U.S. patent application number 11/133720 was filed with the patent office on 2005-12-08 for levalbuterol hydrochloride polymorph a.
Invention is credited to Aronhime, Judith, Bianchi, Stefano, Daverio, Paola, Kovacsne-Mezei, Adrienne, Mantovani, Silvia, Merli, Valeriano, Spreafico, Angelo.
Application Number | 20050272821 11/133720 |
Document ID | / |
Family ID | 35456181 |
Filed Date | 2005-12-08 |
United States Patent
Application |
20050272821 |
Kind Code |
A1 |
Merli, Valeriano ; et
al. |
December 8, 2005 |
Levalbuterol hydrochloride Polymorph A
Abstract
The invention is directed to processes for making levalbuterol
HCl Polymorph A from by suspending or forming a first slurry of
(R)-SLB(D)-DBTA in at least a first organic solvent, adding HCl to
the suspension or slurry of the solid (R)-SLB.D-DBTA until the
(R)-SLB.D-DBTA forms levalbuterol HCl Polymorph A, and isolating
the levalbuterol HCl Polymorph A.
Inventors: |
Merli, Valeriano; (Cremella,
Lecco, IT) ; Mantovani, Silvia; (Lendinara, IT)
; Bianchi, Stefano; (Breccia, Como, IT) ; Daverio,
Paola; (Villasanta, Milano, IT) ; Spreafico,
Angelo; (Lecco, IT) ; Aronhime, Judith;
(Rehovot, IL) ; Kovacsne-Mezei, Adrienne;
(Debrecen, HU) |
Correspondence
Address: |
KENYON & KENYON
ONE BROADWAY
NEW YORK
NY
10004
US
|
Family ID: |
35456181 |
Appl. No.: |
11/133720 |
Filed: |
May 20, 2005 |
Related U.S. Patent Documents
|
|
|
|
|
|
Application
Number |
Filing Date |
Patent Number |
|
|
60573025 |
May 20, 2004 |
|
|
|
60577979 |
Jun 7, 2004 |
|
|
|
60646803 |
Jan 25, 2005 |
|
|
|
60577819 |
Jun 7, 2004 |
|
|
|
60583777 |
Jun 28, 2004 |
|
|
|
60583642 |
Jun 28, 2004 |
|
|
|
60587673 |
Jul 13, 2004 |
|
|
|
60632625 |
Dec 2, 2004 |
|
|
|
Current U.S.
Class: |
514/649 ;
564/355 |
Current CPC
Class: |
C07C 217/48 20130101;
A61P 43/00 20180101; C07C 227/34 20130101; C07C 215/60 20130101;
C07C 229/38 20130101; C07C 229/38 20130101; C07C 227/34 20130101;
A61P 11/06 20180101; A61P 11/08 20180101; A61P 11/00 20180101 |
Class at
Publication: |
514/649 ;
564/355 |
International
Class: |
A61K 031/137 |
Claims
What is claimed is:
1. A process for making levalbuterol HCl Polymorph A comprising:
suspending or forming a first slurry of (R)-SLB(D)-DBTA in at least
a first organic solvent; adding HCl to the suspension or slurry of
the solid (R)-SLB.D-DBTA until the (R)-SLB.D-DBTA forms pure
levalbuterol HCl Polymorph A; and isolating the pure levalbuterol
HCl Polymorph A.
2. The process according to claim 1, wherein the first organic
solvent is at least one linear or branched C.sub.3-C.sub.10 ester,
linear or branched C.sub.3-C.sub.10 ketone, linear or branched
C.sub.3-C.sub.10 ether, aromatic hydrocarbon, linear or branched
C.sub.1-C.sub.4 alcohol, dimethylsulfoxide, dimethylformamide,
methylene chloride, or acetonitrile.
3. The process according to claim 1, wherein the first solvent is
at least one of ethylacetate, tetrahydrofuran, dimethylcarbonate,
acetonitrile, toluene, methanol, dimethylsulfoxide, or
dimethylforamide.
4. The process according to claim 2, wherein the aromatic
hydrocarbon is C.sub.6 to C.sub.10.
5. The process according to claim 1, wherein the first solvent
comprises two solvents.
6. The process according to claim 5, wherein one solvent is present
in about 70% and a second solvent is present in about 30% by
volume.
7. The process according to claim 5, wherein the first solvent
comprises ethylacetate present in about 70% to 100% and methanol
present in about 1% to 30% by volume.
8. The process according to claim 7, wherein the first solvent
comprises ethylacetate present in 95% and methanol present in about
5% by volume.
9. The process according to claim 1, wherein the HCl is at least
one of aqueous HCl (37%), HCl gas, HCl in DMF, or HCl in ether.
10. The process according to claim 1, further comprising suspending
or forming a second slurry of the pure levalbuterol HCl Polymorph A
in a second solvent; and isolating the pure levalbuterol HCl
Polymorph A.
11. The process according to claim 10, wherein the second solvent
is at least one C.sub.3-C.sub.5 ester, C.sub.6-C.sub.7 aromatic
hydrocarbon, C.sub.1-C.sub.2 alcohol, dimethylsulfoxide,
dimethylformamide, dichloromethane, or acetonitrile.
12. The process according to claim 11, wherein the second solvent
is at least one of ethyl acetate, dimethyl carbonate, acetonitrile,
toluene, methanol, dimethylsulfoxide, or dimethylformamide.
