAZORAC cream to human skin.
[0183] Equal portions of DUAC gel and TAZORAC cream were dispensed
into a glass vial and mixed for approximately three minutes with a
metal spatula to ensure a homogenous mixture. Samples of European
DUAC gel and US DUAC gel were used in separate experiments. The
products differ inasmuch as European DUAC gel does not contain
paraben preservatives. The test mixtures were then applied to the
surface of split-thickness skin (.about.0.25 mm) at a dose of 15.6
mg/cm.sup.2 and spread evenly using a positive displacement
pipette.
[0184] After 2 and 6 hours, the skin samples were washed, tape
stripped twice, and then the epidermis was peeled from the dermis
using a heat block. The skin samples were then extracted with
acetonitrile overnight at 4.degree. C. The distribution of
tazarotene and its degradants within the epidermis, dermis and
surface wash were quantified by LC/MS/MS with a 50 pg/mL LOQ. The
experiments were performed under yellow light conditions. For the
purposes of comparison, mixtures of DUAC gel and TAZORAC cream were
also prepared and retained for stability testing at 0, 2 and 6 hour
time points.
[0185] As illustrated in FIG. 2A, the mixture of DUAC gel and
TAZORAC cream in the stability samples resulted in the formation of
tazarotene sulfoxide. The quantity of the tazarotene sulfoxide
degradant doubled from the 2 hour time point to the 6 hour time
point. As shown in FIG. 2B, tazarotene benzoate also formed. Again,
there was a significant increase in the quantity of tazarotene
benzoate present at the 6 hour time point relative to the 2 hour
time point.
[0186] The study also showed that after 2 hours of application of
the DUAC/TAZORAC mixture to the skin, tazarotene sulfoxide was
identified in the epidermis and dermis (FIGS. 3A and 3B). After 6
hours of application, there was a continued loss of tazarotene and
resultant formation of tazarotene sulfoxide (FIGS. 4A and 4B).
[0187] Tazarotene benzoate was detectable in all samples including
the placebo (FIGS. 5A and 5B). The presence of tazarotene benzoate
in the placebo sample suggests that endogenous benzoic acid may be
present.
[0188] While tazarotene and tazarotene benzoate could not be
detected in the receiving medium of the assay (i.e. did not pass
through the skin), tazarotene sulfoxide was detected in the
receiving medium, as shown in FIG. 6.
[0189] Tazarotenic acid was not detected under these experimental
conditions.
Example 3
Retinoid Activity of Tazarotene, Tazarotene Benzoate and Tazarotene
Metabolites
[0190] A study was conducted to evaluate the retinoid activity of
tazarotene, tazarotene benzoate and tazarotene metabolites
(tazarotenic acid, tazarotene sulfone, tazarotenic acid sulfone and
tazarotenic acid sulfoxide).
[0191] SkinEthic RHE cultures were transferred into 6-well plates
containing 1.0 mL/well growth media. The cultures were equilibrated
at 37.degree. C. and the media was changed daily. The cultures were
subsequently placed in 60 mm petri dishes containing 3.5 mL growth
media. 6 .mu.l aliquots of the Test Articles shown in Table 3 were
applied to duplicate cultures. The cultures were incubated at
37.degree. C. for 72 hours. At the end of the incubation period,
the growth media was collected and stored at -20.degree. C. The
tissues were cut in half and one half was placed in 10% NBF for
histology, while the other half was placed in RNAlater.TM. solution
(Ambion). The following analyses were performed: a) IL-1.alpha. and
IL-8 activity assay; b) Hand E staining; c) Immunohistochemistry
for K10, K19 and filaggrin; and d) qRT-PCR to quantitate K10, K19
and filaggrin expression.
TABLE-US-00003 TABLE 3 Test Articles 1 Untreated (negative control)
2 Octyldodecanol (OD) vehicle control 3 TAZORAC .RTM. 0.1% cream 4
Retin-A Micro .RTM. 0.04% (tretinoin) gel 5 Tretinoin (0.1% in OD)
6 Tazarotene (0.1% in OD) 7 Tazarotenic acid (0.1% in OD) 8
Tazarotene benzoate (0.1% in OD) 9 Tazarotene sulfone (0.1% in OD)
10 Tazarotenic acid sulfoxide (0.1% in OD) 11 Tazarotenic acid
sulfone (0.1% in OD)
[0192] The study demonstrated that interleukin-1.alpha.
(IL-1.alpha.) (a pro-inflammatory cytokine) activity was only
slightly increased in cultures treated with tazarotene, tazarotene
benzoate or tazarotene metabolites compared to untreated and
vehicle controls (FIGS. 7 and 15). However, IL-1.alpha. activity
was significantly increased in cultures treated with TAZORAC cream,
and to a lesser extent with Retin-A Micro.RTM. tretinoin gel,
suggesting that formulation excipients may contribute to the
irritation potential of retinoids. Furthermore, interleukin-8
(IL-8) (a pro-inflammatory cytokine specific to retinoids) was
significantly increased in all cultures treated with retinoids
compared to untreated and vehicle treated controls, suggesting that
tazarotene, tazarotene benzoate and the tazarotene metabolites have
retinoid activity (FIGS. 7 and 16).
[0193] The histological profiles of cultures treated with TAZORAC
cream or Retin-A Micro gel were as expected: namely, there was a
decrease in keratohyalin granules (HandE), a decrease in K10
expression in the suprabasal layers, and an increase in K19
expression in all viable cell layers, compared to untreated
controls. Histological profiles for cultures treated with
tazarotene, tazarotene benzoate and the tazarotene metabolites were
similar to those of TAZORAC cream and Retin-A Micro gel, providing
further evidence that they have retinoid activity.
[0194] Following the histological profile study, gene expression
profiles for K10, K19 and filaggrin in RHE cultures treated with
the various retinoids were examined Gene expression profiles were
consistent with histological observations. There was a 3- to
1000-fold down regulation of K10 in all retinoid-treated cultures
compared to untreated and vehicle controls, with the possible
exception of tazarotene benzoate, which was uninterpretable due to
a high standard deviation. In addition, there was a 15- to
1500-fold up regulation of K19 in all retinoid-treated cultures
compared to untreated and vehicle controls. There was also a 2- to
15-fold down regulation of filaggrin in all retinoid-treated
cultures compared to untreated and vehicle controls. The filaggrin
expression after treatment with tazarotene benzoate appeared
equivocal due to a high variability in one culture. However, the
immunohistochemistry illustrates that filaggrin is down regulated
by tazarotene benzoate.
[0195] The results of these studies provide strong evidence that
tazarotene, tazarotene benzoate and the tazarotene metabolites have
retinoid activity in human skin.
Example 4
Retinoid Activity of Tazarotene Benzoate
[0196] A study was conducted to specifically evaluate the retinoid
activity of tazarotene benzoate, using a human keratinocyte model
(A431).
[0197] A431 cells were purchased from ATCC(CRL-1555). Cells were
seeded onto 12-well plates at a density of 250,000 cells/well and
incubated for 72 hours at 37.degree. C./5% CO.sub.2 to allow cells
to grow to confluency. Phorbol-12-myristate 13-acetate (PMA),
diluted in DMSO (10 mg/mL stock), was added in a concentration of
10 ng/mL and retinoids were added in concentrations of 0.01 to 1
.mu.g/mL from a 10 mg/mL stock solution in DMSO. Cultures were
incubated for 48 hours at 37.degree. C. At the end of the
incubation period, growth media was collected and cell viability
was determined using a CellTiterGlo assay kit (Promega).
Concentrations of IL-6 were determined by ELISA and normalized
based on cell viability.
[0198] It is known that PMA up regulates IL-6 expression through
transactivation of the nuclear transcription factor, AP-1.
Retinoids, such as tretinoin, are known to inhibit transactivation
of AP-1 via retinoic acid receptors.
[0199] The study illustrated that PMA-induced IL-6 release was
significantly decreased in cultures treated with tazarotene
benzoate, and was similar to the results obtained for cultures
treated with tretinoin, tazarotene and tazarotenic acid (FIG.
8).
[0200] As such, these results provide further evidence that
tazarotene benzoate has retinoid activity in human skin.
Example 5
Stability of Tazarotene Benzoate in Plasma
[0201] To further characterize tazarotene benzoate, the stability
of tazarotene benzoate, tazarotene sulfoxide and tazarotene in
human and rat plasma was studied.
[0202] Tazarotene, tazarotene sulfoxide and tazarotene benzoate
were incubated at room temperature with human and rat plasma. The
incubation was carried out in duplicate and samples were taken at
specific time points for stability analyses (i) rat samples (0
hour, 2 hours and 4 hours) and (ii) human samples (0 hour, 2 hours,
4 hours and 8 hours). Samples were analyzed by LC-MS/MS.
[0203] The study demonstrates that in rat plasma, tazarotene,
tazarotene sulfoxide and tazarotene benzoate showed rapid
degradation, with 75-100% loss in 2 hours (Table 4 and FIG. 9). In
human plasma, the rate of degradation of tazarotene, tazarotene
sulfoxide and tazarotene benzoate was significantly slower, with
<10% loss at 2 hours and <15% loss by 8 hours (Table 5 and
FIG. 10). The degradation products were the corresponding ester
hydrolysis products of each compound tested.
TABLE-US-00004 TABLE 4 Rat plasma 0 hour 2 hours 4 hours Tazarotene
(ng/mL) 16.4 <LOD <LOD Tazarotene sulfoxide (ng/mL) 34.1
<LOD <LOD Tazarotene benzoate (ng/mL) 59.8 15.0 2.29
TABLE-US-00005 TABLE 5 Human plasma 0 hour 2 hours 4 hours 8 hours
Tazarotene (ng/mL) 17.1 17.1 16.6 17.5 Tazarotene sulfoxide (ng/mL)
36.2 34.0 32.2 31.9 Tazarotene benzoate (ng/mL) 52.0 52.0 50.0
45.8
Example 6
Metabolism of Tazarotene, Tazarotene Sulfoxide, Tazarotenic Acid
and Tazarotene Benzoate in the Presence of Human Liver
Microsomes
[0204] The metabolic stability of tazarotene, tazarotene sulfoxide,
tazarotenic acid and tazarotene benzoate in the presence of human
liver microsomes was studied.
[0205] Hepatic microsomal reactions were carried out in
microcentrifuge tubes in the following manner. Human liver
microsomes (0.5 or 1.0 mg/ml protein), Test Article (1 or 10
.mu.M), paraoxon (0, 10 or 100 .mu.M), NADPH regenerating system
(10 mM glucose-6-phosphate, 1 unit/ml glucose-6-phosphate
dehydrogenase, 1 mM NADP.sup.+), magnesium chloride (5 mM) in 0.1 M
potassium phosphate buffer, pH 7.4 were incubated at 37.degree. C.
in a shaking water bath. Reactions were initiated with the addition
of substrate with the exception of the zero-time incubations. The
total reaction volume was 0.2 ml. The reactions were incubated for
15, 30, 45 or 60 minutes, terminated with 0.2 ml ice-cold
acetonitrile and then placed on ice. For zero-time incubations, ice
cold acetonitrile was added to the mixture containing microsomes,
along with NADPH regenerating system, magnesium chloride in
phosphate buffer and the Test Article. Each time point was carried
out in triplicate.
