Hair loss abstract
The present invention relates to methods of protecting against
injury to hair follicles in a mammal by administering an effective
amount of butyric acid or a biologically active butyric acid derivative.
In particular, this invention relates to the use of cell differentiation-inducing
butyric acid derivatives to protect against hair loss in cancer
patients undergoing chemotherapy and/or radiation therapy.
Hair loss claims
What is claimed is:
1. A method of protecting against injury to hair follicles in a
subject, comprising:
administering to the subject an effective amount of a compound
having the structure of: ##STR8## wherein: W.sup.1, W.sup.2 and
W.sup.3 each independent from the other represents H, F, Br, Cl
or I;
X.sup.1 and X.sup.2 each independent from the other represents
H, F, Br, Cl, I, methyl, CF.sub.3 ;
Y.sup.1 and Y.sup.2 each independent from the other represents
H, F, Br, Cl, I, methyl, CF.sub.3, ethyl or perfluoroethyl;
Z represents O; and
A represents or Q--CHR.sup.4 --O--C(.dbd.O)R.sup.5 where Q represents
a covalent bond or an alkyl; R.sup.4 represents H or an alkyl; and
R.sup.5 represents alkyl or ##STR9## a pharmaceutically acceptable
salt or prodrug thereof; and wherein said effective amount protects
the subject against hair loss.
2. The method of claim 1 in which W.sup.2, W.sup.3, X.sup.2 and
Y.sup.2 are H or F.
3. The method of claim 2 in which W.sup.1 is H or F; X.sup.1 is
H, F, methyl, CF.sub.3 and Y.sup.1 is H, F, methyl, CF.sub.3 ethyl
or perfluoroethyl.
4. The method of claim 3 in which A is alkyl or Q--CHR.sup.4 --O--C(.dbd.O)R.sup.5
where Q is a covalent bond or an alkyl; and R.sup.5 is C.sub.1 -C.sub.7
alkyl or ##STR10##
5. The method of claim 4 in which W.sup.1 is H or F X.sup.1 is
H, F, methyl, CF.sup.3 ; and Y.sup.1 is H, F, methyl, CF.sub.3,
ethyl or perfluoroethyl.
6. The method of claim 5 in which A is alkyl or Q--CHR.sup.4 --O--C(.dbd.O)R.sup.5
where Q is a covalent bond, C.sub.1 -C.sub.5 alkyl or substituted
alkyl where one or more substituents is --OC(.dbd.O)CH.sub.2 CH.sub.2
CH.sub.3, R.sup.4 is H or C.sub.1 -C.sub.5 alkyl, and R.sup.5 is
C.sub.1 -C.sub.7 alkyl or all trans
7. The method of claim 6 in which W.sup.1, W.sup.2, W.sup.3, X.sup.1,
X.sup.2, Y.sup.1 and Y.sup.2 are H.
8. The method of claim 1 in which A is Q--CHR.sup.4 --O--C(.dbd.O)R.sup.5
where Q is a covalent bond.
9. The method of claim 1 in which A is CHR.sup.4 --O--C(.dbd.O)--OR.sup.5.
10. The method of claim 1 in which the compound is pivaloyloxymethyl
butyrate.
11. The method of claim 1 in which the compound is butylidene dibutyrate.
12. The method of claim 1 in which the compound is ethylidene dibutyrate.
13. The method of claim 1 in which the compound is 2,2-dimethylpropylidene
dibutyrate.
14. The method of claim 1 in which the compound is methylidene
dibutyrate.
15. The method of claim 1 in which the compound is (butyroyloxy)methyl
octanoate.
16. The method of claim 1 in which the compound is ((2-methylpropanoyl)oxy)methyl
butyrate.
17. The method of claim 1 in which the compound is retinoyloxymethyl
butyrate.
18. The method of claim 1, wherein said subject is or has been
exposed to chemotherapy.
Hair loss description
1. INTRODUCTION
The present invention relates to methods of protecting against
injury to hair follicles in a mammal by administering an effective
amount of butyric acid or one or more of its biologically active
derivatives. In particular, this invention relates to the use of
butyric acid derivatives to protect against hair loss or damage
in human cancer patients undergoing chemotherapy and/or radiation
therapy.
2. BACKGROUND OF THE INVENTION
Alopecia (hair loss) is a common condition that results from diverse
causes. In particular, alopecia frequently occurs in cancer patients
who are treated with chemotherapeutic drugs such as cyclophosphamide
(CY) and/or irradiation. Such agents damage hair follicles which
contain mitotically active hair-producing cells. Such damage may
cause abnormally slow growth of the hair or may lead to frank loss.
While various attempts have been made to protect against alopecia
or abnormal rates of hair growth during such treatments, there remains
a need for an agent that prevents damage to hair follicles in a
safe and effective manner.
U.S. Pat. No. 5,200,553 (issued Apr. 6, 1993) describes a class
of compounds referred to as carboxylic acid esters that promote
antitumor or immune responses. These compounds are believed to be
capable of penetrating the membranes of cells and undergoing hydrolytic
cleavage intracellularly to result in butyric acid, which can induce
cell differentiation and displays antineoplastic activity.