13. A process for making pure levalbuterol HCl Polymorph A by the
conversion of levalbuterol HCl Polymorph B into pure levalbuterol
Polymorph A comprising: forming a slurry or suspension of
levalbuterol HCl Polymorph B with an organic solvent mixture; and
isolating pure levalbuterol Polymorph A from the slurry or
suspension.
14. The process according to claim 13, wherein the organic solvent
is at least one linear or branched C.sub.3-C.sub.10 ester, linear
or branched C.sub.3-C.sub.10 ketone, linear or branched
C.sub.3-C.sub.10 ether, C.sub.6-C.sub.10 aromatic hydrocarbon,
linear or branched C.sub.1-C.sub.4 alcohol, dimethylsulfoxide,
dimethylformamide, methylene chloride, or acetonitrile.
15. The process according to claim 13, wherein the first solvent is
at least one of ethylacetate, tetrahydrofuran, dimethylcarbonate,
acetonitrile, toluene, methanol, dimethylsulfoxide, or
dimethylforamide.
16. Levalbuterol HCl polymorph A having levalbuterol HCl Polymorph
B in an amount of not more than about 5% by weight.
17. The levalbuterol HCl Polymorph A according to claim 16, wherein
the levalbuterol HCl Polymorph B is present in an amount of not
more than 3% by weight.
18. The levalbuterol HCl Polymorph according to claim 16, wherein
the levalbuterol HCl Polymorph B is present in an amount of not
more than 1% by weight.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims the benefits of U.S. Provisional
Patent Application Nos. 60/573,025, filed May 20, 2004, 60/577,979,
filed Jun. 7, 2004, 60/646,803, filed Jan. 25, 2005, 60/577,819,
filed Jun. 7, 2004, 60/583,777, filed Jun. 28, 2004, 60/583,642,
filed Jun. 28, 2004, 60/587,673, filed Jul. 13, 2004 and
60/632,625, filed Dec. 2, 2004, the contents of all of which are
incorporated herein by reference.
FIELD OF THE INVENTION
[0002] The present invention encompasses processes for the
preparation of levalbuterol hydrochloride Polymorph A and to pure
forms thereof.
BACKGROUND OF THE INVENTION
[0003] Activation of .beta..sub.2-adrenergic receptors on airway
smooth muscle leads to the activation of adenylcyclase and to an
increase in the intracellular concentration of
cyclic-3',5'-adenosine monophosphate (cyclic AMP). This increase in
cyclic AMP leads to the activation of protein kinase A, which
inhibits the phosphorylation of myosin and lowers intracellular
ionic calcium concentrations, resulting in relaxation. Levalbuterol
relaxes the smooth muscles of the airways from the trachea to the
terminal bronchioles. Levalbuterol acts as a functional antagonist
to relax the airway irrespective of the spasmogen involved, thus
protecting against all bronchoconstrictor challenges. Increased
cyclic AMP concentrations are also associated with the inhibition
of release of mediators from mast cells in the airway. The chemical
name for levalbuterol HCl is
(R)-.alpha..sup.1-[[(1,1-dimethylethyl)amino]methyl]--
4-hydroxy-1,3-benzenedimethanol hydrochloride.
[0004] Levalbuterol HCl has been synthesized using a variety of
synthetic schemes. For example, Great Britain patent No. 1298494
discloses synthesizing levalbuterol first by crystallizing the
alkyl acetate of the 4-carboxylate derivative (Formula 1) using
ditolyltartaric acid and isolating the selected crystalline
fraction. 1
[0005] Thereafter, the crystal undergoes debenzylation
deprotection, followed by ester reduction to yield
levalbuterol.
[0006] Chinese patent No. 1,273,966, the salt of (R)-albuterol
D-dibenzoyltartaric acid is treated with potassium carbonate in
water and an organic solvent, such as ethylacetate. After phase
separation and extraction of the aqueous layer, the collected
organic layer is dried and levalbuterol free base crystallizes
overnight. The crystalline levalbuterol free base is dissolved in
anhydrous alcohol, followed by addition of HCl to obtain
crystalline levalbuterol HCl. Also, levalbuterol HCl is synthesized
by acid displacement from (R)-albuterol D-dibenzoyltartaric acid
salt suspended in acetone and the addition of an ether solution of
HCl.
[0007] Despite the many attempts of the prior art to synthesize
pure levalbuterol, still novel synthetic processes of preparing
polymerically pure levalbuterol are needed to reduce the steps
necessary for synthesis.
SUMMARY OF THE INVENTION
[0008] The invention encompasses processes for making levalbuterol
HCl Polymorph A comprising suspending or forming a first slurry of
(R)-SLB(D)-DBTA
(((R)(-).alpha..sup.1-[[(1,1-dimethylethyl)amino]methyl]--
benzenedimethanol.(D)-Dibenzoyltartrate) in at least a first
organic solvent; adding HCl to the suspension or slurry of the
solid (R)-SLB.D-DBTA until the (R)-SLB.D-DBTA forms pure
levalbuterol HCl Polymorph A; and isolating the pure levalbuterol
HCl Polymorph A. The first solvent may be at least one linear or
branched C.sub.3-C.sub.10 ester, linear or branched
C.sub.3-C.sub.10 ketone, linear or branched C.sub.3-C.sub.10 ether,
C.sub.6-C.sub.10 aromatic hydrocarbon, linear or branched
C.sub.1-C.sub.4 alcohol, dimethylsulfoxide, dimethylformamide,
methylene chloride, or acetonitrile. Preferably, the first solvent
is at least one of ethyl acetate, tetrahydrofuran, dimethyl
carbonate, acetonitrile, toluene, methanol, dimethylsulfoxide, or
dimethylforamide.