[0206] Disappearance of Test Article and formation of metabolites
following in vitro metabolism were determined by LC-MS/MS using
multiple reaction monitoring. LightSight.RTM. software (Applied
Biosystems, Foster City, Calif.) was used to generate the mass
spectrometry methods and carry out the data mining.
[0207] Control incubations were carried out with the identical
incubation procedures as described above with the following
exceptions. In negative control reactions, microsomes were not
included. Positive control incubations for liver microsomes
included an assessment of the microsomal stability of
7-ethoxycoumarin, which is quickly metabolized by CYPs in liver
microsomal incubations of laboratory animals and humans. Duplicate
reactions with an initial concentration of 10 .mu.M were incubated
for 0 or 30 minutes. Microsomal metabolic stability of
7-ethoxycoumarin was determined by LC-MS/MS.
TABLE-US-00006 TABLE 6 Metabolism of tazarotene, tazarotene
sulfoxide, tazarotenic acid and tazarotene benzoate Enzyme Conc k
R- Half-life Compound System (.mu.m) Type of reaction constant
squared (min) CL * Tazarotene HLM 1 Complete -0.0880 0.977 7.88 176
Without NADPH -0.0899 0.981 7.71 180 10 Complete -0.0827 0.988 8.38
165 Without NADPH -0.0914 0.988 7.58 183 Tazarotene HLM 1 Complete
-0.0689 0.963 10.1 138 sulfoxide Without NADPH -0.0779 0.994 8.90
156 10 Complete -0.0647 0.977 10.7 129 Without NADPH -0.0763 0.995
9.08 153 Tazarotenic HLM 1 Complete -0.0064 0.980 108 6.40 acid
Without NADPH 0.0003 0.124 0.00 0.00 10 Complete -0.0047 0.596 147
4.70 Without NADPH 0.0006 0.037 0.00 0.00 Tazarotene HLM 1 Complete
-0.0893 0.967 7.76 179 benzoate Without NADPH -0.0964 0.954 7.19
193 10 Complete -0.0097 0.897 71.4 9.70 Without NADPH -0.0146 0.980
47.5 14.6 Tazarotene HSkM 1 Complete -0.0014 0.656 495 0.700
benzoate Without NADPH -0.0032 0.360 217 1.60 10 Complete -0.0017
0.283 408 0.850 without NADPH -0.0015 -0.194 462 0.800 *= ml/min/mg
indicates data missing or illegible when filed
[0208] 15.4% to 19.8% of tazarotene was converted to tazarotenic
acid in complete non-zero minute incubations (with NADPH) (Table
7). In the absence of NADPH, incubations contained higher
concentrations of tazarotenic acid (32.4% to 52.7% of tazarotene
converted). Tazarotenic acid makes up only a fraction of the
metabolism, suggesting the existence of other metabolic pathways
such as sulfoxidation to tazarotene sulfoxide or additional
metabolism of tazarotenic acid to tazarotenic acid sulfoxide and
tazarotenic acid sulfone.
TABLE-US-00007 TABLE 7 Metabolism of tazarotene to tazarotenic acid
Percent of initial tazarotene concentration 1 .mu.M initial
concentration 10 .mu.M initial concentration Type of Incubation
Tazarotenic Tazarotenic Reaction time (min) Tazarotene acid Total
Tazarotene acid Total Complete 0 100% 0.00% 100% 100% 0.00% 100%
(with 15 21.1% 18.0% 39.1% 24.1% 15.4% 39.5% NADPH) 30 4.91% 19.6%
24.5% 6.55% 18.4% 24.9% 45 1.80% 19.6% 21.4% 2.18% 18.3% 20.4% 60
0.70% 19.8% 20.5% 0.89% 17.4% 18.3% Without 0 100% 0.00% 100% 100%
0.00% 100% NADPH 15 22.0% 37.2% 59.2% 21.9% 32.4% 54.3% 30 4.86%
44.7% 49.6% 4.64% 39.5% 44.1% 45 1.43% 48.5% 49.9% 1.48% 41.3%
42.8% 60 0.65% 52.7% 53.4% 0.55% 40.5% 41.1%
[0209] Tazarotene sulfoxide was also rapidly metabolized in human
liver microsomes (Table 8). Near-quantitative conversion to the
tazarotenic acid sulfoxide was observed for 1 .mu.M reactions as
shown in the mass balance calculations. In the case of 1 .mu.M
reactions without NADPH, the percentage values of tazarotene
sulfoxide converted to tazarotenic acid sulfoxide were over 100%.
This is an unexpected result which may be due to ion suppression
effects between standard and sample injections. For 10 .mu.M
substrate reactions, greater than 50% of the Test Article
metabolized to tazarotenic acid sulfoxide. In the presence of
NADPH, tazarotenic acid sulfoxide was a major metabolite, but its
levels were lower than those observed in incubations without NADPH.
Only a fraction of NADPH-dependent metabolism is detected as
tazarotenic acid sulfoxide. This suggests other metabolic pathways
either by oxidation of tazarotene sulfoxide to its sulfone or by
additional metabolism of tazarotenic acid sulfoxide to its
sulfone.
TABLE-US-00008 TABLE 8 Metabolism of tazarotene sulfoxide to
tazarotenic acid sulfoxide Percent of initial tazarotene sulfoxide
concentration 1 .mu.M initial concentration 10 .mu.M initial
concentration Tazarotenic Tazarotenic Type of Incubation Tazarotene
acid Tazarotene acid Reaction time (min) sulfoxide sulfoxide Total
sulfoxide sulfoxide Total Complete 0 100% 0.00% 100% 100% 0.00%
100% (with 15 25.6% 43.1% 68.7% 30.9% 27.7% 58.6% NADPH) 30 8.86%
50.8% 59.7% 11.4% 38.3% 49.7% 45 4.24% 55.4% 59.7% 4.80% 38.4%
43.2% 60 2.17% 56.7% 58.9% 2.70% 41.0% 43.7% Without 0 100% 0.00%
100% 100% 0.00% 100% NADPH 15 27.9% 87.1% 115% 30.4% 58.4% 88.8% 30
8.40% 108% 116% 8.96% 74.2% 83.2% 45 2.72% 112% 115% 2.98% 76.6%
79.6% 60 1.11% 116% 117% 1.18% 79.1% 80.3%
[0210] In the presence of NADPH, tazarotenic acid was slowly
metabolized by human liver microsomes to tazarotenic acid sulfoxide
(Table 9). Tazarotenic acid was not metabolized in the absence of
NADPH. A mass spectrum for tazarotenic acid sulfoxide is shown in
FIG. 14.
TABLE-US-00009 TABLE 9 Metabolism of tazarotenic acid to
tazarotenic acid sulfoxide Percent of initial tazarotenic acid
concentration 1 .mu.M initial concentration 10 .mu.M initial
concentration tazarotenic tazarotenic Type of Incubation
tazarotenic acid tazarotenic acid Reaction time (min) acid
sulfoxide Total acid sulfoxide Total Complete 0 100% 0.00% 100%
100% 0.00% 100% (with 15 89.9% 12.6% 103% 93.1% 3.83% 96.9% NADPH)
30 82.0% 22.3% 104% 88.6% 7.68% 96.3% 45 75.8% 30.4% 106% 77.8%
10.3% 88.1% 60 68.0% 35.9% 104% 77.4% 13.6% 91.0% Without 0 100%
0.00% 100% 100% 0.00% 100% NADPH 15 100% 0.00% 100% 102% 0.01% 102%
30 101% 0.00% 101% 99.0% 0.01% 99.0% 45 102% 0.00% 102% 106% 0.01%
106% 60 101% 0.00% 101% 102% 0.02% 102%
[0211] 31.7% to 47.6% of tazarotene benzoate was converted to
hydroxy tazarotenic acid in 1 .mu.M reactions with NADPH.
Similarly, greater than 50% of tazarotene benzoate was converted to
hydroxy tazarotenic acid in 1 .mu.M reactions without NADPH (Table
10). Since the mass balance is significantly less than 100%,
particularly for the 1 .mu.M reactions, it appears that other
metabolites are also formed. A HPLC chromatogram and mass spectrum
corresponding to hydroxy tazarotenic acid is shown in FIGS. 12 and
13, respectively.
TABLE-US-00010 TABLE 10 Metabolism of tazarotene benzoate to
hydroxy tazarotenic acid Percent of initial tazarotene benzoate
concentration 1 .mu.M initial concentration 10 .mu.M initial
concentration hydroxy hydroxy Type of Incubation tazarotene
tazarotenic tazarotene tazarotenic Reaction time (min) benzoate
acid Total benzoate acid Total Complete 0 100% 0.00% 100% 100%
0.00% 100% (with 15 20.3% 31.7% 52.0% 99.3% 6.10% 105% NADPH) 30
4.45% 47.6% 52.1% 73.4% 15.6% 89.0% 45 1.47% 43.8% 45.3% 63.2%
24.3% 87.5% 60 0.73% 35.2% 35.9% 55.2% 29.2% 84.4% Without 0 100%
0.00% 100% 100% 0.00% 100% NADPH 15 17.3% 54.5% 71.8% 87.0% 13.2%
100% 30 2.97% 71.1% 74.1% 64.0% 32.4% 96.4% 45 1.07% 63.1% 64.2%
51.0% 43.2% 94.2% 60 0.53% 53.1% 53.6% 41.0% 51.5% 92.5%
[0212] The study demonstrated that tazarotene, tazarotene
sulfoxide, tazarotenic acid and tazarotene benzoate were
metabolized by human liver microsomes. Ester hydrolysis is believed
to be a major metabolic pathway.
[0213] To determine the role of esterases in metabolism of
tazarotene, tazarotene sulfoxide, tazarotenic acid and tazarotene
benzoate, inhibition studies were carried out with paraoxon, a
potent inhibitor of all serine esterases including
carboxylesterases. Paraoxon inhibited: [0214] (i) tazarotene
metabolism to tazarotenic acid in human liver microsomes, [0215]
(ii) tazarotene sulfoxide metabolism to tazarotenic acid sulfoxide
in human liver microsomes, and [0216] (ii) tazarotene benzoate
metabolism to hydroxy tazarotenic acid in human liver and skin
microsomes. Paraoxon did not inhibit the metabolism of tazarotenic
acid to tazarotenic acid sulfoxide, which is a CYP- and
FMO-mediated reaction.
[0217] In all, these results support a conclusion that esterases
are responsible for ester hydrolysis of tazarotene, tazarotene
sulfoxide and tazarotene benzoate.
[0218] Human liver microsomes metabolized 7-ethoxycoumarin as
expected, confirming satisfactory incubation conditions for the
metabolic stability assay.
[0219] Among the metabolites detected, three were identified as
tazarotenic acid benzoate (m/z 444), hydroxy tazarotene (m/z 368),
and hydroxy tazarotenic acid (m/z 340). Hydroxy tazarotenic acid
was identified as a major metabolite. Metabolites with m/z 338 and
366 were also observed. While not bound by the proposal, it is
believed that these are products following enzymatic oxidation of
the thiolactol group to the thiolactone i.e. to form keto
tazarotene and keto tazarotenic acid (FIG. 23). In all, these
findings are consistent with cleavage of both ester bonds by
esterases.