The same class of compounds has also been shown to increase fetal
hemoglobin levels in red blood cells and thus are useful for the
treatment of .beta.-globin disorders such as sickle cell anemia
and thalassemia (WO 95/24189, published Sep. 14, 1995). In addition,
butyrate and .alpha.-amino-n-butyric acid have been used to stimulate
the expression of fetal globin gene (Perrine et al., 1993, N. Eng.
J. Med. 328:81; Perrine et al., 1989, Blood 74:454).
However, none of the aforementioned references discloses other
activities of butyric acid or butyric acid derivatives, and in particular,
the ability to protect against hair damage or loss in a mammal as
described herein.
3. SUMMARY OF THE INVENTION
The present invention relates to methods for protecting against
injury to hair follicles in a mammal by administering one or more
compounds encompassed by the following structure: ##STR1## wherein:
W.sup.1, W.sup.2 and W.sup.3 each independent from the other represents
H, F, Br, Cl, I, aryl, OR.sup.1, NR.sup.1 R.sup.2 or W.sup.1 and
W.sup.2 taken together represent a carbonyl group (.dbd.O);
X.sup.1 and X.sup.2 each independent from the other represents
H, F, Br, Cl, I, methyl, CF.sub.3, aryl, OR.sup.1, CH.sub.2 R.sup.1,
NR.sup.1 R.sup.2 or X.sup.1 and X.sup.2 taken together represent
a carbonyl group (.dbd.O);
Y.sup.1 and Y.sup.2 each independent from the other represents
H, F, Br, Cl, I, methyl, CF.sub.3, ethyl, perfluoroethyl, aryl,
OR.sup.1, CH.sub.2 OR.sup.1, CH.sub.2 CH.sub.2 OR.sup.1, CHOR.sup.1
CH.sub.3, NR.sup.1 R.sup.2 or Y.sup.1 and Y.sup.2 taken together
represent a carbonyl group (.dbd.O);
where R.sup.1 and R.sup.2 each independent from the other represents
H, C.sub.1 -C.sub.7 alkyl, aryl, arylalkyl or C(.dbd.O)CH.sub.2
CH.sub.2 CH.sub.3 ;
Z represents O or NR.sup.3 where R.sup.3 is H, alkyl, aryl or arylalkyl;
and
A represents H, alkyl, aryl, arylalkyl, carbocyclic, Q--CHR.sup.4
--O--C(.dbd.O)R.sup.5 or CHR.sup.4 --O--C(.dbd.O)--O--R.sup.5 where
Q represents a covalent bond, alkyl, or substituted alkyl where
one or more substituents is --OC(.dbd.O)R.sup.5 ;
R.sup.4 represents H, alkyl, aryl, arylalkyl; and
R.sup.5 represents alkyl, aminoalkyl, ##STR2## arylalkyl or aryl,
in which aryl by itself, and aryl in arylalkyl are each selected
from the group consisting of phenyl, naphthyl, furyl, or thienyl,
each of which is unsubstituted or substituted by at least one substituent
selected from the group consisting of alkyl, alkoxy and halogen.
The methods of the present invention also include pharmaceutically
acceptable salts and prodrugs of the aforementioned structures.
The present invention is based, in part, on Applicants' discovery
that in an animal model, while chemotherapy causes hair loss and/or
impedes hair growth, such effects are prevented or mitigated by
topical administration of butyric acid derivatives to the skin.
Therefore, a method is provided for protecting against hair loss
or impeded hair growth in an individual undergoing chemotherapy
and/or radiation therapy. In this connection, while it is possible
to utilize the compounds in vivo as raw chemicals, it is preferable
to administer them as a pharmaceutical composition which contains
butyric acid or a butyric acid derivative as an active ingredient
.
4. BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1A and 1B. Demonstration of hair removal from normal mice
(1A) by depilation (1B) on day 0 of the experiment. The back of
each animal was wax-stripped to remove the hair prior to further
treatments in order to make more visible the changes effected by
the treatments.
FIG. 2. By day 14, all mice in the control group had complete hair
regrowth. The term "Sac" refers to "sacrifice"
of certain animals for histological examination of the hair follicles.
FIG. 3. When the wax-stripped animals began to regrow their hair,
the animals in the CY group, treated with CY alone 9 days after
depilation, displayed a substantial delay in hair regrowth as compared
to untreated control animals shown in FIG. 2, indicating that CY
caused injury to hair follicles. The term "Sac" refers
to "sacrifice" of certain animals for histological examination
of the hair follicles.
FIG. 4. Animals treated with both CY and butylidene dibutyrate
showed accelerated hair regrowth as compared to those animals undergoing
CY treatment alone, indicating the ability of a butyric acid derivative
to protect against injury to hair follicles.
FIG. 5. Animals treated with both CY and pivaloyloxymethyl butyrate
also showed accelerated hair regrowth as compared to CY treatment
alone, indicating the ability of a butyric acid derivative to protect
against injury to hair follicles.
