U.S. patent number 5,039,705 [Application Number 07/409,552] was granted by the patent office on 1991-08-13 for anti-hypertensive compositions of secondary amine-nitric oxide adducts and use thereof.
This patent grant is currently assigned to The United States of America as represented by the Department of Health. Invention is credited to Tambra M. Dunams, Joseph A. Hrabie, Larry K. Keefer, David A. Wink.
United States Patent |
5,039,705 |
Keefer , et al. |
August 13, 1991 |
Anti-hypertensive compositions of secondary amine-nitric oxide
adducts and use thereof
Abstract
This invention concerns anti-hypertensive compositions and a
method of lowering blood pressure in mammals. The active component
of the compositions is a compound of the formula: ##STR1## wherein
R.sub.1 and R.sub.2 are independently chosen from straight chain
and branched chain C.sub.1 -C.sub.12 alkyl groups and benzyl, with
the proviso that no branch occur on the alpha carbon atom of the
alkyl groups; or R.sub.1 and R.sub.2 together with the nitrogen
atom they are bonded to form a pyrrolidino, piperidino, piperazino
or morpholino group, M.sup.+ is a pharmaceutically acceptable
cation, wherein X is the valence of the cation.
Inventors: |
Keefer; Larry K. (Bethesda,
MD), Wink; David A. (Frederick, MD), Dunams; Tambra
M. (Frederick, MD), Hrabie; Joseph A. (Frederick,
MD) |
Assignee: |
The United States of America as
represented by the Department of Health (Washington,
DC)
|
Family
ID: |
23620991 |
Appl.
No.: |
07/409,552 |
Filed: |
September 15, 1989 |
Current U.S.
Class: |
514/611; 514/558;
514/579; 514/645; 514/563; 514/564; 514/610; 514/149 |
Current CPC
Class: |
A61K
31/135 (20130101); A61K 31/13 (20130101); A61P
35/00 (20180101); C07C 291/08 (20130101); C07D
295/30 (20130101); A61K 31/40 (20130101); A61K
31/445 (20130101); A61K 31/495 (20130101); A61P
9/12 (20180101); A61K 31/535 (20130101); C07C
307/02 (20130101) |
Current International
Class: |
A61K
31/495 (20060101); A61K 31/535 (20060101); C07C
307/00 (20060101); A61K 31/135 (20060101); C07C
307/02 (20060101); A61K 31/13 (20060101); C07C
291/00 (20060101); C07C 291/08 (20060101); C07D
295/28 (20060101); A61K 31/445 (20060101); A61K
31/40 (20060101); C07D 295/00 (20060101); A61K
031/13 (); A61K 031/20 (); A61K 031/195 (); A61K
031/655 () |
Field of
Search: |
;514/611,149,558,563,564,610,645,579 |
References Cited
[Referenced By]
U.S. Patent Documents
Other References
Palmer, Nature 327, 524-526, 1987. .
Kruszyna et al. Toxicol. and Applied Pharmacol. 91, 429-438, 1987.
.
Ignarro, The FASEB Journal 3, 31-36, 1989. .
Ignarro et al., J. Pharmacol. & Exper. Therapeutics 218(2),
739-749, 1981. .
Drago, "Free Radicals in Inorganic Chemistry", No. 36, Advances in
Chemistry Series, Amer. Chem. Soc., Wash. DC, 1962, pp. 143-149.
.
Drago et al., J. Amer. Chem. Soc. 83, 1819-1822, 1961. .
Deluca et al., "Pharmaceutics and Pharmacy Practice" J.B.
Lippincott Co., Philadelphia, 1982, 238-250. .
Trissel, ASHP, "Handbook on Injectable Drugs" 4th ed; 622-630,
1986..
|
Primary Examiner: Robinson; Allen J.