[0220] The proposed metabolism of (i) tazarotene and (ii)
tazarotene benzoate is illustrated in FIGS. 22 and 23,
respectively.
Example 7
Metabolism of Tazarotene Benzoate in the Presence of Human Skin
Microsomes
[0221] Insofar as several liver microsomal enzymes (including
esterases) are found in the human skin, the metabolism of
tazarotene benzoate was further studied in vitro in the presence of
human skin microsomes.
[0222] Five time points were chosen, but because of the limitation
of human skin microsome supply, each one was carried out in
duplicate. Skin microsomal reactions were carried out as described
above for hepatic microsomal reactions with the following two
exceptions. Firstly, the total reaction volume was 0.1 mL.
Secondly, incubations were terminated with 0.1 mL acetonitrile.
[0223] Human skin microsomes catalyzed fexofenadine formation from
terfenadine (positive control), confirming drug metabolizing
activity of human skin microsomes.
[0224] The tazarotene benzoate and hydroxy tazarotenic acid
metabolite concentrations were quantified by LC-MS/MS.
[0225] The results showed that while tazarotene benzoate was
metabolized by the human skin microsomes, the compound was
metabolized at a slower rate relative to human liver microsomes
i.e. after 150 min, 20% of tazarotenic benzoate was metabolized in
the presence of 2 mg/ml human skin microsomes. Formation of hydroxy
tazarotenic acid was again observed, suggesting esterase metabolism
of tazarotene benzoate.
Example 8
[0226] The retinoid activity of tazarotene, tazarotene benzoate,
hydroxy tazarotenic acid, keto tazarotenic acid, keto tazarotene
and a number of analogues of tazarotene benzoate were evaluated
using the following methodology. The compounds are set out in Table
11.
[0227] Reconstructed human epidermis (RHE) tissues were cultured
in-house as previously described by Poumay et al. Briefly,
polycarbonate culture inserts (12 mm diameter and 0.4 .mu.m pore
size, Millipore) were filled with 150 .mu.L of a suspension
containing approximately 5.times.10.sup.5 primary adult human
keratinocytes. The inserts received another 500 .mu.L of
keratinocyte culture media and were placed in a 6-well plate (1
insert/well) containing 2.5 mL of RHE Growth Media (Epilife
media+1.5 mM CaCl.sub.2). RHE cultures were incubated at 37.degree.
C. in a humidified atmosphere containing 5% CO.sub.2, for 24 hours.
Subsequently (on Day 0), RHE cultures were exposed to the
air-liquid interface by removing the RHE Growth Media from the top
of the cultures, and replacing with 1.5 mL/well of RHE Growth Media
containing 50 .mu.g/mL vitamin C. Media was changed every other day
until the cultures were dosed with Test Articles. A stock solution
of 0.1% tazarotene (2.83 mM at 99.5% purity) in OD/10% DMSO was
prepared. For tazarotene benzoate, hydroxytazarotenic acid, keto
tazarotenic acid, keto tazarotene, and tazarotene nicotinate, a 10
mg/mL stock solution (in DMSO) was already prepared. From this
stock solution, a 2.83 mM working solution (in octyldodecanol) was
prepared. All other tested compounds were resuspended in DMSO and
OD to obtain a final concentration of 2.83 mM in OD/10% DMSO. On
Day 12, the cultures were placed in 60 mm petri dishes containing 3
mL of RHE Growth Media (+VitC). Test articles (6 .mu.l) were
applied to triplicate cultures and cultures were incubated at
37.degree. C. for 72 hours. Untreated and OD alone served as
negative controls. At the end of the incubation period, the growth
media was collected and stored at -20.degree. C. The tissues were
cut in half: one half was placed in 10% NBF for histology, and the
other half was placed in RNAlater.TM. solution for RT-qPCR. RNA was
isolated and concentrations were determined using a NanoDrop
spectrophotometer. In addition to using the same amount of RNA for
each sample, data was normalized to internal GAPDH mRNA levels and
is expressed as relative quantification (RQ) to untreated controls.
RNA extracts from each replicate were amplified using RT-qPCR. The
relative gene expression of five biomarkers was determined: Keratin
10, Keratin 19, Filaggrin, Keratin 4, and Keratin 13.
[0228] The results of the analyses are shown in FIGS. 17 to 21. The
compounds displayed on the X axes of FIGS. 17 to 21 correspond to
the compounds set out in Table 11. The compounds were ranked for
their effect on each biomarker, as set out in Table 12.
[0229] Keratin 4 (K4) is not normally expressed in human epidermis
but is known to be upregulated upon treatment with retinoids. All
tazarotene derivatives caused significant upregulation of K4 (from
11-180-fold) compared to untreated and vehicle controls.
Tazarotene, keto tazarotene, compound 17, compound 25 and compound
28 showed the highest increase (from 103 to 180-fold). Compound 21
and compound 19 showed the lowest upregulation with 11 and 19-fold,
respectively.
[0230] Keratin 10 (K10) is an early differentiation marker that is
normally expressed in the suprabasal layers of the viable
epidermis, but is known to be downregulated upon treatment with
retinoids. With the exception of the S enantiomer of tazarotene
benzoate, compound 19 and compound 21, all other tazarotene
derivatives caused a significant downregulation of K10
(approximately 7.+-.4-fold) compared to untreated and vehicle
controls. The highest K10 downregulation was observed with
tazarotene nicotinate, keto tazarotenic acid, and compound 24 (14
to 17-fold).
[0231] Keratin 13 (K13) is not normally expressed in human
epidermis but is known to be upregulated upon treatment with
retinoids. With the exception of compound 19 and compound 21, all
tazarotene derivatives caused a significant upregulation of K13
(approximately 13.+-.5-fold) compared to untreated and vehicle
controls. The highest K13 upregulation was observed with compound
24 (23-fold), keto tazarotenic acid, and hydroxy tazarotene
(20-fold), compound 23 and compound 27 (19-fold), compound 28
(18-fold), and compound 25 (17-fold).
[0232] Keratin 19 (K19) is not normally expressed in human
epidermis but is known to be upregulated in all the viable layers
of the epidermis upon treatment with retinoids. With the exception
of compound 19 and compound 21, all other tazarotene derivatives
caused a significant upregulation of K19 (approximately
23.+-.11-fold) compared to untreated and vehicle controls.
Tazarotene, compound 15, compound 23, compound 24 and compound 27
showed the highest increase (33 to 43-fold).
[0233] Filaggrin is a late-stage differentiation marker that is
normally expressed in the stratum granulosum and is known to be
downregulated upon treatment with retinoids. With the exception of
the S enantiomer of tazarotene benzoate, keto tazarotene, compound
13, compound 17, compound 19, and compound 21, all other tazarotene
derivatives caused a significant (3-100-fold) downregulation of
filaggrin. The highest level of filaggrin downregulation was
observed with tazarotene nicotinate (100-fold), compound 24
(56-fold), keto tazarotenic acid (36-fold) and compound 27
(23-fold).
[0234] Based on a qualitative assessment of gene expression
profiles (Table 12), the top 5 tazarotene derivatives are: compound
24, compound 23, compound II, compound 29 and compound 15.
[0235] In summary, the retinoid activity of a variety of tazarotene
metabolites and derivatives were assessed by 5 biomarkers (Keratins
4, 10, 13, 19 and Filaggrin). The respective compounds had unique
expression profiles. In ranking the compounds tested, 13
derivatives were found to be more active than tazarotene.
Example 9
Stability of Tazarotene Benzoate and Tazarotene Nicotinate in the
Presence of Benzoyl Peroxide
[0236] The reaction of (i) tazarotene, tazarotene benzoate, hydroxy
tazarotenic acid and tazarotene nicotinate with (ii) benzoyl
peroxide (BPO) in 30% aqueous solutions was monitored at 35.degree.
C., room temperature and 5.degree. C.
[0237] Individual solutions of each compound were prepared at
approximately 0.25 mg/mL in acetonitrile:water (6:4 by volume).
Reactions were initiated by mixing equal volumes of the test
solution with an approximately 12 mg/mL solution of benzoyl
peroxide (BPO) in acetonitrile:water (4:1 by volume). Therefore,
the reaction solution contained approximately 0.125 mg/mL of the
test compound and the BPO was at a 50-fold excess by weight (i.e.
at the same ratio as a product containing 0.1% tazarotene and 5%
BPO). Aliquots of the reaction solutions were stored at various
temperatures protected from light.
[0238] Reactions were quenched by diluting 30 .mu.L of the reaction
solution to 50 mL with a diluent (acetonitrile:water in a ratio of
1:1 by volume) and storing the sample at 10.degree. C. in the LC/MS
sample tray or at 5.degree. C. for storage. Duplicate samples were
prepared at each time point (three at the start of the reaction)
and the results were averaged together to generate a single
value.
[0239] Samples were analyzed on a Waters Acquity UPLC with a Waters
Xevo TQMS using an ESI source in the positive mode controlled by
MassLynx V4.1 software. Separations were performed using an Acquity
BEH C8 UPLC column (1.7 .mu.m particle size, 2.1.times.50 mm) at
45.degree. C. The mobile phase consisted of water and acetonitrile,
each containing 0.1% formic acid. A flow rate of 0.4 mL/min was
used.
[0240] The results are set out in FIGS. 24A, 24B and 24C.
[0241] Significantly, at all three temperatures, tazarotene
benzoate and tazarotene nicotinate were in the order of 25 times
less reactive than tazarotene and hydroxy tazarotenic acid (with
BPO). The rate of reaction of each of the test compounds with BPO
was found to be a function of temperature. The rate of reaction
increased roughly by a factor of 5 at room temperature compared to
5.degree. C. and increased a further factor of approximately 3 when
the reaction temperature was increased to 35.degree. C. The
reaction rates of tazarotene benzoate and tazarotene nicotinate
appear to be similar at all temperatures.
Example 10
Synthesis of Tazarotene Derivatives
[0242] The invention will now be described by reference to the
following examples which are merely illustrative and are not to be
construed as a limitation of the scope of the present invention.
All temperatures are given in degrees centigrade, all solvents are
highest available purity and all reactions run under anhydrous
conditions in an Ar atmosphere where necessary.
TABLE-US-00011 List of Abbreviations DMAP: 4- SPE: Solid phase
extraction (Dimethylamino)pyridine DCM: Dichloromethane m-CPBA:
3-Chlorobenzene- carboperoxoic acid DMF: N,N-Dimethylformamide
Fmoc: Fluorenylmethyloxycarbonyl dppf: 1,1'-Bis(diphenylphosphino)-
NIS: N-Iodosuccinimide ferrocene DMSO: Dimethylsulfoxide HATU:
O-(7-Azabenzotriazol-1-yl)- N,N,N',N'-tetramethyluronium
hexafluorophosphate DIPEA: N,N- HBTU: O-Benzotriazol-1-yl-
Diisopropylethylamine N,N,N',N'-tetramethyluronium
hexafluorophosphate DSC: differential scanning HOBT:
1-Hydoxybenzotriazole calorimetry hydrate EtOAc: Ethyl acetate IPA:
isopropyl alcohol EDC: 1-(3-Dimethylaminopropyl)- THF:
Tetrahydrofuran 3-ethylcarbodiimide hydrochloride TFA:
Trifluoroacetic anhydride mol: moles TEA: Triethylamine VCD:
Vibrational Circular Dichroism analysis M: molar mmol: millimoles
L: liters satd: saturated mL: milliliters eq: equivalents g: grams
min: minutes mg: milligrams mp: melting point h: hours rt: room
temperature Aq: aqueous NMP = 1-methyl-2-pyrrolidinone
General Procedure for the Preparation of Acid Chlorides
[0243] Oxalyl chloride (4.0 equivalents) was added to a solution of
carboxylic acid (1.0 equivalent) in dichloromethane (DCM) while
stirring, along with a catalytic amount of anhydrous dimethyl
formamide (DMF). The resultant solution was refluxed at 40.degree.