[0009] Preferably, the process further comprises chemical
purification of the pure levalbuterol HCl Polymorph A by suspending
or forming a second slurry of the pure levalbuterol HCl Polymorph A
in a second solvent; and isolating the pure levalbuterol HCl
Polymorph A. Preferably, the second solvent comprises 95%
ethylacetate and about 5% methanol by volume.
[0010] The invention also encompasses processes for making pure
levalbuterol HCl Polymorph A by the conversion of levalbuterol HCl
Polymorph B into pure levalbuterol Polymorph A comprising forming a
slurry or suspension of levalbuterol HCl Polymorph B with a first
organic solvent mixture as described above; and isolating pure
levalbuterol Polymorph A from the slurry or suspension.
[0011] The invention also encompasses levalbuterol HCl polymorph A
having levalbuterol HCl Polymorph B in an amount of not more than
about 5% by weight. Preferably, the levalbuterol HCl Polymorph A
has levalbuterol HCl Polymorph B present in an amount of not more
than 3%, and more preferably, in an amount of not more than 1% by
weight.
BRIEF DESCRIPTION OF THE FIGURES
[0012] FIG. 1 illustrates levalbuterol HCl Polymorph A in a
crystalline particle size having a maximum particle size of about
150 microns.
DETAILED DESCRIPTION OF THE INVENTION
[0013] The present invention relates to the solid state physical
properties of levalbuterol HCl. These properties can be influenced
by controlling the conditions under which levalbuterol HCl is
obtained in solid form. Solid state physical properties include,
for example, the flowability of the milled solid. Flowability
affects the ease with which the material is handled during
processing into a pharmaceutical product. When particles of the
powdered compound do not flow past each other easily, a formulation
specialist must take that fact into account in developing a tablet
or capsule formulation, which may necessitate the use of glidants
such as colloidal silicon dioxide, talc, starch or tribasic calcium
phosphate.
[0014] Another important solid state property of a pharmaceutical
compound is its rate of dissolution in aqueous fluid. The rate of
dissolution of an active ingredient in a patient's stomach fluid
can have therapeutic consequences since it imposes an upper limit
on the rate at which an orally-administered active ingredient can
reach the patient's bloodstream. The rate of dissolution is also a
consideration in formulating syrups, elixirs and other liquid
medicaments. The solid state form of a compound may also affect its
behavior on compaction and its storage stability.
[0015] These practical physical characteristics are influenced by
the conformation and orientation of molecules in the unit cell,
which defines a particular polymorphic form of a substance. These
conformational and orientational factors in turn result in
particular intramolecular interactions and intermolecular
interactions with adjacent molecules that influence the macroscopic
properties of the bulk compound. A particular polymorphic form may
give rise to distinct spectroscopic properties that may be
detectable by powder X-ray diffraction, solid state 13C NMR
spectrometry and infrared spectrometry. The polymorphic form may
also give rise to thermal behavior different from that of the
amorphous material or another polymorphic form. Thermal behavior is
measured in the laboratory by such techniques as capillary melting
point, thermogravimetric analysis (TGA) and differential scanning
calorimetry (DSC) and can be used to distinguish some polymorphic
forms from others.
[0016] As used herein, the term: "(R)-SLB(D)-DBTA" refers to R
enantiomer of albuterol D-DBTA complex.
[0017] Polymorph A may be characterized either by x-ray diffraction
(XRD); infrared spectroscopy; or by differential scanning
calorimetry (DSC). Polymorph A is characterized using x-ray
diffraction by peaks at 10.7, 15.3, 15.6, 19.1, and 23.9 degree
two-theta, .+-.0.2 two-theta. Polymorph A may be further
characterized using x-ray diffraction peaks at 6.9, 20.7, 27.4, and
32.4 degree two-theta, .+-.0.2 two-theta. Alternatively, Polymorph
A is characterized by infrared peaks at 3534, 3414, 3087, 1437,
1304, and 1087 cm.sup.-1. Polymorph A may be further characterized
by IR peaks at 2979, 2797, 1613, 1547, 1505, 1481, 1397, 1365,
1325, 1243, 1199, 1152, 1109, 1076, 1056, 1030, 990, 920, 839, 792,
and 640 cm.sup.-1. Polymorph A is characterized by DSC data having
one endothermic peak due to melting at about 171.degree. C. to
193.degree. C. Polymorph A is also characterized by a Loss On
Drying (L.O.D.) of about 0.09% to 1.2% or a water content of 0.09
to 0.3% by weight.
[0018] The amount of levalbuterol HCl Polymorph B present in the
Polymorph A can easily be determined by comparing the
characteristic peak at 8.7 degree two-theta in an X-ray diffraction
pattern. As used herein, the term "pure levalbuterol HCl Polymorph
A" refers to levalbuterol HCl Polymorph A having levalbuterol HCl
Polymorph B in an amount less than about 5% by weight. Preferably,
the levalbuterol HCl Polymorph A does not contain more than 3% of
levalbuterol HCl Polymorph B, and most preferably not more than 1%
by weight.