FIG. 6A-6C. Histological examination of the skin of animals on
day 14 in the control group (6A), CY-treated group (6B) and CY plus
butylidene dibutyrate-treated group (6C) confirmed the visual observations
as shown in FIGS. 2, 3 and 4. While the hair follicles (arrow) in
the skin of the control animals displayed normal morphology, the
CY-treated follicles lost the hair pigment in their center and manifested
abnormal cellular architecture. However, the hair follicles of animals
treated with CY and a butyric acid derivative more closely resemble
the normal follicles than those treated with CY alone.
5. DETAILED DESCRIPTION OF THE INVENTION
The present invention relates to methods of using butyric acid
or butyric acid derivatives to protect against injury to hair follicles.
The invention is discussed in more detail in the subsections below,
solely for the purpose of description and not by way of limitation.
For clarity of discussion, the specific procedures and methods described
herein are exemplified using a murine model. These procedures and
methods are merely illustrative for the practice of the invention.
Analogous procedures and techniques, as well as other compounds,
are equally applicable to mammals, including humans.
5.1 Butyric Acid and its Derivatives
The present invention provides a method for protecting against
injury to hair follicles as manifested by hair loss or slow rates
of hair regrowth in a subject in need of chemotherapy and/or radiation
treatment by administering one or more compounds encompassed by
the structure of: ##STR3## wherein:
W.sup.1, W.sup.2 and W.sup.3 each independent from the other represents
H, F, Br, Cl, I, aryl, OR.sup.1, NR.sup.1 R.sup.2 or W.sup.1 and
W.sup.2 taken together represent a carbonyl group (.dbd.O);
X.sup.1 and X.sup.2 each independent from the other represents
H, F, Br, Cl, I, methyl, CF.sub.3, aryl, OR.sup.1, CH.sub.2 OR.sup.1,
NR.sup.1 R.sup.2 or X.sup.1 and X.sup.2 taken together represent
a carbonyl group (.dbd.O);
Y.sup.1 and Y.sup.2 each independent from the other represents
H, F, Br, Cl, I, methyl, CF.sub.3, ethyl, perfluoroethyl, aryl,
OR.sup.1, CH.sub.2 OR.sup.1, CH.sub.2 CH.sub.2 OR.sup.1, CHOR.sup.1
CH.sub.3, NR.sup.1 R.sup.2 or Y.sup.1 and Y.sup.2 taken together
represent a carbonyl group (.dbd.O);
where R.sup.1 and R.sup.2 each independent from the other represents
H, C.sub.1 -C.sub.7 alkyl, aryl, arylalkyl or C(.dbd.O)CH.sub.2
CH.sub.2 CH.sub.3 ;
Z represents O or NR.sup.3 where R.sup.3 is H, alkyl, aryl, arylalkyl;
and
A represents H, alkyl, aryl, arylalkyl, carbocyclic, Q--CHR.sup.4
--O--C(.dbd.O)R.sup.5 or CHR.sup.4 --O--C(.dbd.O)--O--R.sup.5 where
Q represents a covalent bond, alkyl, or substituted alkyl where
one or more substituents is --OC(.dbd.O)R.sup.5 ;
R.sup.4 represents H, alkyl, aryl, arylalkyl; and
R.sup.5 represents alkyl, aminoalkyl, ##STR4## arylalkyl or aryl,
in which aryl by itself, and aryl in arylalkyl are each selected
from the group consisting of phenyl, naphthyl, furyl, or thienyl,
each of which is unsubstituted or substituted by at least one substituent
selected from the group consisting of alkyl, alkoxy and halogen.
The methods of the invention also include pharmaceutically acceptable
salts and prodrugs of butyric acid and butyric acid derivatives
encompassed by the above structure.
For the compounds encompassed by the methods of the invention and
for the pharmaceutical compositions which contain such compounds,
it is preferred that alkyl radicals, including those which form
part of alkoxy and arylalkyl radicals contain no more than about
30 carbon atoms.
A preferred method of the present invention comprises the administration
of a compound encompassed by the aforementioned structure wherein
W.sup.1 is H, F, OR.sup.1, phenyl, substituted phenyl or NR.sup.1
R.sup.2 ; X.sup.1 is H, F, OR.sup.1, methyl, CF.sub.3, CH.sub.2
OR.sup.1, phenyl, substituted phenyl or NR.sup.1 R.sup.2 ; Y.sup.1
is H, F, OR.sup.1, methyl, CF.sub.3, CH.sub.2 OR.sup.1, phenyl,
substituted phenyl, ethyl, perfluoroethyl, CH.sub.2 CH.sub.2 OR.sup.1,
CHOR.sup.1 CH.sub.3 or NR.sup.1 R.sup.2 ; W.sup.2, W.sup.3, X.sup.2
and Y.sup.2 are H or F; where R.sup.1 and R.sup.2 are H, C.sub.1
-C.sub.5 alkyl, phenyl, substituted phenyl or C(.dbd.O)CH.sub.2
CH.sub.2 CH.sub.3 ; Z is O or NR.sup.3 where R.sup.3 is H, alkyl,
aryl, arylalkyl; and A is H, alkyl, aryl, arylalkyl, carbocyclic,
Q--CHR.sup.4 --O--C(.dbd.O)R.sup.5 or CHR.sup.4 --O--C(.dbd.O)--OR.sup.5
where Q is a covalent bond, alkyl or substituted alkyl where one
or more substituents is --OC(.dbd.O)CH.sub.2 CH.sub.2 CH.sub.3.