C. for 2 hours. The solution was cooled, the solvent removed under
vacuum, the excess oxalyl chloride removed using toluene, and the
resultant acid chloride was redissolved in DCM and subsequently
used for ester formation.
General Procedure for the Preparation of Esters from Acid
Chlorides
[0244] The acid chloride (1.6 mmol) was added to a solution of
compound 14 (0.5 mmol) in DCM (5 mL) while stirring. Triethylamine
(TEA) (2.7 mmol) was subsequently added and the reaction mixture
was stirred overnight. The progress of the reaction was monitored
by LC/MS. Upon completion of reaction, the reaction mixture was
poured into water, extracted with DCM (2.times.5 mL aliquots). The
organic extracts were combined and washed with water/brine and
dried over anhydrous Na.sub.2SO.sub.4. The organic extract was
concentrated and the crude ester was purified with an ISCO
cartridge in a Companion system using an ethylacetate/heptanes
solvent system (0-40%).
General Procedure for the Preparation of Esters from the Coupling
of a Carboxylic Acid and an Alcohol (Using EDC and HOBt)
[0245] N-(3-Dimethylaminopropyl)-N'-ethylcarbodiimide hydrochloride
(EDC.HCl) (2.7 mmol) and HOBt (2.7 mmol) was added to a solution of
the carboxylic acid (2.7 mmol) in DCM (10 mL), while stirring. TEA
(5.4 mmol) was added, followed by compound 14 (an alcohol). The
reaction mixture was stirred overnight at room temperature. Upon
completion of the reaction (determined by LC/MS), the mixture was
poured into water (20 mL), the organic phase removed and the
aqueous phase extracted with DCM (10 mL). The organic (DCM) phase
was washed with brine and dried over anhydrous Na.sub.2SO.sub.4 to
give the crude ester.
[0246] The molecular weight of the metabolites and analogues as
determined by mass spectrometry is listed in Table 11.
[0247] Analysis of the metabolites and analogues was also conducted
using .sup.1H NMR spectroscopy at 400 MHz (Varian), with the
samples dissolved in deuterated chloroform or deuterated DMSO.
Compound
4--6-(2-(2-benzoyloxy-4,4-dimethylthiochroman-6-yl)ethynyl)nicoti-
nic acid, ethyl ester (tazarotene benzoate)
[0248] Triethylamine (0.75 mL) was added to a cooled (0.degree. C.)
solution of compound 14 (0.551 g, 1.5 mmol) in DCM (15 mL) under
nitrogen, followed by the addition of benzoyl chloride (0.281 g,
2.0 mmol) in DCM (3 mL). The mixture was stirred for 1 hour at room
temperature and then diluted with DCM (50 mL) and then treated with
saturated NaHCO.sub.3 solution, followed by water (30 mL) and brine
(30 mL). The organic phase was extracted, dried over anhydrous
Na.sub.2SO4, concentrated and purified using column chromatography
(20% EtOAc/Heptanes) to obtain a colorless solid. Yield: 0.700 g
(99%).
[0249] 1H NMR (400 MHz, CHLOROFORM-d) d 1.43 (t, J=7.08 Hz, 3H),
1.49 (s, 3H), 1.56 (s, 3H), 2.32 (br. s., 1H), 2.33 (d, J=1.66 Hz,
1H), 4.44 (q, J=7.13 Hz, 2H), 6.49 (t, J=5.52 Hz, 1H), 7.13 (d,
J=8.10 Hz, 1H), 7.35 (d, J=0.88 Hz, 1H), 7.46 (t, J=7.71 Hz, 2H),
7.59 (d, J=7.91 Hz, 2H), 7.69 (s, 1H), 8.05 (d, J=7.52 Hz, 2H),
8.29 (dd, J=8.15, 1.81 Hz, 1H), 9.21 (s, 1H)
Compounds 5 and
6--(S)-6-(2-(2-benzoyloxy-4,4-dimethylthiochroman-6-yl)ethynyl)nicotinic
acid, ethyl ester and
(R)-6-(2-(2-benzoyloxy-4,4-dimethylthiochroman-6-yl)ethynyl)nicotinic
acid, ethyl ester (enantiomers of tazarotene benzoate)
[0250] The S and R enantiomers of compound 4 (100 mg) were
separated by HPLC using a chiral ADH column with a 10-50% gradient
of isopropyl alcohol/water. UV absorbance was monitored at 340 nm.
33 mg and 27 mg of the respective enantiomers were obtained in
>97% purity.
[0251] The stereochemistry of the enantiomers was determined using
Ab Initio Vibrational Circular Dichroism (VCD) analysis.
Compound
7--6-[4,4-Dimethyl-2-(pyridine-3-carbonyloxy)thiochroman-6-ylethy-
nyl]nicotinic acid ethyl ester (tazarotene nicotinate)
[0252] A solution of compound 14 (1.00 g, 2.72 mmol) in DCM (100
mL) was chilled in an ice water bath to 0.degree. C., then charged
with TEA (1.38 g, 1.90 mL, 13.6 mmol), and then nicotinoyl chloride
hydrochloride (605 mg, 3.40 mmol) was added. The reaction was then
allowed to warm to room temperature and stirred for 18 hours. The
reaction was diluted with DCM (200 mL) and washed with water
(2.times.200 mL aliquots). The aqueous washes were then pooled and
back-extracted with DCM (2.times.100 mL). The organic fractions
were then pooled, dried over Na.sub.2SO.sub.4, filtered and
concentrated under reduced pressure. The crude product was
chromatographed on a silica column using a heptane:EtOAc solvent
system. Yield: 968 mg (75%).
[0253] .sup.1H NMR (400 MHz, CHLOROFORM-d) .delta. ppm 1.43 (t,
J=7.1 Hz, 3H), 1.49 (s, 3H), 1.56 (s, 3H), 2.33 (d, J=5.6 Hz, 2H),
4.44 (q, J=7.1 Hz, 2H), 6.51 (t, J=5.6 Hz, 1H), 7.13 (d, J=8.2 Hz,
1H), 7.37 (dd, J=8.1, 1.8 Hz, 1H), 7.41 (ddd, J=8.0, 4.9, 0.8 Hz,
1H), 7.59 (dd, J=8.2, 0.8 Hz, 1H), 7.69 (d, J=1.7 Hz, 1H),
8.22-8.36 (m, 2H) 8.81 (dd, J=4.9, 1.7 Hz, 1H), 9.22 (ddd, J=9.3,
2.1, 0.8 Hz, 2H).
Compounds 8 and
9--6-[4,4-Dimethyl-2-(pyridine-3-carbonyloxy)thiochroman-6-ylethynyl]nico-
tinic acid ethyl ester (tazarotene nicotinate --S and R
enantiomers)
[0254] The S and R enantiomers of compound 7 were separated by
supercritical fluid chromatography using an OJH column
(10.times.250 mm at 10 ml/min) using 15% ethanol as a modifier. UV
absorbance was monitored at 254 nm. The respective enantiomers were
obtained in a purity of about 96%.
[0255] The stereochemistry of the enantiomers was determined using
Ab Initio Vibrational Circular Dichroism (VCD) analysis.
Compound
10--6-((2-hydroxy-4,4-dimethylthiochroman-6-yl)ethynyl)nicotinic
acid (hydroxytazarotenic acid)
6-(4,4-Dimethyl-1-oxo-1.lamda..sup.4-thiochroman-6-ylethynyl)nicotinic
acid ethyl ester
[0256] A suspension of tazarotene (10.0 g, 28.5 mmol) in methanol
(300 mL) was chilled in an ice water bath to <10.degree. C., and
then charged with the dropwise addition of a solution of NaIO.sub.4
(9.13 g, 42.7 mmol) in water (100 mL) over 30 minutes. The reaction
was allowed to warm to room temperature while stirring for 18
hours, and was then concentrated under reduced pressure to remove
as much methanol as possible. The reaction was then diluted with
DCM (500 mL) and water (150 mL). The two layers were then
separated, and the aqueous layer was extracted with DCM
(2.times.100 mL aliquots). The organic fractions were pooled, dried
over Na.sub.2SO.sub.4, filtered, and concentrated under reduced
pressure. The crude sulfoxide product was then chromatographed
using a DCM:EtOAc solvent system. Yield: 9.00 g (86%).
[0257] .sup.1H NMR (400 MHz, CDCl.sub.3) .delta. ppm 1.34 (s, 3H),
1.43 (t, J=7.1 Hz, 3H), 1.47 (s, 3H), 1.91 (ddd, J=15.1, 8.9, 2.3
Hz, 1H), 2.45 (ddd, J=15.1, 10.3, 2.4 Hz, 1H), 3.04-3.29 (m, 2H),
4.44 (q, J=7.1 Hz, 2H), 7.58 (dd, J=8.1, 1.6 Hz, 1H), 7.63 (dd,
J=8.2, 0.7 Hz, 1H), 7.71 (d, J=1.6 Hz, 1H), 7.78 (d, J=8.1 Hz, 1H),
8.32 (dd, J=8.2, 2.2 Hz, 1H), 9.22 (dd, J=2.1, 0.7 Hz, 1H). MS
(ESI+) 368.0.
6-(2-Acetoxy-4,4-dimethylthiochroman-6-ylethynyl)nicotinic acid
ethyl ester
[0258] A solution of the above sulfoxide (9.00 g, 24.5 mmol) in
acetic anhydride (185 mL) was heated to 130.degree. C. for 5 hours,
then concentrated under reduced pressure, with toluene added to aid
evaporation of the acetic anhydride. The crude acetate was then
chromatographed on a silica plug using a heptane:EtOAc solvent
system. Yield: 8.47 g (84%).
[0259] .sup.1H NMR (400 MHz, CDCl.sub.3) .delta. ppm 1.40 (s, 3H),
1.43 (t, J=7.2 Hz, 3H), 1.46 (s, 3H), 2.10-2.22 (m, 2H), 2.11 (s,
3H), 4.43 (q, J=7.1 Hz, 2H), 6.22 (dd, J=6.9, 5.2 Hz, 1H), 7.11 (d,
J=8.1 Hz, 1H), 7.34 (dd, J=8.2, 1.8 Hz, 1H), 7.58 (dd, J=8.2, 0.8
Hz, 1H), 7.64 (d, J=1.7 Hz, 1H), 8.29 (dd, J=8.2, 2.2 Hz, 1H), 9.20
(dd, J=2.2, 0.8 Hz, 1H). MS (ESI+) 410.0.