[0019] The invention encompasses processes for preparing
levalbuterol Polymorph A with considerable simplicity. The process
for preparing pure levalbuterol Polymorph A comprises suspending or
forming a first slurry of the R enantiomer of albuterol D-DBTA
complex ("(R)-SLB.D-DBTA") in a first organic solvent; adding HCl
to the suspension of the solid (R)-SLB.D-DBTA until the
(R)-SLB.D-DBTA forms pure levalbuterol HCl Polymorph A; and
isolating the pure levalbuterol HCl Polymorph A. Not to be limited
by theory, it is believed that the process occurs by a solid to
solid transformation.
[0020] The first solvent includes, but is not limited to, at least
one linear or branched C.sub.3-C.sub.10 ester, linear or branched
C.sub.3-C.sub.10 ketone, linear or branched C.sub.3-C.sub.10 ether,
C.sub.6-C.sub.10 aromatic hydrocarbon, linear or branched
C.sub.1-C.sub.4 alcohol, dimethylsulfoxide, dimethylformamide,
methylene chloride, or acetonitrile. Optionally, the first solvent
includes water. Preferably, the first solvent includes, but is not
limited to, at least one of ethylacetate, tetrahydrofuran,
dimethylcarbonate, acetonitrile, toluene, methanol,
dimethylsulfoxide, or dimethylforamide. When the first solvent
comprises two solvents, one solvent is present in about 70% and the
other solvent is present in about 30% by volume. Preferably, the
first solvent comprises ethylacetate present in an amount of about
70% to 100% and methanol present in an amount of about 1% to 30% by
volume. More preferably, the first solvent comprises
ethylacetate:methanol in a ratio of about 90 to about 10 by volume,
and most preferably, in a ratio of 95:5 by volume.
[0021] The suspension or slurry may be carried out at temperatures
of about -10.degree. C. to about 40.degree. C., more preferably at
about room temperature.
[0022] The HCl may be added as a solution or a gas. For example,
methods for adding HCl include, but are not limited to, adding
aqueous HCl (37%), HCl gas, HCl in DMF, or HCl in ethereal
solutions. Typically, HCl is added in an amount of about 1.2
equivalents of HCl per equivalent of (R)-SLB.D-DBTA.
[0023] The first suspension or slurry may be cooled, preferably at
a temperature of about -10.degree. C. to about 10.degree. C., more
preferably at about -5.degree. C. to about 5.degree. C., and most
preferably at a about -2.degree. C. to about 2.degree. C.
[0024] Formation of pure levalbuterol polymorph A of the invention
is dependent upon the solvent(s) of the first suspension or
slurrying. Table 1 summarizes the solvents used to obtain pure
levalbuterol HCl Polymorph A.
1TABLE 1 Results of Different Reaction and Slurry Solvents DSC
Crystal peak Enthalpy Sample Solvents Form (.degree. C.) (J/g) 1
EtOAc-DMF A 182 (118) (90:10) 2 EtOAc-MeOH A 175 (123) (90:10) 3
Acetone-H.sub.2O A 190 (165) (95:5, 0.degree. C.) 4 EtOAc A 171
(127) 5 CH.sub.3CN A 179 (141) 6 IPA (filtered A 187 (128) at
0-2.degree. C.) 7 EtOAc-MeOH A 191 (92), 192 (47) (90:10), HCl 8
Acetonitrile A 189 (157) 9 Acetonitrile A 188 (131) 10 EtOAc-DMF A
181 (116) (90:10) 11 EtOAc-DMF A 188 (130) (90:10) 12 EtOAc-DMF A
184 (150) (90:10) 13 EtOAc-DMF A 189 (108) (90:10) 14 EtOAc-MeOH A
189 (153) (90:10) 15 EtOAc-MeOH A 193 (163) (95:5, 1-6 volumes) 16
EtOAc-MeOH A 185 (158) (95:5) 17 EtOAc-MeOH A 182 (134) (95:5) 18
EtOAc-MeOH A 193 (163) (90:10) 19 EtOAc-MeOH A 193 (160) (90:10) 20
EtOAc-MeOH A 189 (142) (90:10) 21 EtOAc-MeOH A 181 (121) (90:10),
HCl (5% MeOH) 22 EtOAc-MeOH A 183 (153) (90:10) 23 EtOAc-MeOH A 191
(130) (95:5) 24 Acetone A 194 (138) 25 Toluene A 190 (140) 26
EtOAc-MeOH A 193 (125) (90:10) 27 Isopropyl ether A 193 (122) 28
EtOAc-MeOH A 190 (119) (95:5) 29 EtOAc-MeOH A 189 (129) (95:5) 30
Dichloromethane A 193 (112) 31 Acetonitrile A 194 (118) 32 methyl
tert-butyl A 193 (117) ether (MTBE) 33 BuOAc A 194 (137) 34
Isopropanol A 194 (130)
[0025] The presence of the polymorph was determined by XRD and a
Differential Scanning Calorimetry (DSC) for each was taken. Based
on DSC curves of levalbuterol HCl, Polymorph A exhibits one
endothermic peak due to melting. Due to decomposition during
melting, a melting range of about 171.degree. C. to about
194.degree. C. was determined for Polymorph A.
[0026] Optionally, the process further comprises chemical
purification levalbuterol HCl Polymorph A by suspending or forming
a second slurry of the levalbuterol HCl Polymorph A in a second
solvent; and isolating pure levalbuterol HCl Polymorph A. As used
herein, the term "chemical purification" refers to the separation
of residual traces of D-DBTA from the levalbuterol HCl, by a slurry
or suspension.