Attorney, Agent or Firm: Bailey; John Benson; Robert
Claims
What is claimed is:
1. A sterile pharmaceutical composition useful in the treatment of
hypertension comprising: an effective amount of a compound of the
formula ##STR5## wherein R.sub.1 and R.sub.2 are independently
selected from the group consisting of a straight chain or branched
chain C.sub.1 -C.sub.12 alkyl group and a benzyl group, with the
proviso that no branch occur on the alpha carbon atom, M.sup.+X is
a pharmaceutically acceptable cation, wherein x is the valence of
the cation; and a pharmaceutically acceptable carrier therefor.
2. The composition of claim 1 in a form suitable for injection.
3. The composition of claim 2 wherein R.sub.1 and R.sub.2 are
independently selected from the group consisting of C.sub.2
-C.sub.6 alkyl groups.
4. The composition of claim 3 wherein M.sup.+X is selected from the
group consisting of group I, group II ions and NR.sub.3 R.sub.4
R.sub.5 R.sub.6.sup.+, wherein R.sub.3, R.sub.4, R.sub.5 and
R.sub.6 are independently selected from the group consisting of H,
C.sub.1 -C.sub.12 alkyl, C.sub.3 -C.sub.7 cycloalkyl and benzy.
5. The composition of claim 4 wherein R.sub.1 and R.sub.2 are
ethyl.
6. The composition of claim 5 wherein M.sup.+X is Na.sup.+,
K.sup.+, Ca.sup.+2 or N(C.sub.2 H.sub.5).sub.2 H.sub.2.sup.+.
7. The composition of claim 2, 3, 4, 5 or 6 wherein the
pharmaceutically acceptable carrier is selected from the group
consisting of sterile water, phosphate buffered saline and aqueous
glucose solutions.
8. The pharmaceutical composition of claim 1, wherein said
composition is a sterile composition suitable for intravenous
injection.
9. The pharmaceutical composition of claim 8, wherein said
composition further comprises an antioxidant.
10. A method of treating hypertension in mammals which comprises
administering to a mammal, in need thereof, a blood pressure
lowering effective amount of a compound of the formula: ##STR6##
wherein R.sub.1 and R.sub.2 are independently selected from the
group consisting of a straight chain or branched chain C.sub.1
-C.sub.12 alkyl group and a benzyl group, with the proviso that no
branch occur on the alpha carbon atom; and M.sup.+X is a
pharmaceutically acceptable cation, wherein x is the valence of the
cation.
11. The method of claim 16 wherein R.sub.1 and R.sub.2 are
independently selected from C.sub.2 -C.sub.6 alkyl groups.
12. The method of claim 11 wherein M.sup.+X is selected from the
group consisting of group I, group II ions and NR.sub.3 R.sub.4
R.sub.5 R.sub.6.sup.+, wherein R.sub.3, R.sub.4, R.sub.5 and
R.sub.6 are independently selected from H, C.sub.1 -C.sub.12 alkyl
groups, C.sub.3 -C.sub.7 cycloalkyl or benzyl.
13. The method of claim 12 wherein R.sub.1 and R.sub.2 are
ethyl.
14. The method of claim 13 wherein M.sup.+X is NA.sup.+, K.sup.+,
Ca.sup.+2 or N(C.sub.2 H.sub.5).sub.2 H.sub.2.sup.+.
Description
INTRODUCTION
This invention concerns novel pharmaceutical compositions and a
method of treating hypertension. Related compositions and methods
are described in U.S. Pat. application SN No. 07/316,958, filed
Feb. 28, 1989, now U.S. Pat. No. 4,954,526, and in SN 07/423,279,
filed on Nov. 18, 1989.
BACKGROUND OF THE INVENTION
Endothelium-derived relaxing factor (EDRF) is a labile humoral
agent which is part of a cascade of interacting agents involved in
the relaxation of vascular smooth muscle. EDRF is thus important in
the control of vascular resistance to blood flow and in the control
of blood pressure. Some vasodilators act by causing EDRF to be
released from endothelial cells. (See Furchgott,
Ann.Rev.Pharmacol.Toxicol. 24, 175-197, 1984.) Recently, Palmer et
al., have shown that EDRF is identical to the simple molecule,
nitric oxide, NO. (Nature 317, 524-526, 1987.) It has been
hypothesized for years that many nitrovasodilators that mimic the
effect of EDRF, like glyceryl trinitrate, amyl nitrite, NaNO.sub.2
and sodium nitroprusside (SNP), do so by virtue of their conversion
to a common moiety, namely NO, which is also a vasodilator. (See
Kruszyna et al., Tox.& Appl. Pharmacol., 91, 429-438, 1987;
Ignarro, FASEB J. 3, 31-36, 1989 and Ignarro et al., J. Pharmacol.