R.sup.4 represents H, alkyl, aryl, arylalkyl and R.sup.5 represents
C.sub.1 -C.sub.7 alkyl, ##STR5## arylalkyl or aryl, in which aryl
by itself, and aryl in arylalkyl are each selected from the group
consisting of phenyl, naphthyl, furyl, or thienyl, each of which
is unsubstituted or substituted by at least one substituent selected
from the group consisting of alkyl, alkoxy and halogen.
Specifically preferred is the method which comprises the administration
of a compound encompassed by the aforementioned structure wherein
W.sup.1 is H, F, phenyl, NH.sub.2, OR.sup.1 ; X.sup.1 is H, F, methyl,
CF.sub.3, OR.sup.1, CH.sub.2 OR.sup.1, phenyl or NH.sub.2 ; Y.sup.1
is H, F, methyl, CF.sub.3, OR.sup.1, CH.sub.2 OR.sup.1, ethyl, perfluoroethyl,
phenyl, CH.sub.2 CH.sub.2 OR.sup.1, CHOR.sup.1 CH.sub.3 or NH.sub.2
where R.sup.1 is H, C.sub.1 -C.sub.5 alkyl or C(.dbd.O)CH.sub.2
CH.sub.2 CH.sub.3 ; W.sup.2, W.sup.3, X.sup.2 and Y.sup.2 are H
or F; Z is O or NH; and A is H, alkyl, aryl, arylalkyl, carbocyclic,
Q--CHR.sup.4 --O--C(.dbd.O)R.sup.5 or CHR.sup.4 --O--C(.dbd.O)--O--R.sup.5
where Q is a covalent bond, alkyl or substituted alkyl where one
or more substituents is --OC(.dbd.O)CH.sub.2 CH.sub.2 CH.sub.3 ;
R.sup.4 is H, C.sub.1 -C.sub.7 alkyl; and Rs is C.sub.1 -C.sub.7
alkyl or ##STR6##
More specifically preferred is the method which comprises the administration
of a compound encompassed by the aforementioned structure wherein
W.sup.1, W.sup.2, W.sup.3, X.sup.1, X.sup.2, Y.sup.1 and Y.sup.2
are H; Z is O or NH; and A is H, alkyl, aryl, arylalkyl, carbocyclic,
Q--CHR.sup.4 --O--C(.dbd.O)R.sup.5 or CHR.sup.4 --O--C(.dbd.O)--O--R.sup.5
where Q is a covalent bond, C.sub.1 -C.sub.5 alkyl or substituted
C.sub.1 -C.sub.5 alkyl where one or more substituents is --OC(.dbd.O)CH.sub.2
CH.sub.2 CH.sub.3 ; R.sup.4 is H or C.sub.1 -C.sub.5 alkyl; and
R.sup.5 is C.sub.1 -C.sub.7 alkyl or all trans ##STR7##
Examples of such a compound include, but are not limited to, butyric
acid, butyrate salts, butyramides, butyric acid esters and isomers
thereof. In particular, a butyric acid ester is selected from the
group consisting of butylidene dibutyrate; pivaloyloxymethyl butyrate;
ethylidene dibutyrate; (1-butyroyloxy)ethyl ethyl carbonate; 2,2-dimethylpropylidene
dibutyrate; 3-(butyroyloxy)phthalide; (butyroyloxy)methyl octanoate;
methylidene dibutyrate; ((2-methylpropanoyl)oxy)methyl butyrate;
tocopheryl butyrate; glyceryl tributyrate; and retinoyloxymethyl
butyrate.
The compounds suitable for use in the methods herein described
may have asymmetric centers. All chiral, diastereomeric, and racemic
forms are included in the present invention. Many geometric isomers
of olefins and the like can also be present in the compounds described
herein, and all such stable isomers are encompassed in the present
invention.
When any variable (for example, R.sup.1, R.sup.2, R.sup.3, R.sup.4
and R.sup.5 etc.) occurs more than one time in any constituent or
in the structure described above or any other formula herein, its
definition on each occurrence is independent of its definition at
every other occurrence. Also, combinations of substituents and/or
variables are permissible only if such combinations result in stable
compounds.