[0027] The second solvent includes, but is not limited to, at least
one linear C.sub.3-C.sub.5 ester, C.sub.6-C.sub.7 aromatic
hydrocarbon, C.sub.1-C.sub.2 alcohol, dimethylsulfoxide,
dimethylformamide, dichloromethane, or acetonitrile. Preferably,
the second solvent includes, but is not limited to, at least one of
ethylacetate, dimethylcarbonate, acetonitrile, toluene, methanol,
dimethylsulfoxide, or dimethylformamide. Optionally the second
solvent may include water. When the second solvent comprises two
solvents, the ratio of solvents is about 90 to about 10 by volume.
Preferably, the ratio of solvents is about 95 to about 5 by volume.
More preferably, the second solvent is ethylacetate:methanol in a
ratio of 95:5 by volume.
[0028] The second slurry may be carried out at a temperature of
about -10.degree. C. to about the reflux temperature of the second
solvent.
[0029] After isolation, levalbuterol HCl Polymorph A may be dried,
such as at room temperature and/or under reduced pressure. "Reduced
pressure" refers to a pressure of less than one atmosphere, such as
about 40 mm Hg to about 50 mm Hg.
[0030] The invention also encompasses a process for making pure
levalbuterol HCl Polymorph A by the conversion of levalbuterol HCl
Polymorph B into pure levalbuterol Polymorph A. The process
comprises providing levalbuterol HCl Polymorph B, forming a slurry
or suspension of levalbuterol HCl Polymorph B with an organic
solvent mixture, and isolating pure levalbuterol Polymorph A from
the slurry. The organic solvent includes, but is not limited to, at
least one linear or branched C.sub.3-C.sub.10 ester, linear or
branched C.sub.3-C.sub.10 ketone, linear or branched
C.sub.3-C.sub.10 ether, C.sub.6 to C.sub.10 aromatic hydrocarbon,
linear or branched C.sub.1-C.sub.4 alcohol, dimethylsulfoxide,
dimethylformamide, methylene chloride, or acetonitrile. Optionally,
the organic solvent includes water. Preferably, the organic solvent
includes, but is not limited to, at least one of ethylacetate,
tetrahydrofuran, dimethylcarbonate, acetonitrile, toluene,
methanol, dimethylsulfoxide, or dimethylforamide. Typically, the
temperature may be any suitable temperature wherein the conversion
takes place, preferably the temperature is about 25.degree. C. to
30.degree. C., more preferably, the temperature is about room
temperature.
[0031] Table 2 summarizes the loss on drying (LOD) as a weight
percentage over a temperature range and water content for Polymorph
A of levalbuterol.
2TABLE 2 Thermal Gravimetric Analysis (TGA) and Water Content for
Sample Polymorphs. TGA Water Content Sample Crystal Form LOD (%)
Temp (.degree. C.) (%) 1 A 0.30 27-102 0.36 2 A 0.30 46-102 0.45 4
A 0.28 33-131 0.29 7 A 0.09 38-133 0.16 10 A 1.17 50-102 0.30 14 A
0.03 53-153 0.09
[0032] Table 3 summarizes the hygroscopicity and crystal structure
of a sample of levalbuterol HCl 100% Polymorph A after exposure to
different levels of humidity for one week. After each exposure the
water content was determined by Thermal Gravimetric Analysis (TGA)
and reported as loss on drying (LOD) as a weight percentage. The
crystal structure was determined by X-ray Diffraction (XRD). Based
on the observations, after exposure of each sample to up to about
80% relative humidity, the water content of Polymorph A was
determined to be only about 0.23 to 0.97 percent. After exposure of
each sample at about 100% relative humidity for one week, the water
content of Polymorph A was determined to be about 34 percent.
3TABLE 3 Results of hygroscopicity test of levalbuterol HCl
Polymorph A RH (%) LOD (%).sup.a (Polymorph A) Form by XRD.sup.b
(Polymorph A) 0 0.23 A 20 0.48 A 40 0.70 A 60 0.72 A 80 0.97 A 100
34.0 A .sup.aThe water content of each individual sample of
Polymorph A after being exposed to the various levels of relative
humidity (RH %) of column one, equilibrated and analyzed by thermal
gravimetric analysis. .sup.bThe crystal structure of each
individual sample of Polymorph A after being exposed to the various
levels of relative humidity (RH %) of column one, equilibrated and
analyzed by x-ray diffraction.
[0033] While the present invention is described with respect to
particular examples and preferred embodiments, it is understood
that the present invention is not limited to these examples and
embodiments. The present invention, as claimed, therefore includes
variations from the particular examples and preferred embodiments
described herein, as will be apparent to one of skill in the
art.
EXAMPLES
[0034] The X-Ray diffraction (XRD) analysis was conducted using an
ARL X-Ray powder diffractometer (model X'TRA-030) equipped with a
Peltier detector, round standard aluminum sample holder with round
zero background, and quartz plate. The scanning parameters were
from a range of about 2-40 degree two .theta. (.+-.0.2 degrees) and
a continuous scan at a rate of about 3 degrees/min. One of ordinary
skill in the art understands that experimental differences may
arise due to differences in instrumentation, sample preparation, or
other factors.
[0035] Fourier transform infrared (FT-IR) spectroscopy was
conducted using a Perkin-Elmer Spectrum 1000 Spectrometer at about
4 cm.sup.-1 resolution with about 16 scans in the range of 4000-400
cm.sup.-1. Samples were analyzed in KBr pellet and the instrument
was calibrated using an empty cell as a background.