Exper. Theraputics 218(3), 739-749, 1981.) It has now been
discovered that a class of compounds of the structure: ##STR2##
wherein A is a secondary amino group, are potent antihypertensives
and thus are useful for treating cardiovascular disorders in which
lowering the blood pressure has a beneficial result. It is believed
that these compounds function by releasing NO in the blood after
injection; however the invention should not be limited by this
hypothesis. While these compounds are, for the most part, known,
there is no suggestion in the prior art that they are
anti-hypertensive, indeed, there is no suggestion in the prior art
that these compounds have any pharmaceutical use. They are
described by Drago in "Free Radicals in Inorganic Chemistry",
Number 36, Advances in Chemistry Series, American Chemical Society,
Wash. DC, 1962, pages 143-149 and Drago et al. J. Amer. Chem. Soc.
83, 1819-1822, 1961. These two articles by Drago are incorporated
by reference, in their entirety. The references are of a
theoretical nature and mention no utility whatsoever. Reilly, U.S.
Pat. No. 3,153,094, discloses these compounds on columns 11-13, but
does not teach any biological activity.
DESCRIPTION OF THE INVENTION
The present invention provides pharmaceutical compositions
comprising: a compound of the following formula ##STR3## wherein
R.sub.1 and R.sub.2 are independently chosen from straight chain
and branched chain alkyl groups of one to twelve carbon atoms or
benzyl, with the proviso that no branch occur on the alpha carbon
of the alkyl groups, or R.sub.1 and R.sub.2 together with the
nitrogen atom they are bonded to form a pyrrolidino, piperidino,
piperazino or morpholino ring, M.sup.+X is a pharmaceutically
acceptable cation, wherein x is the valence of the cation (its
charge); and a pharmaceutically acceptable carrier. By straight
chain alkyl is meant the non-branched methyl, ethyl, n-propyl,
n-butyl, n-decyl, and etc. groups. By branched chain alkyl is meant
groups like 3-methylpentyl, 2-ethylpropyl, and etc. The proviso
means that groups like isopropyl or 1-methylbutyl are excluded. The
C.sub.2 to C.sub.6 alkyls are preferred. Of the R.sub.1 R.sub.2 N-
heterocyclic groups, morpholino is preferred. By a pharmaceutically
acceptable cation is meant any non-toxic cation; these are well
known to one of ordinary skill in the art. The cation should not
render the compound unstable or insoluble in water. Generally the
cation will be a group 1 or group 2 cation, such as sodium,
potassium, magnesium or calcium ions, or NR.sub.3 R.sub.4 R.sub.5
R.sub.6.sup.+, wherein R.sub.3, R.sub.4, R.sub.5, and R.sub.6 are
independently chosen from H, C.sub.1 -C.sub.12 alkyl, C.sub.3
-C.sub.7 cycloalkyl or benzyl, more preferably H, C.sub.1 -C.sub.4
alkyl or C.sub.6 cycloalkyl. The method of synthesis discussed
below first results in the cation being R.sub.1 R.sub.2 H.sub.2
N.sup.+, these cations work well. The most preferred cations are
Na.sup.+, K.sup.+, Ca.sup.+2, and R.sub.1 R.sub.2 H.sub.2
N.sup.+.
The compositions are potent anti-hypertensives. They are useful for
lowering the blood pressure and treating any cardiovascular
disorder in which lowering the blood pressure will have a
beneficial effect. The invention provides an effective method of
lowering the blood pressure by administering the composition to a
mammal.