For the purpose of this application, "alkyl" is intended
to include both branched-, straight- or cyclic-saturated aliphatic
hydrocarbon groups having the specified number of carbon atoms;
e.g. methyl, ethyl, propyl, isopropyl, butyl, isobutyl, secondary
butyl, tertiary butyl, hexyl, cyclohexyl, heptyl, octyl, decyl,
dodecyl or octadecyl. As used herein and in the claims, "aryl"
or "aromatic residue" is intended to mean phenyl, furyl,
thienyl or naphthyl; "carbocyclic" is intended to mean
any stable 5- to 7- membered monocyclic or bicyclic or 7- to 14-membered
bicyclic or tricyclic carbon ring, any of which may be saturated,
partially unsaturated, or aromatic, for example, indanyl or tetrahydronaphthyl
(tetralin). Aryl radicals, including those which form part of arylalkyl,
aryloxy and aralkoxy radicals, may be substituted or not, and may
be carbocyclic; substituents when present may be selected from,
e.g. alkyl, alkoxy and halogen. The term "alkoxy", as
used herein and in the claims, represents an alkyl group of indicated
number of carbon atoms attached through an oxygen bridge.
The term "substituted", as used herein and in the claims,
means that one or more hydrogens on the designated atom is replaced
with a selection from the indicated group, provided that the designated
atom's normal valency is not exceeded, and that the substitution
results in a stable compound. By "stable compound" or
"stable structure" is meant herein a compound that is
sufficiently robust to survive isolation to a useful degree of purity
from a reaction mixture, and formulation into an efficacious therapeutic
agent.
As used herein and in the claims, "therapeutically effective
amount" refers to that amount necessary to administer to a
host to achieve the desired result of protection against injury
to hair follicles.
As used herein and in the claims, "pharmaceutically acceptable
salts and prodrugs" refer to derivatives of the disclosed compounds
that are modified by making acid or base salts, or by modifying
functional groups present in the compounds in such a way that the
modifications are cleaved, either in routine manipulation or in
vivo in relation to the parent compounds. Examples include, but
are not limited to, mineral or organic acid salts of basic residues
such as amines; alkali or organic salts of acidic residues such
as carboxylic acids; acetate, formate and benzoate derivatives of
alcohols and amines; and the like.
Pharmaceutically acceptable salts of the compounds of the invention
can be prepared by reacting the free acid or base forms of these
compounds with a stoichiometric amount of the appropriate base or
acid in water or in an organic solvent, or in a mixture of the two;
generally, nonaqueous media like ether, ethyl acetate, ethanol,
isopropanol, or acetonitrile are preferred. Lists of suitable salts
are found in Remington's Pharmaceutical Sciences, 17th ed., Mack
Publishing Company, Easton, Pa., 1985, p. 1418, the disclosure of
which is hereby incorporated by reference in its entirety.
5.2 Preparation of Butyric Acid Derivatives
The compounds of the present invention may be prepared generally
by any method known in the art. For the formation of an ester group
or a carbonate group, the method described in U.S. Pat. No. 5,200,533
may be used.
For example, compounds wherein R.sup.5 is other than propyl may
be prepared by reacting butyric acid with a reagent of formula Y--CHR.sup.4
--O--(O.dbd.)C--R.sup.5 in the presence of a base, where Y is leaving
group such as halogen, methanesulfonate or P-toluenesulfonate, and
R.sup.4 and R.sup.5 are as previously defined. The base may be,
e.g., a trialkylamine, pyridine or an alkali metal carbonate. The
reaction may be carried out in the absence or presence of an inert
solvent. When a solvent is used, this may be, for example, acetone,
ether, benzene, toluene, tetrahydrofuran, ethyl acetate, acetonitrile,
dimethylformamide, dimethyl sulfoxide, chloroform, dioxane or 1,2-dichloroethane.
When R.sup.5 is propyl, the compounds may be prepared by an alternate
process by reacting butyric anhydride with an aldehyde of the formula
(R.sup.4 --CHO), wherein R.sup.4 is as defined above, in the presence
of an acid catalyst such as boron trichloride, aluminum trichloride,
tin dichloride, sulfuric acid, phosphoric acid or zinc chloride.
Several compounds suitable for use in the present invention are
illustrated by the following non-limiting examples:
5.2.1 Butylidene Dibutyrate
To ice-cooled BF.sub.3 -etherate (8.66 g., 61 mmol.) is added dropwise
via a syringe, over one hour, a mixture of butyric anhydride (6.58
g., 41.6 mmol.) and butyraldehyde (1.22 g., 27.7 mmol.). The reaction
mixture is stirred for an additional 2 hours, 10% aq. sodium acetate
solution (28 ml.) is added, and the mixture again stirred for 45
minutes. The oily layer is extracted into ether (2.times.25 ml.),
and the combined ethereal extracts are washed with saturated aqueous
sodium bicarbonate solution until no further evolution of CO.sub.2
is observed. The organic phase is then washed with water, dried
over magnesium sulfate, filtered, concentrated and the residue is
fractionally distilled at 8-12 mm. .sup.1 H-NMR ppm (CDCl.sub.3):
6.82 (t, J=5.6 Hz, 1H), 2.30 (m, 4H), 1.75 (m, 2H). 1.65 (sextet,
J=7.5 Hz, 4H), 1.40 (q, J=7.5 Hz, 2H). 0.953 and 0.949 (2t, J=7.5
Hz, 9H).