[0036] Differential scanning calorimetry (DSC) was conducted using
a Mettler Toledo DSC 822.sup.e/700 with a sample weight of about
3-5 mg, a heating rate of about 10.degree. C./min., using a 3 holed
crucible, under a stream of N.sub.2 at a flow rate of about 40
ml/min. The sample was scanned between a range of about 30.degree.
C. to about 250.degree. C. at a heating rate of about 10.degree.
C./minute.
[0037] Thermal Gravimetric Analysis (TGA) was conducted using a
Mettler Toledo TGA/SDTA 851.sup.e using a sample weight of about
7-15 mg, a heating rate of about 10.degree. C./min. under a N.sub.2
stream at a N.sub.2 flow rate of about 50 ml/min. The samples were
scanned at a range between about 30.degree. C. to about 250.degree.
C.
[0038] The HPLC analysis was conducted using a column POLARIS C18-A
250 mm.times.4.6 mm.times.5.0 mm (cat n.2002-250x046) and a mobile
phase. The mobile phase comprised a gradient of phosphate buffer at
about pH 3.00 and acetonitrile. The eluent flow was about 1.0
ml/min. An HP 1100 HPLC Hewlett Packard VWD detector was set to a
wavelength of about 230 nm.
Example 1
[0039] In a 500 ml reactor equipped with a condenser, thermometer,
and mechanical stirrer loaded at room temperature and under
nitrogen a suspension of wet pure (R)-SLB.(D)-DBTA (30 g wet, 25.4
g at 100%; 0.0425 moles) in acetonitrile (300 ml) was formed. The
suspension was cooled to 0.degree. C..+-.2.degree. C., the
temperature was maintained, and in about 5 minutes HCl (37%, 5.0 g,
0.051 moles, 1.2 eq.) was added. The suspension was stirred at
0.degree. C..+-.2.degree. C. for 1 hour; the solid was collected by
filtration and washed with acetonitrile (3.times.16 ml). The wet
solid (15.1 g) was suspended in an ethylacetate and methanol
mixture (75 ml, 90:10 v/v), and the suspension was stirred at
20.degree. C. to 25.degree. C. for 4 hrs. The solid was collected
by filtration and washed with ethylacetate to obtain levalbuterol
HCl Polymorph A (11 g dry weight, 95%).
Example 2
[0040] In a 1000 ml reactor equipped with a condenser, thermometer,
and mechanical stirrer loaded at room temperature and under
nitrogen a suspension of wet pure (R)-SLB.(D)-DBTA (93.96 g, 70 g
at 100%, 0.117 moles) in ethylacetate (729 ml) and methanol (84 ml)
was formed. The suspension was cooled to 0.degree. C..+-.2.degree.
C., maintained at the temperature, and in about 2 minutes HCl
(37.3%, 13.73 g, 0.14 moles, 1.2 eq.) was added. The suspension was
stirred at 0.degree. C..+-.2.degree. C. for 1 hour, and then the
solid was collected by filtration and washed with ethylacetate
(2.times.55 ml). The solid was dried at 22.degree. C..+-.2.degree.
C. under vacuum (40 to 45 mm Hg) for 20 hours to obtain
levalbuterol HCl Polymorph A (32 g dry weight).
Example 3
[0041] In a 500 ml reactor equipped with a condenser, thermometer,
and mechanical stirrer loaded at room temperature and under
nitrogen a suspension of wet pure (R)-SLB.(D)-DBTA (26.5 g wet, 20
g at 100%, 0.033 moles) in ethylacetate (233 ml) was formed. The
suspension was cooled to 0.degree. C..+-.2.degree. C. and
maintained at that temperature, and in about 2 minutes a solution
of HCl (37.3%, 3.93 g, 0.04 moles, 1.2 eq.) was added. The
suspension was stirred at 0.degree. C..+-.2.degree. C. for 1 hour;
the solid collected by filtration and washed with ethylacetate
(2.times.17.5 ml). The wet product (9.3 g) was dried at 22.degree.
C..+-.2.degree. C. under vacuum (40 to 45 mm Hg) for 20 hours to
obtain levalbuterol Polymorph A (9 g dry weight.
Example 4
[0042] In a 500 ml reactor equipped with a condenser, thermometer,
and mechanical stirrer loaded at room temperature and under
nitrogen a suspension of wet pure (R)-SLB.(D)-DBTA (30 g wet, 25.4
g at 100%, 0.0425 moles), ethylacetate (243 ml), and DMF (26.9 ml)
was formed. The suspension was cooled to 0.degree. C..+-.2.degree.
C., maintained at the temperature, and in about 5 minutes HCl (37%,
4.54 g, 0.046 moles, 1.1 eq.) was added. The suspension was stirred
at 0.degree. C..+-.2.degree. C. for 1 hour; the solid was collected
by filtration, and washed with ethylacetate-DMF (90:10).
[0043] The wet product (15.5 g) was suspended in a mixture of
ethylacetate and methanol (75 ml, 90:10 v/v). The suspension was
stirred at 20.degree. C. to 25.degree. C. for four hours and a
solid was collected by filtration. The solid was washed with
ethylacetate, dried at 22.degree. C..+-.2.degree. C. under vacuum
(40 to 45 mm Hg) for 20 hours to obtain levalbuterol Polymorph A
(11 g dry weight, 93.9% yield).