The methods of synthesis are the same as disclosed by Drago et al.,
J. Amer. Chem. Soc., 83, 1819-1822,1961. Generally, the secondary
amine (R.sub.1 R.sub.2 HN) is dissolved in anhydrous ether, oxygen
is removed from the system, the temperature is lowered to
-78.degree. C., and dry NO is bubbled through the ether solution.
The reaction can be run at high pressure (100 psi) or at
atmospheric pressure. The same product is obtained, but the yields
are higher using the high pressure method. The same method is used
to make all the compounds, the only difference being the starting
secondary amine. Example 1 gives the details of how the
diethylamine complex was made.
EXAMPLE 1a
Anhydrous diethylamine (100ml) was dissolved in 100ml of anhydrous
diethyl ether and was placed in a three-necked flask. Two of the
necks served as inlets for N.sub.2 and NO, and the third was an
outlet. The flask was flushed with N.sub.2 and the mixture cooled
to -78.degree. C. using an acetone-dry ice bath. Commercial grade
NO was bubbled through 10M NaOH and dried by passing it through a
column containing NaOH pellets, and then bubbled for 3 hr through
the diethylamine/diethyl ether solution. The mixture was allowed to
warm to room temperature overnight (18 hr). The product
precipitated from solution. The product was filtered and washed
with diethyl ether. Three grams (3% yield) of crude product was
obtained. The product was purified by suspending it in diethyl
ether, adding sufficient neutralized chloroform dropwise to just
dissolve the product, and placing the mixture in the freezer. The
resultant crystals were then filtered, washed with diethyl ether
and dried by vacuum.
.sup.1 H NMR(200MHz):.delta.3.07(q,4H,J=7.2 Hz),2.94(q,
4H,J=7.2Hz),1.27(t, 6H, J=7.2Hz), 0.96(q,6H,J=7.2 Hz).
.sup.13 C NMR(50MHz):.delta.51.3, 45.2, 13.8, 13.5.
Calculated: C=46.56%, N=27.17%, H=10.75%
Found: C=46.49%, N=26.29, H=11.20%
The above physico-chemical characteristics correspond to the
structure: ##STR4##
EXAMPLE 1b
In the high pressure method a Parr shaker was used. NO was added to
the reservoir which makes it possible to fill the reaction vessel
without opening it directly to the NO tank. The mixture of
diethylamine (100ml) and diethyl ether (100 ml) was added to the
reaction vessel. The reaction vessel was cooled to -78.degree. C.
and subjected to several evacuation/nitrogen flush cycles to remove
as much of the oxygen as possible. NO was then introduced at a
pressure of about 100 psi. The reaction vessel was allowed to
slowly warm to room temperature overnight (18 hr), with shaking.
The excess NO was flushed off with N.sub.2 and the product was
filtered and washed with diethyl ether. The crude yield was 5
grams. Purification and analysis were the same as in example
1a.
The other secondary amine-NO complexes are made using the same
methods as examples 1a and 1b, the only difference being the
identity of the starting secondary amine. The product made in each
case has the formula R.sub.1 R.sub.2 NN.sub.2 O.sub.2 R.sub.1
R.sub.2 H.sub.2 N.sup.+. The synthesis of the salts containing the
other cations is done by conventional methods, most particularly by
a metathesis reaction, a method well known to one of ordinary skill
in the art. (See Drago et al.) To make the sodium salt of the
compound produced in example 1, the diethylammonium salt is
dissolved in ethyl alcohol and reacted with sodium ethoxide
according to the following reaction: R.sub.1 R.sub.2 NN.sub.2
O.sub.2 R.sub.1 R.sub.2 H.sub.2 N.sup.+ +NaOEt.fwdarw.EtOH+R.sub.1
R.sub.2 NH+R.sub.1 R.sub.2 NN .sub.2 O.sub.2 Na.sup.+. The product
is precipitated by flooding the reaction mixture with ether and
then washed with neutralized chloroform. The other salts can be
made by similar metathesis reactions.