5.2.2 Pivaloyloxymethyl Butyrate
To a mixture of butyric acid (5.7 ml., 40 mmol.) and chloromethyl
pivalate (18 ml., 1 mmol.) in acetone (10 ml.) is added triethylamine
(12.17 ml., 88 mmol.). The reaction mixture is stirred at room temperature
for 24 hours, it is then evaporated and the residue is treated with
a mixture of water and ethyl acetate. The organic phase is separated,
dried over potassium carbonate, filtered and evaporated. The residue
is fractionally distilled, to give the title compound (4.42 g.,
yield 57%). b.p. 88.degree.-93.degree. C./2 mm. .sup.1 H-NMR ppm
(CDCl.sub.3): 5.753 (s, 2H). 2.336 (t, 2H), 1.670 (sextet, 2H),
1.213 (s. 9H). 0.953 (t, 3H).
5.2.3 Ethylidene Dibutyrate
.sup.1 H H-NMR ppm (CDCl.sub.3); 6.88 (q. J=5.6 Hz, 1H), 2.30 dt,
J=0.75, 7.5 Hz, 4H), 1.65 (sextet, J=7.5 Hz. 4H). 1.47 (d. J=5.5
Hz, 3H). 0.95 (t, J=7.5 Hz, 6H).
5.2.4 (1-Butyroyloxy)Ethyl Ethyl Carbonate
.sup.1 H-NMR ppm (CDCl.sub.3): 6.77 (q. J=5 Hz, 1H), 4.22 (q. J=7
Hz, 2H), 2.32 (t, J=7.5 Hz, 2H), 1.66 (sextet, J=7.5 Hz, 2H), 1.52
(d, J=5.5 Hz, 3H), 1.318 (t, J=7.5 Hz, 3H), 0.95 (t, J=7.5 Hz, 3H).
5.2.5 2,2-Dimethylpropylidene Dibutyrate
.sup.1 H-NMR ppm (CDCl.sub.3): 6.59 (s, 1H), 2.31 (t, 4H), 2.20
(sextet, 4H), 1.50 (s, 9H), 1.49 (t, 6H).
5.2.6 Octanoyloxymethyl Butyrate
.sup.1 H-NMR ppm (CDCl.sub.3): 5.70 (s, 2H), 2.38-2.11 (m, 4H),
1.7-1.6 (m, 4H), 1.3-1.1 (m, 8H), 0.92 (t, 3H), 0.87 (t, 3H).
5.2.7 3-(Butyroyloxy)Phthalide
.sup.1 H-NMR ppm (CDCl.sub.3): 7.93 (dd, J=0.7, 7.5 Hz, 1H), 7.76
(dt, J=1.1, 7.5 Hz, 1H), 7.65 (dt, J=1.0, 8.2 Hz, 1H), 7.58 (dd,
J=0.7, 8.2 Hz, 1H), 7.46 (s, 1H), 2.42 (t, J=7.4, Hz, 2H), 1.72
(sextet, J=7.4, Hz, 2H), 0.99 (t, J=7.4, Hz, 3H).
5.2.8 Iso-Butyroyloxymethyl Butyrate
.sup.1 H-NMR ppm (CDCl.sub.3): 5.77 (s, 2H), 2.60 (septet, 1H),
2.36 (t, 2H), 1.69 (sextet, 2H), 1.19 (d, 6H), 0.96 (t,3H).
The procedures outlined above can be improved by one skilled in
the art by, for instance, changing the temperature or stoichiometry
of the reactions. Any such changes are intended to fall within the
scope of this invention.
5.3 Dosage and Formulation
The compounds described in Sections 5.1 and 5.2 supra, may be administered
for the protection against injury to hair follicles by any means
that produces contact of the active agent with the agent's site
of action in the body of a mammal. They can be administered by any
conventional means available for use in conjunction with pharmaceuticals,
either as individual therapeutic agents or in a combination of therapeutic
agents. Each can be administered alone but is generally administered
with a pharmaceutical carrier selected on the basis of the chosen
route of administration and standard pharmaceutical practice. The
pharmaceutical compositions of the invention may be adapted for
oral, parenteral, topical or rectal administration, and may be in
unit dosage form, in a manner well known to those skilled in the
pharmaceutical art. Parenteral administration includes but is not
limited to, injection subcutaneously, intravenously, intraperitoneally
or intramuscularly.
With respect to the timing of an injury to the hair follicle by
chemotherapy and/or radiation therapy, treatment with the active
ingredient may begin before, during or after the injurious event
has occurred, with the preferred timing being from 3 to 7 days before
chemotherapy and/or radiation therapy and continuing until 3 to
7 days after chemotherapy and/or radiation therapy has been completed.