6-((2-hydroxy-4,4-dimethylthiochroman-6-yl)ethynyl)nicotinic
acid
[0260] A suspension of the above acetate (3.00 g, 7.33 mmol) in
ethanol (90 mL) was charged with the dropwise addition of a
solution of KOH (2.47 g, 44.0 mmol) in water (15 mL). Within 30
minutes the reaction became homogenous, and was then allowed to
stir at room temperature for 18 hours. The reaction was then
concentrated under reduced pressure, diluted with water (40 mL),
and then treated with the dropwise addition of 1.0 N HCl (33 mL)
until a pH of -5 was reached. The resulting yellow precipitate was
filtered, and the filter cake was then washed with water (40 mL)
and heptane (40 mL), and then dried under vacuum at 50.degree. C.
for 18 hours. Yield: 1.95 g (78%).
[0261] .sup.1H NMR (400 MHz, DMSO-d.sub.6) .delta. ppm 1.24 (s,
3H), 1.42 (s, 3H), 1.90 (dd, J=13.5, 9.8 Hz, 1H), 2.11 (dd, J=13.5,
4.2 Hz, 1H), 5.43 (dd, J=9.8, 4.2 Hz, 1H), 7.11 (d, J=8.2 Hz, 1H),
7.32 (dd, J=8.1, 1.8 Hz, 1H), 7.62 (d, J=1.8 Hz, 1H), 7.72 (dd,
J=8.1, 0.7 Hz, 1H), 8.26 (dd, J=8.1, 2.2 Hz, 1H), 9.04 (dd, J=2.2,
0.8 Hz, 1H). MS (ESI+) 340.0.
Compound
11--6-((4,4-dimethyl-2-oxothiochroman-6-yl)ethynyl)nicotinic acid
(keto tazarotenic acid)
[0262] A suspension of compound 12 (1.28 g, 3.50 mmol) in ethanol
(30 mL) was charged with the dropwise addition of a solution of KOH
(2.47 g, 44.0 mmol) in water (15 mL), and the reaction was allowed
to stir at room temperature for 18 hours. The reaction was then
concentrated under reduced pressure, diluted with water (20 mL),
and then treated with the dropwise addition of 1.0 N HCl until a pH
of -5 was reached. The resulting yellow precipitate was filtered,
and the filter cake was then washed with water (10 mL) and heptane
(10 mL), and then dried under vacuum at 50.degree. C. for 18 hours.
Crude product (1.12 g) was then dissolved in DMSO and purified by
reversed-phase HPLC using a methanol:water gradient with 0.1%
HCO.sub.2H present in both solvents. Yield: 26 mg (2.2%).
[0263] .sup.1H NMR (400 MHz, DMSO-D.sub.6) .delta. ppm 1.35 (s,
6H), 2.80 (s, 2H), 7.37 (br. d, J=7.8 Hz, 1H), 7.52 (br. d, J=7.8
Hz, 1H), 7.65-7.80 (m, 2H), 8.23 (br. d, J=7.2 Hz, 1H), 9.01 (br.
s, 1H).
Compound 12--ethyl
6-((4,4-dimethyl-2-oxothiochroman-6-yl)ethynyl)nicotinate (keto
tazarotene)
6-(4,4-Dimethyl-1-oxo-1.lamda..sup.4-thiochroman-6-ylethynyl)nicotinic
acid ethyl ester
[0264] A suspension of tazarotene (10.0 g, 28.5 mmol) in methanol
(300 mL) was chilled in an ice water bath to <10.degree. C., and
then charged with the dropwise addition of a solution of NaIO.sub.4
(9.13 g, 42.7 mmol) in water (100 mL) over 30 minutes. The reaction
was allowed to warm to room temperature while stirring for 18
hours, and was then concentrated under reduced pressure to remove
as much methanol as possible. The reaction was then diluted with
DCM (500 mL) and water (150 mL). The two layers were then
separated, and the aqueous layer was extracted with DCM
(2.times.100 mL aliquots). The organic fractions were pooled, dried
over Na.sub.2SO.sub.4, filtered, and concentrated under reduced
pressure. The crude sulfoxide product was then chromatographed
using a DCM:EtOAc solvent system. Yield: 9.00 g (86%).
[0265] .sup.1H NMR (400 MHz, CDCl.sub.3) .delta. ppm 1.34 (s, 3H),
1.43 (t, J=7.1 Hz, 3H), 1.47 (s, 3H), 1.91 (ddd, J=15.1, 8.9, 2.3
Hz, 1H), 2.45 (ddd, J=15.1, 10.3, 2.4 Hz, 1H), 3.04-3.29 (m, 2H),
4.44 (q, J=7.1 Hz, 2H), 7.58 (dd, J=8.1, 1.6 Hz, 1H), 7.63 (dd,
J=8.2, 0.7 Hz, 1H), 7.71 (d, J=1.6 Hz, 1H), 7.78 (d, J=8.1 Hz, 1H),
8.32 (dd, J=8.2, 2.2 Hz, 1H), 9.22 (dd, J=2.1, 0.7 Hz, 1H). MS
(ESI+) 368.0.
6-(2-Acetoxy-4,4-dimethylthiochroman-6-ylethynyl)nicotinic acid
ethyl ester
[0266] A solution of the above sulfoxide (9.00 g, 24.5 mmol) in
acetic anhydride (185 mL) was heated to 130.degree. C. for 5 hours,
then concentrated under reduced procedure, with toluene added to
aid evaporation of the acetic anhydride. The crude acetate was then
chromatographed on a silica plug using a heptane:EtOAc solvent
system. Yield: 8.47 g (84%).
[0267] .sup.1H NMR (400 MHz, CDCl.sub.3) .delta. ppm 1.40 (s, 3H),
1.43 (t, J=7.2 Hz, 3H), 1.46 (s, 3H), 2.10-2.22 (m, 2H), 2.11 (s,
3H), 4.43 (q, J=7.1 Hz, 2H), 6.22 (dd, J=6.9, 5.2 Hz, 1H), 7.11 (d,
J=8.1 Hz, 1H), 7.34 (dd, J=8.2, 1.8 Hz, 1H), 7.58 (dd, J=8.2, 0.8
Hz, 1H), 7.64 (d, J=1.7 Hz, 1H), 8.29 (dd, J=8.2, 2.2 Hz, 1H), 9.20
(dd, J=2.2, 0.8 Hz, 1H). MS (ESI+) 410.0.
6-(2-Hydroxy-4,4-dimethylthiochroman-6-ylethynyl)nicotinic acid
ethyl ester
[0268] A solution of the above acetate (3.29 g, 8.03 mmol) in THF
(50 mL) was charged with NaOEt (2.18 g, 32.1 mmol), and the
reaction was heated to 75.degree. C. for 12 hours. The reaction was
then diluted with EtOAc (250 mL) and washed with water (2.times.100
mL aliquots). The aqueous washes were then pooled and
back-extracted with EtOAc (2.times.100 mL aliquots). The organic
fractions were pooled, dried over Na.sub.2SO.sub.4, filtered, and
concentrated under reduced pressure to give the thiolactol. Yield:
2.31 g (78%).
[0269] .sup.1H NMR (400 MHz, CDCl.sub.3) .delta. ppm 1.31 (s, 3H),
1.43 (t, J=7.1 Hz, 3H), 1.48 (s, 3H), 1.95-2.07 (m, 1H), 2.26 (dd,
J=13.5, 4.5 Hz, 1H), 2.54 (d, J=8.5 Hz, 1H), 4.43 (q, J=7.2 Hz,
2H), 5.50 (td, J=8.8, 4.5 Hz, 1H), 7.09 (d, J=8.2 Hz, 1H), 7.32
(dd, J=8.1, 1.8 Hz, 1H), 7.58 (dd, J=8.2, 0.8 Hz, 1H), 7.62 (d,
J=1.7 Hz, 1H), 8.28 (dd, J=8.2, 2.2 Hz, 1H), 9.20 (dd, J=2.2, 0.8
Hz, 1H).
ethyl 6-((4,4-dimethyl-2-oxothiochroman-6-yl)ethynyl)nicotinate
[0270] A solution of the above thiolactol (2.31 g, 6.29 mmol) in
DCM (500 mL) was charged with Dess-Martin periodinane (2.80 g, 6.60
mmol), and the reaction stirred at room temperature for 1 hour. The
reaction was then concentrated under reduced pressure, then diluted
with EtOAc (250 mL) and washed with a saturated aqueous NaHCO.sub.3
solution (2.times.100 mL aliquots). The aqueous washes were then
pooled and back-extracted with EtOAc (2.times.200 mL). The organic
fractions were then pooled, dried over Na.sub.2SO.sub.4, filtered,
and concentrated under reduced pressure. The crude product was then
chromatographed on a silica plug using a heptane:EtOAc solvent
system. Yield: 1.28 g (56%).
[0271] .sup.1H NMR (400 MHz, CDCl.sub.3) .delta. ppm 1.44 (t, J=7.2
Hz, 3H), 1.44 (s, 6H), 2.71 (s, 2H), 4.44 (q, J=7.1 Hz, 2H), 7.23
(d, J=8.1 Hz, 1H), 7.48 (dd, J=8.1, 1.7 Hz, 1H), 7.62 (dd, J=8.1,
0.8 Hz, 1H), 7.73 (d, J=1.7 Hz, 1H), 8.31 (dd, J=8.2, 2.2 Hz, 1H),
9.22 (dd, J=2.2, 0.8 Hz, 1H).
Compound 13--Ethyl
6-[2-palmitoyl-4,4-dimethyl-3,4-dihydro-2-thiochromen-6-yl)ethynyl]pyridi-
ne-3-carboxylate
[0272] Ethyl
6-[2-hydroxy-4,4-dimethyl-3,4-dihydro-2-thiochromen-6-yl)ethynyl]pyridine-
-3-carboxylate (hydroxy tazarotene) was reacted with palmitoyl
chloride in DCM and TEA at room temperature. The crude product was
purified by column chromatography to give the desired compound.
[0273] .sup.1H NMR (400 MHz, CHLOROFORM-d) .delta. 0.85 (d, J=13.57
Hz, 2H), 0.85 (s, 2H), 1.22 (s, 26H), 1.29 (br. s, 6H), 1.35-1.50
(m, 11H), 1.56 (s, 2H), 1.63 (br. s, 1H), 1.60 (d, J=7.42 Hz, 2H),
2.03-2.20 (m, 2H), 2.31 (d, J=15.03 Hz, 1H), 2.31 (s, 1H), 4.40 (q,
J=7.13 Hz, 2H), 6.19 (dd, J=6.49, 5.32 Hz, 1H) 7.07 (d, J=8.10 Hz,
1H), 7.31 (dd, J=8.15, 1.61 Hz, 1H), 7.55 (d, J=8.10 Hz, 1H), 7.61
(d, J=1.56 Hz, 1H), 8.25 (dd, J=8.15, 2.10 Hz, 1H), 9.17 (d, J=1.56
Hz, 1H)
Compound 14--Ethyl
6-[(2-hydroxy-4,4-dimethyl-3,4-dihydro-2-thiochromen-6-yl)ethynyl]pyridin-
e-3-carboxylate (hydroxy tazarotene)
[0274] Hydrolysis of compound 17 with sodium ethoxide in refluxing
THF gave a mixture of the title compound, along with compound 10.