Example 5
[0044] In a 500 ml reactor equipped with a condenser, thermometer,
and mechanical stirrer loaded at room temperature and under
nitrogen a suspension of wet pure (R)-SLB.(D)-DBTA (39.73 g wet, 30
g at 100%; 0.05 moles), in ethylacetate (331 ml) and MeOH (18 ml)
was formed. The suspension was cooled to 0.degree. C..+-.2.degree.
C., the temperature was maintained, and in about 5 minutes HCl
(37%, 5.89 g, 0.06 moles, 1.2 eq.) was added. The suspension was
stirred at 0.degree. C..+-.2.degree. C. for 1 hour, the solid was
collected by filtration, and washed with ethylacetate (3.times.16
ml). The wet solid (18.1 g) was suspended in an ethylacetate and
methanol mixture (90 ml, 90:10 v/v) and the suspension was stirred
at 20.degree. C. to 25.degree. C. for 4 hrs. The solid was
collected by filtration and washed with ethylacetate to obtain
levalbuterol HCl Polymorph A (12.9 g dry weight, 94%) in 99.9%
purity as determined by HPLC (any impurity <0.1%).
Example 6
[0045] In a 500 ml reactor equipped with a condenser, thermometer,
and mechanical stirrer loaded at room temperature and under
nitrogen a suspension of wet pure (R)-SLB.(D)-DBTA (30 g, 25.4 g at
100%, 0.0425 moles) in acetonitrile (300 ml) was formed. The
suspension was cooled to 0.degree. C..+-.2.degree. C., maintained
at the temperature, and in about 5 minutes HCl (37%, 5.0 g, 0.051
moles, 1.2 eq.) was added. The suspension was stirred at 0.degree.
C..+-.2.degree. C. for 1 hour, and then the solid was collected by
filtration, which was washed with acetonitrile (3.times.16 ml). The
wet solid (15.1 g) was suspended in a mixture of ethylacetate and
methanol (75 ml, 90:10 v/v), and the suspension was stirred at
20.degree. C. to 25.degree. C. for 4 hrs. The solid was collected
by filtration and washed with ethylacetate to obtain levalbuterol
HCl Polymorph A (11 g dry weight, 95%) in 99.8% purity as
determined by HPLC (any impurity <0.1%).
Example 7
[0046] In a 100 ml reactor equipped with a condenser, thermometer,
and mechanical stirrer loaded at room temperature and under
nitrogen a suspension of wet pure (R)-SLB.(D)-DBTA (8 g, 0.013
moles, 1 eq.) and isopropanol (40 ml). The suspension was cooled at
15.degree. C. to 20.degree. C. and HCl in methanol (31.2%, 1.82 g,
0.016 moles, 1.16 eq.) was added. The suspension was stirred at
room temperature, cooled to 0.degree. C. to 2.degree. C. for 1
hour, the solid was collected by filtration, and washed with
isopropanol (5 ml) and then ethylacetate (2.times.5 ml). After
drying, levalbuterol Polymorph A was collected (3 g).
Example 8
[0047] In a 50 ml reactor equipped with a condenser, thermometer,
and mechanical stirrer loaded at room temperature and under
nitrogen a suspension of wet pure (R)-LVL.HCl Polymorph B (8 g),
ethylacetate (36 ml), and methanol (4 ml) was formed. The
suspension was stirred at 23.degree. C. to 24.degree. C. and a
sample was taken at time intervals of 4 hours, 8 hours, 20 hours,
and 24 hours. Each sample taken was cooled to 0.degree. C. to
2.degree. C. for 1 hour, filtered, and the solid collected was
washed with isopropanol (5 ml) followed by ethylacetate (2.times.5
ml). The samples were dried and analyzed by FT-IR spectroscopy and
X-ray diffraction to detect the presence of levalbuterol HCl
Polymorph A.
Example 9
[0048] In a 500 ml reactor equipped with a condenser, thermometer,
and mechanical stirrer loaded at room temperature and under
nitrogen a suspension of wet pure (R)-SLB.(D)-DBTA (30 g wet, 25.4
g at 100%, 0.0425 moles), ethylacetate (243 ml) and DMF (26.9 ml).
The suspension was cooled at 0.degree. C..+-.2.degree. C., the
temperature was maintained, and in about 5 minutes HCl (37%, 4.54
g, 0.046 moles, 1.1 eq.). The suspension was stirred at 0.degree.
C..+-.2.degree. C. for 1 hour, the solid was collected by
filtration, and washed with ethylacetate-DMF (90:10) and then with
ethylacetate. The wet solid (15.5 g) was suspended in a mixture of
ethylacetate and methanol (75 ml, 90:10 v/v). The suspension was
stirred at 20.degree. C. to 25.degree. C. for 4 hrs, the solid was
collected by filtration and washed with ethylacetate. Levalbuterol
Polymorph A was collected (11 g, dry weight, 93.9%) in 99.7% purity
as determined by HPLC (any impurity <0.1%).
Example 10
[0049] Prior art examples were repeated, which results are
summarized in Table 4. In particular, Example 18 of Chinese patent
No. 1273966 and Example 7 of WO 95/32178 was repeated.
4TABLE 4 Results of Prior Art Examples Examp Solvent/Temp/ Xtal %
Form B No. Time Conditions Form in Form A 11.sup.a Lvl base in EtOH
According to A >5 + HCl in Et.sub.2O + CN 1273966 Et.sub.2O
example 18 12.sup.b Xtl. No. 11 from According to A >5 EtOH-MTBE
CN 1273966 example 18 13.sup.a Lvl base in EtOH According to A
>5 + HCl in Et.sub.2O + WO 95/32178 MTBE example 7 14.sup.b Xtl.