PHARMACOLOGICAL PROPERTIES
The effect on the mean arterial blood pressure and heart rate of
male Sprague-Dawley rats of the compositions of the invention was
measured using a standard technique. A pressure transducer (Bell
and Howell, type 4-327-I) was connected to the right carotid artery
via a catheter containing heparinized saline. The mean arterial
pressure and heart rate were recorded on a Gould (Model 2800)
8-channel recorder. The rats were anesthetized with nembutal at an
initial dose of 35 mg/kg body weight and recurrent smaller
injections as needed. The compounds were dissolved in a
pharmaceutical carrier and injected into the rats via a catheter in
the right femoral vein. Table 1 shows the results.
TABLE 1 ______________________________________ Dose Mean Arterial
Pressure Heart Rate (.mu.mole/ (mm Hg) (beats/min) Compound kg)
Initial Post Change Initial Post
______________________________________ (Et).sub.2 NN.sub.+2 O.sub.2
3.90 102 36 -66 480 480 (Et).sub.2 H.sub.2 SNP 0.34 113 56 -57 403
454 NaNO.sub.2 4.00 126 48 -78 360 420 NaNO.sub.3 42.00 117 120 3
420 420 ______________________________________
In Table 1, the pharmaceutical carrier was Abbott's 5% dextrose
USP, SNP, NaNO.sub.2, and NaNO.sub.3 were used as controls. SNP and
NaNO.sub.2 are known vasodilators, NaNO.sub.3 is the oxidative
breakdown product of NaNO.sub.2 and has little vasodilatory effect.
The results show that (Et).sub.2 NN.sub.2 O.sub.2 (Et).sub.2
H.sub.2 N.sup.+ is a potent anti-hypertensive, decreasing the blood
pressure significantly. The peak value of the blood pressure
decrease, shown in Table 1, takes only about 30 sec to 1 min to
occur, after injection, and the blood pressure starts to rise again
soon after and has totally recovered within 10-15 min.
The compositions of this invention are useful for treating any
cardiovascular disorder that will respond favorably to a decrease
in blood pressure. These disorders include chronic hypertension,
hypertensive crisis (an acute hypertensive emergency), acute
congestive heart failure, angina, acute myocardial infarction, left
ventricular failure, cerebrovascular insufficiency and intracranial
hemorrhage. Because of the fast response upon intravenous injection
the compositions are particularly advantageous for treating acute
disorders such as hypertensive crisis, toxemia of pregnancy and
acute congestive heart failure. The preferred method of
administration is by injection into the blood system, most
preferably by intravenous injection. The chronic disorders can be
treated by continuous intravenous infusion. A suitable dosage for
intravenous administration is about 0.01 to 10.0 mg/kg per day.
The pharmaceutical compositions of the invention are comprised of
the compounds of formula I and a pharmaceutical carrier. The
carrier can be any of those conventionally used and is limited only
by chemico-physical considerations such as solubility and lack of
reactivity with the compound and by the route of administration.
For intravenous administration, the carrier will be aqueous and may
contain solubilizing agents, buffers, preservatives, antioxidants,
chelating agents, and agents to control the tonicity , such as
dextrose or sodium chloride. The requirements for effective
pharmaceutical carriers for injectable compositions are well known
by one of ordinary skill in this art. (See "Pharmaceutics and
Pharmacy Practice", J.B. Lippincott Company, Philadelphia,
1982,edited by Banker and Chalmers, pages 238-250, which are
incorporated by reference, also see ASHP "Handbook on Injectable
Drugs" 4th edition by Trissel, pages 622-630, which lists
commercially available intravenous infusion solutions, these pages
are incorporated by reference.) The compounds may also be
formulated as inclusion complexes, such as, for example,
cyclodextrin inclusion complexes; or the compounds may be carried
within liposomes. Preferred pharmaceutical carriers for injection
are PBS (phosphate buffered saline), 5% dextrose and sterile water.
Since the compounds of formula I are subject to being oxidized by
oxygen, an antioxidant, such as ascorbate, can be added to the
carrier to increase the shelf-life.
* * * * *