The title compound was obtained (51%) by column chromatographic
purification to remove the non-polar impurities and compound 10
(the hydroxy acid).
[0275] .sup.1H NMR (400 MHz, CHLOROFORM-d) .delta. 1.25 (s, 3H),
1.38 (t, J=7.13 Hz, 3H), 1.42 (s, 3H), 1.98 (dd, J=13.42, 9.32 Hz,
1H), 2.21 (dd, J=13.47, 4.49 Hz, 1H), 3.21 (d, J=8.10 Hz, 1H), 4.39
(q, J=7.13 Hz, 2H), 5.48 (dt, J=13.03, 4.47 Hz, 1H), 7.02 (d,
J=8.10 Hz, 1H), 7.26 (dd, J=8.10, 1.56 Hz, 1H), 7.53 (d, J=8.20 Hz,
1H), 7.57 (d, J=1.46 Hz, 1H), 8.24 (dd, J=8.15, 2.10 Hz, 1H), 9.15
(d, J=1.56 Hz, 1H)
Compound
15--6-[2-(2-Hydroxy-acetoxy)-4,4-dimethyl-thiochroman-6-ylethynyl-
]-nicotinic acid ethyl ester
[0276] Glycolic acid (4.2 g, 0.05 mole) and
tert-butyldimethylchlorosilane (17.7 g, 0.012 mole) were stirred in
40 mL of dry DMF. Imidazole (15.62 g, 0.23 mol) was added to the
mixture and stirred under nitrogen for 18 hours. The mixture was
poured into deionized water (approximately 250 mL) and extracted
with diethyl ether (3.times.100 mL aliquots). The organic fractions
were combined, washed with saturated NaHCO.sub.3, dried over MgSO4,
and concentrated in vacuo to give an oil. Further drying under high
vacuum provided 10.7 g (91%) of the bis-silylated glycolic acid as
a white solid.
[0277] The bis-silylated glycolic acid was dissolved in 125 mL of
dry DCM containing several drops of DMF. A solution of 13.4 mL
oxalyl chloride (148 mmoles, 4.5 equivalents) was added drop wise
under nitrogen for 20 minutes. The mixture was stirred for 4 hours
at ambient temperature, then concentrated under vacuum to remove
the volatiles (unreacted oxalyl chloride) to give the crude acid
chloride (tert-butyldimethyl-silyloxy glycolic acid chloride) as a
yellow oil.
[0278] A solution of Ethyl
6-[(2-hydroxy-4,4-dimethyl-3,4-dihydro-2-thiochromen-6-yl)ethynyl]pyridin-
e-3-carboxylate (hydroxy tazarotene) (400 mg, 1 mmole)) in DCM/TEA
at room temperature was prepared. The mixture was placed under a
nitrogen atmosphere and the above acid chloride (340 mg, 1.5
mmoles, 1.5 equivalents) was added slowly at room temperature. The
mixture was stirred at ambient temperature for 17 hours after which
time, LCMS analysis showed complete conversion. The mixture was
diluted with DCM (50 mL) and washed with H.sub.2O (15 mL) followed
by saturated NaHCO.sub.3 (15 mL) and brine solution. The organic
layer was dried over Na.sub.2SO.sub.4, filtered and concentrated to
an oil--a silylated intermediate. Chromatography on silica gel
eluting with an ethyl acetate-heptanes gradient gave 300 mg of
purified product.
[0279] The silylated intermediate was dissolved in THF (4 mL) and
acetic acid (0.5 mL). The stirring mixture was treated with 1M TBAF
(1 mL, 1 mmole) and stirred for 1 hour at ambient temperature. The
crude reaction mixture was concentrated to an oil. The oil was
treated with heptanes (5 mL) and kept cold (.about.4.degree. C.)
overnight. The resulting solid was filtered and washed with
heptanes to give 130 mg (29%) of compound 15 as a white translucent
solid.
[0280] .sup.1H NMR (400 MHz, CHLOROFORM-d) .delta. 1.36-1.51 (m,
11H), 2.10-2.29 (m, 2H), 2.35 (t, J=5.66 Hz, 1H), 4.21 (d, J=5.66
Hz, 2H), 4.37-4.50 (m, 2H), 6.36 (dd, J=6.59, 5.32 Hz, 1H), 7.11
(d, J=8.10 Hz, 1H), 7.36 (dd, J=8.10, 1.56 Hz, 1H), 7.59 (d, J=8.20
Hz, 1H), 7.65 (d, J=1.46 Hz, 1H), 8.29 (dd, J=8.15, 2.10 Hz, 1H),
9.21 (d, J=1.46 Hz, 1H)
Compound 16--Ethyl
6-[(2-(2-methoxyacetyl)-4,4-dimethyl-3,4-dihydro-2-thiochromen-6-yl)ethyn-
yl]pyridine-3-carboxylate
[0281] Ethyl
6-[2-hydroxy-4,4-dimethyl-3,4-dihydro-2-thiochromen-6-yl)ethynyl]pyridine-
-3-carboxylate (hydroxy tazarotene) was reacted with methoxyacetyl
chloride in DCM/TEA at room temperature. The crude product was
purified by column chromatography to give the desired compound.
[0282] .sup.1H NMR (400 MHz, CHLOROFORM-d) .delta. 1.43 (d, J=14.45
Hz, 7H), 1.43 (s, 2H), 2.09-2.34 (m, 2H), 3.46 (s, 3H), 4.07 (s,
2H), 4.43 (q, J=7.19 Hz, 2H), 6.33 (dd, J=6.64, 5.27 Hz, 1H), 7.11
(d, J=8.20 Hz, 1H), 7.35 (dd, J=8.15, 1.61 Hz, 1H), 7.58 (d, J=8.10
Hz, 1H), 7.64 (d, J=1.46 Hz, 1H), 8.28 (dd, J=8.15, 2.10 Hz, 1H),
9.20 (d, J=1.46 Hz, 1H)
Compound 17--Ethyl
6-[(2-acetyl-4,4-dimethyl-3,4-dihydro-2-thiochromen-6-yl)ethynyl]pyridine-
-3-carboxylate
[0283] Tazarotene was oxidized with sodium periodate in
methanol/water to give the corresponding sulfoxide. After column
purification it yielded 47 g (90%) of the sulfoxide, which was
subjected to Pummerer rearrangement with acetic anhydride as the
solvent and acylating agent to yield the desired product (42
g).
[0284] .sup.1H NMR (400 MHz, CHLOROFORM-d) .delta. 1.39 (s, 4H),
1.41 (s, 2H) 1.43-1.49 (m, 4H), 2.10 (s, 3H), 2.11-2.18 (m, 2H),
4.42 (q, J=7.13 Hz, 2H), 6.20 (dd, J=6.69, 5.42 Hz, 1H), 7.09 (d,
J=8.10 Hz, 1H), 7.33 (dd, J=8.10, 1.37 Hz, 1H), 7.57 (d, J=8.10 Hz,
1H), 7.63 (d, J=1.27 Hz, 1H), 8.27 (dd, J=8.15, 2.00 Hz, 1H), 9.19
(d, J=1.37 Hz, 1H)
Compound 18--Ethyl
6-[(2-n-butyryloxyl-4,4-dimethyl-3,4-dihydro-2-thiochromen-6-yl)ethynyl]p-
yridine-3-carboxylate
[0285] Ethyl
6-[2-hydroxy-4,4-dimethyl-3,4-dihydro-2-thiochromen-6-yl)ethynyl]pyridine-
-3-carboxylate (hydroxy tazarotene) was reacted with butyryl
chloride in DCM/TEA at room temperature. The crude product was
purified by column chromatography to give the desired compound.
[0286] .sup.1H NMR (400 MHz, CHLOROFORM-d) .delta. 0.97 (t, J=7.42
Hz, 4H), 1.38-1.50 (m, 11H), 1.63-1.74 (m, 3H), 2.15 (d, J=6.83 Hz,
1H), 2.17 (d, J=5.27 Hz, 1H), 2.33 (d, J=15.13 Hz, 1H), 2.34 (s,
1H), 4.43 (q, J=7.13 Hz, 2H), 6.23 (dd, J=6.49, 5.42 Hz, 1H), 7.11
(d, J=8.10 Hz, 1H), 7.34 (dd, J=8.10, 1.56 Hz, 1H), 7.58 (d, J=8.10
Hz, 1H), 7.64 (d, J=1.37 Hz, 1H), 8.29 (dd, J=8.15, 2.10 Hz, 1H),
9.21 (d, J=1.56 Hz, 1H)
Compound 19--Ethyl
6-[(2-lauroyl-4,4-dimethyl-3,4-dihydro-2-thiochrornen-6-yl)ethynyl]pyridi-
ne-3-carboxylate
[0287] Ethyl
6-[2-hydroxy-4,4-dimethyl-3,4-dihydro-2-thiochromen-6-yl)ethynyl]pyridine-
-3-carboxylate (hydroxy tazarotene) was reacted with lauroyl
chloride in DCM/TEA at room temperature. The crude product was
purified by column chromatography to give the desired compound.
[0288] .sup.1H NMR (400 MHz, CHLOROFORM-d) .delta. 0.88 (d, J=13.71
Hz, 2H), 0.88 (s, 2H), 1.20-1.38 (m, 4H), 1.26 (s, 18H), 1.41 (s,
4H), 1.43 (s, 2H), 1.44-1.49 (m, 4H), 1.57-1.73 (m, 4H), 2.14 (d,
J=6.74 Hz, 1H), 2.17 (d, J=5.22 Hz, 1H), 2.31-2.39 (m, 2H), 4.43
(q, J=7.11 Hz, 2H), 6.22 (dd, J=6.64, 5.22 Hz, 1H), 7.10 (d, J=8.15
Hz, 1H), 7.34 (dd, J=8.13, 1.73 Hz, 1H), 7.58 (dd, J=8.15, 0.83 Hz,
1H), 7.64 (d, J=1.71 Hz, 1H), 8.28 (dd, J=8.15, 2.15 Hz, 1H), 9.20
(dd, J=2.15, 0.78 Hz, 1H)
Compound 20--Ethyl
6-[(2-isobutyryloxy-4,4-dimethyl-3,4-dihydro-2-thiochrornen-6-yl)ethynyl]-
pyridine-3-carboxylate
[0289] Ethyl
6-[2-hydroxy-4,4-dimethyl-3,4-dihydro-2-thiochromen-6-yl)ethynyl]pyridine-
-3-carboxylate (hydroxy tazarotene) was reacted with isobutyryl
chloride in DCM/TEA at room temperature. The crude product was
purified by column chromatography to give the desired compound.