No. 13 from According to A >5 EtOH-MTBE WO 95/32178 example 7
15.sup.a R-SLB.DBTA + According to A > B >9 Acetone CN
1273966 + HCl in Et.sub.20 example 19 b Xtl. No. 15 from According
to A >5 EtOH-MTBE CN 1273966 example 19 .sup.aThe stating
material was a crude sample of levalbuterol base. .sup.bThe
starting material was a purified sample of levalbuterol HCl of the
prior example.
Example 11
Repetition of Example 18 of CN 1273966
[0050] In a 50 ml reactor equipped with a condenser, thermometer,
and mechanical stirrer loaded at room temperature levalbuterol free
base (3.2 g wet, 3 g at 100%) and absolute ethanol (12.5 ml). The
solution was cooled at 0.degree. C. to 5.degree. C. and ethereal
HCl 1.0 N (12 ml) was added. The suspension was warmed to room
temperature and after 30 min MTBE (12.5 ml) was added. After an
additional 30 min at room temperature, the suspension was cooled at
0.degree. C. to 5.degree. C. and after 2 hours, the solid was
collected by filtration and washed with MTBE (3 ml) to obtain
levalbuterol Polymorph A (1.75 g). Levalbuterol HCl Polymorph B was
present in an amount greater than 5% by weight.
Example 12
Recrystallization of Example 11 Product
[0051] In a 25 ml reactor equipped with a condenser, thermometer,
and mechanical stirrer loaded at room temperature levalbuterol HCl
(1 g) and absolute ethanol (19 ml). The solution was warmed to
45.degree. C. to 50.degree. C. to obtain a solution. The solution
was cooled to room temperature and after MTBE (9.5 ml) was added.
The solution was stirred at room temperature for 1 hour to obtain a
suspension. The solid was collected by filtration and washed with
MTBE (3 ml) to obtain levalbuterol Polymorph A (0.6 g).
Levalbuterol HCl Polymorph B was present in an amount greater than
5% by weight.
Example 13
Repetition of Example 18 of CN 1273966
[0052] In a 100 ml reactor equipped with a condenser, thermometer,
and mechanical stirrer loaded at room temperature and under
nitrogen a suspension of wet pure (R)-SLB.(D)-DBTA (5 g) and
acetone (50 ml). The suspension was cooled at 30.degree. C. and HCl
ethereal solution 1.56 N (14 ml) and ether (50 ml) was added. The
suspension was stirred at room temperature for 15 min, the solid
was collected by filtration and washed with ether (5 ml) to obtain
a mixture of levalbuterol Polymorph A>Polymorph B (1.9 g).
Levalbuterol HCl Polymorph B was present in an amount greater than
5% by weight.
Example 14
Recrystallization of Example 13 Product
[0053] In a 25 ml reactor equipped with a condenser, thermometer,
and mechanical stirrer loaded at room temperature levalbuterol HCl
(1.2 g) and absolute ethanol (15 ml). The solution was warmed to
45.degree. C. to 50.degree. to obtain a solution. The solution was
cooled to room temperature and after MTBE (8.75 ml) was added. The
solution was stirred at 15.degree. C. for 2 hours to obtain a
suspension. The solid was collected by filtration and washed with
MTBE (3 ml) to obtain levalbuterol Polymorph A (0.8 g).
Levalbuterol HCl Polymorph B was present in an amount greater than
5% by weight.
Example 15
Repetition of Example 18 of CN 1273966
[0054] In a 500 ml reactor equipped with a mechanical stirrer
loaded at room temperature levalbuterol HCl (35 g), K.sub.2CO.sub.3
(15%, 200 ml), and ethylacetate (200 ml) to obtain a two phase
solution. The solution was stirred at room temperature, the phases
separated, and the aqueous phase was extracted with ethylacetate
(4.times.100 ml). The organic layers were collected, dried, and
treated with activated charcoal (1 g). The solvent was removed by
distillation to obtain levalbuterol free base as a solid (8.7 g).
The potentiometric assay of the solid yielded 94.5%. Levalbuterol
HCl Polymorph B was present in an amount greater than 9% by
weight.
Example 16
Standard Reaction
[0055] In a 2000 ml reactor equipped with a condenser, thermometer,
and mechanical stirrer loaded at room temperature and under
nitrogen a suspension of wet pure (R)-SLB.(D)-DBTA (112 g wet, 100
g at 100%, 0.1673 moles), ethylacetate (1127 ml) and methanol (60
ml) was formed. The suspension was cooled at 0 EC.+-.2.degree. C.,
the temperature was maintained, and in about 12 minutes HCl (37%,
19.8 g, 0.2007 moles, 1.2 eq.) was added. The suspension was
stirred at 0 EC.+-.2.degree. C. for 1 hour, the solid was collected
by filtration, and washed with ethylacetate-methanol (95:5, 50 ml)
and then with ethylacetate alone (2.times.50 ml).
[0056] The wet solid (59.6 g) was suspended in a mixture of
ethylacetate and methanol (99 ml, 90:10 v/v). The suspension was
stirred at 10 EC for 4 hrs, the solid was collected by filtration
and washed with a mixture of ethylacetate and methanol (90:10) and
then ethylacetate (2.times.20 ml). Levalbuterol Polymorph A was
collected (14.67 g, dry weight) in 99.73% purity as determined by
HPLC.
* * * * *