The dose administered will, of course, vary depending upon known
factors, such as: the pharmacodynamic characteristics of the particular
agent and its mode and route of administration; the age, health,
height and weight of the recipient; the nature and extent of the
symptoms; the kind of concurrent treatment(s); the frequency of
treatment(s); and the effect desired. A daily dose of active ingredient
can be expected to be about 0.05 to 50 grams per kilogram of body
weight, with the preferred dose being 1 to 10 grams per kilogram
of body weight. When the active ingredient is administered topically
to the skin (such as the scalp), the daily dose of active ingredient
can be expected to be about 0.1 to 200 milligrams per square centimeter
of surface area, with the preferred dose being 3.22 to 32.2 milligrams
per square centimeter of surface area.
Dosage forms (compositions suitable for administration) contain
from about 1 milligram to about 500 milligrams of active ingredient
per unit. In these pharmaceutical compositions, the active ingredient
is ordinarily present in an amount of about 0.5-95% by weight based
on the total weight of the composition.
The active ingredient can be administered orally in solid or semi-solid
dosage forms, such as hard or soft-gelatin capsules, tablets, or
powders, or in liquid dosage forms, such as elixirs, syrups, or
suspensions. It can also be administered parenterally, in sterile
liquid dosage forms. Other dosage forms are potentially possible
such as patches or ointment or transdermal administration.
Gelatin capsules or liquid-filled soft gelatin capsules may contain
the active ingredient and powdered or liquid carriers, such as lactose,
lecithin starch, cellulose derivatives, magnesium stearate, stearic
acid, and the like. Similar diluents can be used to make compressed
tablets. Both tablets and capsules can be manufactured as sustained
release products to provide for continuous release of medication
over a period of hours. Compressed tablets can be sugar-coated or
film-coated to mask any unpleasant taste and to protect the tablet
from the atmosphere, or enteric-coated for selective disintegration
in the gastrointestinal tract. Liquid dosage forms for oral administration
can contain coloring and/or flavoring to increase patient acceptance.
In general, water, oil, saline, aqueous dextrose (glucose), polysorbate
and related sugar solutions and glycols such as propylene glycol
or polyethylene glycols are suitable carriers for parenteral solutions.
Solutions or emulsions for parenteral administration preferably
contain about 5-15% polysorbate 80 or lecithin, suitable stabilizing
agents, and if necessary, buffer substances. Antioxidizing agents,
such as but not limited to, sodium bisulfite, sodium sulfite, or
ascorbic acid, either alone or combined, are suitable stabilizing
agents. Also used are citric acid and its salts and sodium EDTA.
In addition, parenteral solutions can contain preservatives, including
but not limited to, benzalkonium chloride, methyl- or propyl-paraben,
and chlorobutanol.
Suitable pharmaceutical carriers are further described in Remington's
Pharmaceutical Sciences, 17th ed., Mack Publishing Company, Easton,
Pa. (1990) a standard reference text in this field, which is incorporated
herein by reference in its entirety.
Useful pharmaceutical dosage forms for administration of the compounds
of this invention can be illustrated as follows:
5.3.1 Topical Formulation
For topical administration, butyric acid or butyric acid derivatives
may be formulated as a solution, gel, lotion, ointment, cream, suspension,
paste, liniment, powder, tincture, aerosol, transdermal drug delivery
system, and the like in a pharmaceutically acceptable form by methods
well known in the art. Actual methods for preparing topical formulations
are known or apparent to those skilled in the art, and are described
in detail in Remington's Pharmaceutical Sciences, 17th ed., Mack
Publishing Company, Easton, Pa. (1990); and Pharmaceutical Dosage
Forms and Drug Delivery Systems, 6th ed., Williams & Wilkins
(1995).
In order to enhance the percutaneous absorption of the active ingredients,
a number of agents may be added in the topical formulations, including,
but not limited to, dimethylsulfoxide, dimethylacetamide, dimethylformamide,
surfactants, azone, alcohol, acetone, propylene glycol and polyethylene
glycol. In addition, physical methods may also be used to enhance
transdermal penetration such as iontophoresis or sonophoresis.
The pharmaceutical compositions may be applied directly to the
skin, such as the scalp. Alternatively, they may be delivered by
various transdermal drug delivery systems, such as patches.
5.3.2 Capsules
A large number of unit capsules are prepared by filling standard
two-piece hard gelatin capsules with the active ingredient and inactive
ingredients such as lactose, cellulose and magnesium stearate. For
example, a two-piece hard gelatin capsule may be filled with 10-500
milligrams of powdered active ingredient, 150 milligrams of lactose,
50 milligrams of cellulose, and 6 milligrams magnesium stearate.
5.3.3 Soft Gelatin Capsules
A mixture of active ingredients in ea digestible oil such as soybean
oil, lecithin, cottonseed oil or olive oil is prepared and injected
by means of a positive displacement pump into gelatin to form soft
gelatin capsules containing 10-500 milligrams of the active ingredient.
The capsules are washed and dried.