[0290] .sup.1H NMR (400 MHz, CHLOROFORM-d) .delta. 0.74-0.98 (m,
4H), 1.20 (d, J=7.03 Hz, 7H), 1.44 (d, J=14.15 Hz, 6H), 1.43 (t,
J=7.13 Hz, 5H), 2.17 (d, J=4.39 Hz, 2H), 2.15 (s, 1H) 2.49-2.66 (m,
1H), 4.44 (q, J=7.13 Hz, 2H) 6.16-6.26 (m, 1H), 7.11 (d, J=8.10 Hz,
1H), 7.34 (dd, J=8.10, 1.46 Hz, 1H), 7.59 (d, J=8.20 Hz, 1H), 7.65
(d, J=1.37 Hz, 1H), 8.29 (dd, J=8.10, 2.05 Hz, 1H), 9.21 (d, J=1.46
Hz, 1H)
Compound 21--Ethyl
6-[(2-linoeoyll-4,4-dimethyl-3,4-dihydro-2-thiochrornen-6-yl)ethynyl]pyri-
dine-3-carboxylate
[0291] Ethyl
6-[2-hydroxy-4,4-dimethyl-3,4-dihydro-2-thiochromen-6-yl)ethynyl]pyridine-
-3-carboxylate (hydroxy tazarotene) was reacted with linoleoyl
chloride in DCM/TEA at room temperature. The crude product was
purified by column chromatography to give the desired compound.
[0292] .sup.1H NMR (400 MHz, CHLOROFORM-d) .delta. 0.76-0.97 (m,
9H), 1.19-1.39 (m, 26H), 1.40-1.50 (m, 15H), 1.67 (br. s, 1H), 1.64
(d, J=7.32 Hz, 2H), 2.03 (br. s, 1H), 2.05 (d, J=6.74 Hz, 5H), 2.15
(d, J=6.83 Hz, 2H), 2.17 (d, J=5.27 Hz, 1H), 2.35 (d, J=14.93 Hz,
2H), 2.35 (s, 1H), 2.78 (d, J=12.49 Hz, 1H), 2.78 (s, 1H), 4.44 (q,
J=7.13 Hz, 3H), 5.27-5.45 (m, 6H), 6.23 (dd, J=6.54, 5.37 Hz, 1H),
7.11 (d, J=8.10 Hz, 1H) 7.34 (dd, J=8.10, 1.56 Hz, 1H), 7.59 (d,
J=8.20 Hz, 1H), 7.64 (d, J=1.46 Hz, 1H), 8.29 (dd, J=8.15, 2.10 Hz,
1H)
Compound 22--Ethyl
6-[(2-linleolyl-4,4-dimethyl-3,4-dihydro-2-thiochrornen-6-yl)ethynyl]pyri-
dine-3-carboxylate
[0293] Ethyl
6-[2-hydroxy-4,4-dimethyl-3,4-dihydro-2-thiochromen-6-yl)ethynyl]pyridine-
-3-carboxylate (hydroxy tazarotene) was reacted with linolenoyl
chloride in DCM/TEA at room temperature. The crude product was
purified by column chromatography to give the desired compound.
[0294] .sup.1H NMR (400 MHz, CHLOROFORM-d) .delta. 0.98 (t, J=7.52
Hz, 4H), 1.22-1.38 (m, 14H), 1.38-1.50 (m, 13H), 1.66 (br. s, 1H),
1.64 (d, J=7.22 Hz, 2H), 2.01-2.22 (m, 9H), 2.35 (t, J=7.52 Hz,
3H), 2.69-2.93 (m, 6H), 4.44 (q, J=7.13 Hz, 3H), 5.28-5.45 (m, 9H),
6.23 (dd, J=6.54, 5.37 Hz, 1H), 7.11 (d, J=8.10 Hz, 1H), 7.34 (dd,
J=8.10, 1.56 Hz, 1H), 7.59 (d, J=8.20 Hz, 1H), 7.64 (d, J=1.56 Hz,
1H), 8.29 (dd, J=8.15, 2.10 Hz, 1H)
Compound 23--Ethyl
6-[(2-(N-methyl-4-piperidinylcarboxy-4,4-dimethyl-3,4-dihydro-2-thiochror-
nen-6-yl)ethynyl]pyridine-3-carboxylate
[0295] Ethyl
6-[2-hydroxy-4,4-dimethyl-3,4-dihydro-2-thiochromen-6-yl)ethynyl]pyridine-
-3-carboxylate (hydroxy tazarotene) was reacted with 1-methyl
piperidine carbonyl chloride in DCM/TEA at room temperature. The
crude product was purified by column chromatography to give the
desired compound.
[0296] .sup.1H NMR (400 MHz, CHLOROFORM-d) .delta. 1.35-1.50 (m,
11H), 1.70-1.85 (m, 1H), 1.78 (dd, J=11.23, 1.46 Hz, 2H), 1.85-2.06
(m, 5H), 2.14 (d, J=11.81 Hz, 1H), 2.14 (s, 1H), 2.21-2.36 (m, 1H),
2.25 (s, 4H), 2.79 (d, J=11.23 Hz, 2H), 4.42 (q, J=7.13 Hz, 2H),
6.15-6.26 (m, 1H), 7.09 (d, J=8.10 Hz, 1H), 7.33 (dd, J=8.10, 1.56
Hz, 1H), 7.57 (d, J=8.20 Hz, 1H), 7.63 (d, J=1.37 Hz, 1H), 8.27
(dd, J=8.15, 2.10 Hz, 1H), 9.19 (d, J=1.46 Hz, 1H)
Compound 24--Ethyl
6-[(2-propionyl-4,4-dimethyl-3,4-dihydro-2-thiochrornen-6-yl)ethynyl]pyri-
dine-3-carboxylate
[0297] Ethyl
6-[2-hydroxy-4,4-dimethyl-3,4-dihydro-2-thiochromen-6-yl)ethynyl]pyridine-
-3-carboxylate (hydroxy tazarotene) was reacted with propionyl
chloride in DCM with TEA as a base at room temperature. The crude
product was purified by column chromatography to give the desired
compound.
[0298] .sup.1H NMR (400 MHz, CHLOROFORM-d) .delta. 1.17 (t, J=7.56
Hz, 4H), 1.34-1.51 (m, 11H), 2.15 (d, J=6.74 Hz, 1H), 2.17 (d,
J=5.27 Hz, 1H), 2.38 (q, J=7.58 Hz, 2H), 4.43 (q, J=7.13 Hz, 2H),
6.23 (dd, J=6.59, 5.32 Hz, 1H), 7.11 (d, J=8.10 Hz, 1H), 7.34 (dd,
J=8.10, 1.56 Hz, 1H), 7.59 (d, J=8.10 Hz, 1H), 7.64 (d, J=1.46 Hz,
1H), 8.29 (dd, J=8.20, 2.15 Hz, 1H), 9.21 (d, J=1.56 Hz, 1H)
Compound 25--Ethyl
6-[(2-salicylicyl-4,4-dimethyl-3,4-dihydro-2-thiochrornen-6-yl)ethynyl]py-
ridine-3-carboxylate
[0299] Ethyl
6-[2-hydroxy-4,4-dimethyl-3,4-dihydro-2-thiochromen-6-yl)ethynyl]pyridine-
-3-carboxylate (hydroxy tazarotene) was reacted with salicylic acid
using EDC and HOBt. The reaction afforded the desired compound,
along with a self coupled impurity. The desired product was
obtained via column chromatography.
[0300] .sup.1H NMR (400 MHz, CHLOROFORM-d) .delta. 1.40 (t, J=7.13
Hz, 7H), 1.47 (s, 7H), 1.52 (s, 8H), 2.29 (d, J=1.56 Hz, 2H), 2.31
(d, J=2.44 Hz, 2H), 4.41 (q, J=7.06 Hz, 4H), 6.47 (t, J=5.51 Hz,
2H), 6.79-6.92 (m, 2H), 6.98 (d, J=8.30 Hz, 2H), 7.10 (d, J=8.10
Hz, 2H), 7.34 (dd, J=8.10, 1.37 Hz, 2H), 7.46 (s, 2H), 7.57 (d,
J=8.10 Hz, 2H), 7.66 (d, J=1.17 Hz, 2H), 7.76 (dd, J=7.96, 1.32 Hz,
2H), 8.26 (dd, J=8.10, 2.05 Hz, 2H), 9.18 (d, J=1.37 Hz, 2H), 10.53
(s, 1H)
Compound 26--Ethyl
6-[(2-(4-tetrahydropyranyloxy-4,4-dimethyl-3,4-dihydro-2-thiochrornen-6-y-
l)ethynyl]pyridine-3-carboxylate
[0301] Ethyl
6-[2-hydroxy-4,4-dimethyl-3,4-dihydro-2-thiochromen-6-yl)ethynyl]pyridine-
-3-carboxylate (hydroxy tazarotene) was reacted with
tetrahydropyran-4-carbonyl chloride in DCM/TEA at room temperature.
The crude product was purified by column chromatography to give the
desired compound.
[0302] .sup.1H NMR (400 MHz, CHLOROFORM-d) .delta. 1.31-1.50 (m,
11H), 1.69-1.92 (m, 5H), 2.04-2.26 (m, 2H), 2.55 (t, J=10.54 Hz,
1H), 3.32-3.48 (m, 2H), 3.94 (dd, J=11.47, 2.88 Hz, 2H), 4.41 (q,
J=7.13 Hz, 2H), 6.14-6.28 (m, 1H), 7.08 (d, J=8.10 Hz, 1H), 7.32
(dd, J=8.10, 1.46 Hz, 1H), 7.56 (d, J=8.10 Hz, 1H), 7.62 (d, J=1.27
Hz, 1H), 8.26 (dd, J=8.20, 2.05 Hz, 1H), 9.18 (d, J=1.37 Hz,
1H)
Compound 27--Ethyl
6-[(2-monomethyladopyl-4,4-dimethyl-3,4-dihydro-2-thiochromen-6-yl)ethyny-
l]pyridine-3-carboxylate
[0303] Ethyl
6-[2-hydroxy-4,4-dimethyl-3,4-dihydro-2-thiochromen-6-yl)ethynyl]pyridine-
-3-carboxylate (hydroxy tazarotene) was reacted with monomethyl
adipoyl chloride in DCM/TEA at room temperature. The crude product
was purified by column chromatography to give the desired
compound.
[0304] .sup.1H NMR (400 MHz, CHLOROFORM-d) .delta. 1.40 (d, J=16.40
Hz, 8H), 1.40 (s, 3H), 1.66 (d, J=14.06 Hz, 1H), 1.66 (t, J=3.42
Hz, 3H), 2.05-2.21 (m, 2H), 2.25-2.42 (m, 4H), 3.64 (s, 3H), 4.40
(q, J=7.13 Hz, 2H), 6.19 (dd, J=6.59, 5.32 Hz, 1H), 7.07 (d, J=8.10
Hz, 1H), 7.31 (dd, J=8.10, 1.56 Hz, 1H), 7.55 (d, J=8.20 Hz, 1H),
7.61 (d, J=1.46 Hz, 1H), 8.26 (dd, J=8.10, 2.15 Hz, 1H), 9.17 (d,
J=1.46 Hz, 1H)
Compound 28--Ethyl
6-[(2-(3-monomethylazelauate-4,4-dimethyl-3,4-dihydro-2-thiochrornen-6-yl-
)ethynyl]pyridine-3-carboxylate
[0305] Ethyl
6-[2-hydroxy-4,4-dimethyl-3,4-dihydro-2-thiochromen-6-yl)ethynyl]pyridine-
-3-carboxylate (hydroxy tazarotene) was reacted with monomethyl
azelate chloride in DCM/TEA at room temperature. The crude product
was purified by column chromatography to give the desired
compound.
[0306] .sup.1H NMR (400 MHz, CHLOROFORM-d) .delta. 1.32 (br. s.,
11H), 1.39-1.50 (m, 11H), 1.53-1.73 (m, 7H), 2.15 (d, J=6.74 Hz,
2H), 2.17 (d, J=5.17 Hz, 1H), 2.26-2.46 (m, 7H), 3.58-3.77 (m, 5H),
4.44 (q, J=7.13 Hz, 2H), 6.22 (dd, J=6.54, 5.37 Hz, 1H), 7.11 (d,
J=8.20 Hz, 1H), 7.34 (dd, J=8.10, 1.56 Hz, 1H), 7.59 (d, J=8.20 Hz,
1H), 7.64 (d, J=1.46 Hz, 1H), 8.29 (dd, J=8.15, 2.10 Hz, 1H), 9.21
(d, J=1.46 Hz, 1H)
Compound
29--6-[2-((S)-2-Amino-3-methyl-butyryloxy)-4,4-dimethyl-thiochrom-
an-6-ylethynyl]-nicotinic acid ethyl ester
[0307] Ethyl
6-[2-hydroxy-4,4-dimethyl-3,4-dihydro-2-thiochromen-6-yl)ethynyl]pyridine-
-3-carboxylate (hydroxy tazarotene) was reacted with Fmoc protected
amino acid chloride (from Valine) to give the Fmoc protected amino
ester. Fmoc deprotection was facilitated with dilute piperidine in
THF at room temperature, as follows:
[0308] 20% Piperidine (5 equivalents) in THF was added to a
solution of the Fmoc-protected amino ester in THF, while stirring.
The reaction mixture was stirred for 5 hours and progress of the
reaction was periodically monitored by LC/MS. At completion of the
reaction, the reaction mixture was poured into water and extracted
with EtOAc (2.times.20 mL aliquots). The organic layers were
combined, washed with brine, dried over anhydrous Na.sub.2SO.sub.4,
concentrated and purified in a Companion purification system using
a 12.0 g cartridge.
[0309] .sup.1H NMR (400 MHz, CHLOROFORM-d) .delta. 0.92 (t, J=6.78
Hz, 3H), 0.99 (d, J=6.74 Hz, 3H), 1.35-1.59 (m, 12H), 1.97-2.09 (m,
1H), 2.09-2.26 (m, 2H), 3.31 (d, J=5.17 Hz, 1H), 4.43 (q, J=7.06
Hz, 2H), 6.20-6.34 (m, 1H), 7.10 (d, J=8.10 Hz, 1H), 7.34 (d,
J=8.10 Hz, 1H), 7.58 (d, J=8.20 Hz, 1H), 7.64 (d, J=1.27 Hz, 1H),
8.28 (dd, J=8.10, 2.05 Hz, 1H), 9.20 (d, J=1.56 Hz, 1H)
TABLE-US-00012 TABLE 11 Description Structure Notes 1 Untreated
(negative) NA None control 2 OD (vehicle) control NA None 3
Tazarotene (0.1% in OD) ##STR00005## MW 351.46 Purity 99.5% 4
Tazarotene benzoate 6-(2-(2-benzoyloxy-4,4- dimethylthiochroman-6-
yl)ethynyl)nicotinic acid, ethyl ester ##STR00006## MW 471.58
Purity 98.0% 5 Tazarotene benzoate (S isomer) (S)-6-(2-(2-
benzoyloxy-4,4- dimethylthiochroman-6- yl)ethynyl)nicotinic acid,
ethyl ester ##STR00007## MW 471.58 Purity >97.0% 6 Tazarotene
benzoate (R isomer) (R)-6-(2-(2- benzoyloxy-4,4-
dimethylthiochroman-6- yl)ethynyl)nicotinic acid, ethyl ester
##STR00008## MW 471.58 Purity >97.0% 7 Tazarotene nicotinate
6-[4,4-Dimethyl-2- (pyridine-3-carbonyloxy) thiochroman-6-
ylethynyl]nicotinic acid ethyl ester ##STR00009## MW 472.57 Purity
94.0% 8 Tazarotene nicotinate (S isomer) S-6-[4,4-Dimethyl-2-
(pyridine-3-carbonyloxy) thiochroman-6- ylethynyl]nicotinic acid
ethyl ester ##STR00010## MW 472.56 Purity 95.0% 9 Tazarotene
nicotinate (R isomer) R-6-[4,4-Dimethyl-2- (pyridine-3-carbonyloxy)
thiochroman-6- ylethynyl]nicotinic acid ethyl ester ##STR00011## MW
472.56 Purity 95.0% 10 Hydroxy tazarotenic acid 6-((2-hydroxy-4,4-
dimethylthiochroman-6- yl)ethynyl)nicotinic acid ##STR00012## MW
339.42 Purity 99.3% 11 Keto tazarotenic acid 6-((4,4-dimethyl-2-
oxothiochroman-6- yl)ethynyl)nicotinic acid ##STR00013## MW 337.40
Purity 87.0% 12 Keto tazarotene Ethyl 6-((4,4-dimethyl-
2-oxothiochroman-6- yl)ethynyl)nicotinate ##STR00014## MW 406.00
Purity 99.0% 13 Ethyl 6-[2-palmitoyl-4,4- dimethyl-3,4-dihydro-2-
thiochromen-6-yl) ethynyl]pyridine-3- carboxylate ##STR00015## MW
605.89 Purity 94.8% 14 Hydroxy Tazarotene Ethyl 6-[(2-hydroxy-4,4-
dimethyl-3,4-dihydro-2- thiochromen-6-yl)ethyynyl]
pyridine-3-carboxylate ##STR00016## MW 367.47 Purity 98.4% 15
6-[2-(2-Hydroxy-acetoxy)- 4,4-dimethyl-thiochroman-
6-ylethynyl]-nicotinic acid ethyl ester ##STR00017## MW 425.50
Purity >99.5% 16 Ethyl 6-[(2-(2- methoxyacetyl)-4,4-
dimethyl-3,4-dihydro-2- thiochromen-6-yl)ethynyl]
pyridine-3-carboxylate ##STR00018## MW 439.53 Purity 96.3% 17 Ethyl
6-[(2-acetyl-4,4- dimethyl-3,4-dihydro-2- thiochromen-6-yl)ethynyl]
pyridine-3-carboxylate ##STR00019## MW 409.51 Purity 95.4% 18 Ethyl
6-[(2-n-butyryloxyl- 4,4-dimethyl-3,4-dihydro- 2-thiochromen-6-yl)
ethynyl]pyridine-3- carboxylate ##STR00020## MW 437.56 Purity 98.4%
19 Ethyl 6-[(2-lauroyl-4,4- dimethyl-3,4-dihydro-2-
thiochrornen-6-yl)ethynyl] pyridine-3-carboxylate ##STR00021## MW
549.78 Purity 98.5% 20 Ethyl 6-[(2-isobutyryloxy-
4,4-dimethyl-3,4-dihydro- 2-thiochrornen-6-yl) ethynyl]pyridine-3-
carboxylate ##STR00022## MW 437.56 Purity 98.4% 21 Ethyl
6-[(2-linoeoyll-4,4- dimethyl-3,4-dihydro-2-
thiochrornen-6-yl)ethynyl] pyridine-3-carboxylate ##STR00023## MW
629.91 Purity 98.3% 22 Ethyl 6-[(2-linleolyl-4,4-
dimethyl-3,4-dihydro-2- thiochrornen-6-yl)ethynyl]
pyridine-3-carboxylate ##STR00024## MW 627.89 Purity 96.1% 23 Ethyl
6-[(2-(N-methyl-4- piperidinylcarboxy-4,4- dimethyl-3,4-dihydro-2-
thiochrornen-6-yl)ethynyl] pyridine-3-carboxylate ##STR00025## MW
492.64 Purity 94.9% 24 Ethyl 6-[(2-propionyl-4,4-
dimethyl-3,4-dihydro-2- thiochrornen-6-yl)ethynyl]
pyridine-3-carboxylate ##STR00026## MW 423.54 Purity 98.7% 25 Ethyl
6-[(2-salicylicyl-4,4- dimethyl-3,4-dihydro-2-
thiochrornen-6-yl)ethynyl] pyridine-3-carboxylate ##STR00027## MW
487.58 Purity 98.7% 26 Ethyl 6-[(2-(4- tetrahydropyranyloxy-4,4-
dimethyl-3,4-dihydro-2- thiochrornen-6-yl)ethynyl]
pyridine3-carboxylate ##STR00028## MW 479.60 Purity 98.3% 27 Ethyl
6-[(2- monomethyladopyl-4,4- dimethyl-3,4-dihydro-2-
thiochrornen-6-yl)ethynyl] pyridine3-carboxylate ##STR00029## MW
509.63 Purity 99.5% 28 Ethyl 6-[(2-(3- monomethylazelauate-4,4-
dimethyl-3,4-dihydro-2- thiochrornen-6-yl)ethynyl]
pyridine3-carboxylate ##STR00030## MW 551.71 Purity 95.3% 29
6-[2-((S)-2-Amino-3- methyl-butyryloxy)-4,4-
dimethyl-thiochroman-6- ylethynyl]-nicotinic acid ethyl ester
##STR00031## MW 466.60 Purity 97.8%
TABLE-US-00013 TABLE 12 Qualitative summary of gene expression data
from RHE cultures treated with tazarotene derivatives. Fold Change
vs Untreated/OD controls Upregulation/Downregulation Ranking Rank
Compound K10 K19 Filaggrin K4 K13 Score 1 24 14 33 56 74 23 20 2 23
9 43 18 73 19 23 3 11 17 21 36 52 20 27 4 29 9 29 11 71 13 31 5 15
7 36 8 64 12 33 6 27 10 41 23 70 19 40 7 28 6 30 7 77 18 43 8 14 7
29 11 87 20 44 9 8 7 18 9 35 7 47 10 18 4 22 7 60 9 48 11 10 6 25 6
65 11 48 12 22 7 12 11 38 10 49 13 25 3 23 4 103 17 52 14
Tazarotene (3) 3 41 3 119 12 52 15 9 6 17 10 32 5 55 16 7 19 17 100
23 8 57 17 12 2 27 1 173 15 59 18 16 7 20 7 69 9 63 19 17 3 24 2
180 15 64 20 6 8 8 16 20 7 64 21 20 10 15 12 22 6 65 22 26 4 20 4
90 10 68 23 5 1 8 1 45 7 76 24 21 1 2 1 11 3 80 25 4 2 8 3 29 7 84
26 13 2 4 1 38 6 89 27 19 2 2 2 19 2 90
[0310] All publications, including but not limited to patents and
patent applications, cited in this specification are herein
incorporated by reference as if each individual publication were
specifically and individually indicated to be incorporated by
reference herein as though fully set forth.
[0311] The present invention being thus described, it will be
apparent that the same may be modified or varied in many ways. Such
modifications and variations are not to be regarded as a departure
from the spirit and scope of the present invention, and all such
modifications and variations are intended to be included within the
scope of the following claims.
* * * * *