5.3.4 Tablets
A large number of tablets are prepared by conventional procedures
to contain the active ingredient and inactive ingredients such as
colloidal silicon dioxide, magnesium stearate, microcrystalline
cellulose, starch and lactose. A tablet may be prepared so that
the dosage unit is 10-500 milligrams of active ingredient, 0.2 milligrams
of colloidal silicon dioxide, 5 milligrams of magnesium stearate,
275 milligrams of microcrystalline cellulose, 11 milligrams of starch
and 98.8 milligrams of lactose. Appropriate coatings may be applied
to increase palatability or delay absorption.
6. EXAMPLE: BUTYRIC ACID DERIVATIVES PROTECT AGAINST CHEMOTHERAPY-INDUCED
INJURY TO HAIR FOLLICLES
Certain butyric acid derivatives have been proposed as anti-cancer
agents based on their ability to induce terminal differentiation
of tumor cells. In order to determine whether such cell differentiation-inducing
agents can induce maturation of non-malignant cells to result in
a therapeutical effect, butylidene dibutyrate (see Section 5.2.1)
and pivaloyloxymethyl butyrate (see Section 5.2.2) were tested in
an animal model for their ability to protect against chemotherapy-induced
injury to hair follicles.
6.1 Materials and Methods
6.1.1 Reagents
CY was manufactured by ASTA Medica AG, and purchased from Pharmacia
Incorporated (Columbus, Ohio) labeled as "NEOSAR."
Butyric acid derivatives were prepared according to the methods
disclosed in U.S. Pat. No. 5,200,553. In brief, butylidene dibutyrate
was synthesized by reacting the anhydride of butyric acid with butyraldehyde
in the presence of borontrifluoride diethyletherate, followed by
washing and distillation to achieve purification. Pivaloyloxymethyl
butyrate was synthesized by reacting butyric acid with chloromethylpivalate
in the presence of triethylamine, followed by washing and distillation
to achieve purification.
6.1.2 Animal Model
Normal C57BL6 mice were used for all experiments. In order to enhance
the visibility of changes effected by treatment, wax depilation
was performed on the back of each animal on day 0 (Paus et al.,
1994, Am. J. Pathol. 144:719-734). A sufficient quantity of "surgi-wax"
(manufactured by Ardell and purchased over the counter) was placed
in a glass beaker and melted in a microwave. It was allowed to cool
for a few minutes and applied over approximately 6 cm.sup.2 of the
dorsal fur of a mouse from the neck to behind the shoulders using
a wooden applicator. The wax was allowed to harden for approximately
two minutes, and then gently removed manually under traction, which
also removed the entrapped hair. The process was repeated 2 to 3
times in order to produce a smooth, depilated area of relatively
uniform size and shape (FIG. 1A and 1B).
The animals were then divided into different groups. A control
group of animals received no further treatment. A separate group
received a single dose of CY at 100 mg/kg of body weight intraperitoneally
(i.p.) on day 9. A third group of animals received CY as described
above and also received butylidene dibutyrate (about 950 mg/ml)
topically at the site of hair depilation each day from day 6 to
day 11. In the case of butylidene dibutyrate, 0.2 ml was administered
three times per day on day 6 followed by 0.1 ml once a day from
day 7 to 11. A fourth group of animals received CY as described
above but also received pivaloyloxymethyl butyrate (about 970 mg/ml)
topically at the site of hair depilation per day from day 6 to day
11. For pivaloyloxymethyl butyrate, 0.1 ml was administered once
a day from day 6 to 11. Hair growth in all groups was monitored
on days 7, 9, 14, 16, 20, 23, 27, 30 and 34. Hair growth was examined
visually and histologically up to day 34.
6.2 Results
Hair regrowth in the control animals occurred rapidly and fully
within 14 days of the pretreatment depilation (FIG. 2). When animals
received a single dose of CY (100 mg/kg i.p.) nine days after depilation,
hair growth was retarded for more than two weeks, such that complete
regrowth was not achieved in the majority of the animals until day
30-34 (FIG. 3). However, when the CY-treated animals also received
butylidene dibutyrate topically, hair regrowth was significantly
accelerated as compared to the mice exposed to CY alone (FIG. 4).
Similarly, animals treated with pivaloyloxymethyl butyrate topically
in combination with CY also exhibited accelerated regrowth of hair
as compared to CY alone, although to a lesser degree than that achieved
with butylidene dibutyrate treatment (FIG. 5). Histological examination
of the follicles on day 14 confirmed the visual observations (FIG.
6A-6C).
These results show that administration of butyric acid derivatives
protected animals against CY-induced injury to hair follicles, as
evidenced by accelerated hair regrowth. Therefore, these compounds
are particularly useful in protecting against injury to the hair
follicles which results from certain clinical procedures, such as
anesthesia, cancer chemotherapy or radiation therapy.
The present invention is not to be limited in scope by the exemplified
embodiments, which are intended as illustrations of the invention.
Indeed, various modifications of the invention in addition to those
shown and described herein will become apparent to those skilled
in the art from the foregoing description and accompanying drawings.
Such modifications are also intended to fall within the scope of
the appended claims.
The foregoing disclosure includes all the information deemed essential
to enable those skilled in the art to practice the claimed invention.
All publications cited herein are incorporated by reference in their
entirety.
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