U.S. patent application number 09/753655 was filed with the patent office on 2001-09-20 for new crystalline forms.
This patent application is currently assigned to Astra Aktiebolag. Invention is credited to Edvardsson, Daniel, Hedstrom, Lena, Lundblad, Anita, Pettersson, Ursula.
Application Number | 20010023244 09/753655 |
Document ID | / |
Family ID | 20412468 |
Filed Date | 2001-09-20 |
United States Patent
Application |
20010023244 |
Kind Code |
A1 |
Edvardsson, Daniel ; et
al. |
September 20, 2001 |
New crystalline forms
Abstract
There is provided EtO.sub.2C--CH.sub.2--(R)Cgl--Aze--Pab--OH, or
a pharmaceutically-acceptable salt thereof, in a form which is
substantially crystalline. It has been found that crystalline forms
of EtO.sub.2C--CH.sub.2--(R)Cgl--Aze--Pab--OH have a high chemical
and solid state stability when compared to amorphous forms of the
compound.
Inventors: |
Edvardsson, Daniel;
(Sodertalje, SE) ; Hedstrom, Lena; (Taby, SE)
; Lundblad, Anita; (Vastra Frolunda, SE) ;
Pettersson, Ursula; (Sodertalje, SE) |
Correspondence
Address: |
NIXON & VANDERHYE P.C.
1100 N. Glebe Rd., 8th Floor
Arlington
VA
22201
US
|
Assignee: |
Astra Aktiebolag
|
Family ID: |
20412468 |
Appl. No.: |
09/753655 |
Filed: |
January 4, 2001 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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09753655 |
Jan 4, 2001 |
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09424770 |
Nov 30, 1999 |
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6225287 |
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Current U.S.
Class: |
514/13.7 ;
548/953 |
Current CPC
Class: |
C07K 5/06026 20130101;
A61P 7/02 20180101; A61K 38/00 20130101; A61P 43/00 20180101; C07K
5/0222 20130101 |
Class at
Publication: |
514/19 ;
548/953 |
International
Class: |
A61K 038/05; C07D
25/04 |
Foreign Application Data
Date |
Code |
Application Number |
Sep 3, 1998 |
SE |
9802974-7 |
Claims
1. A substantially crystalline form of
EtO.sub.2C--CH.sub.2--(R)Cgl--Aze--- Pab--OH, or a
pharmaceutically-acceptable salt thereof.
2. A stable form of EtO.sub.2C--CH.sub.2--(R)Cgl--Aze--Pab--OH, or
a pharmaceutically-acceptable salt thereof.
3. EtO.sub.2C--CH.sub.2--(R)Cgl--Aze--Pab--OH, or a
pharmaceutically-acceptable salt thereof, in a form which has a
high stability.
4. A compound as claimed in any one of claims 1 to 3, which is not
in the form of a salt, and which is in the form of an
anhydrate.
5. A compound as claimed in any one of claims 1 to 4 that contains
no more than 2% (w/w) water.
6. A compound as claimed in claim 4 or claim 5 characterised by a
differential scanning calorimetry curve, at a heating rate of
5.degree. C./min in a closed cup with a pinhole under flowing
nitrogen, exhibiting an endotherm with an extrapolated onset
temperature of about 150.degree. C., a peak temperature of about
151.degree. C., and an associated heat of about 113 J/gram,
followed by an exotherm in the region 190-280.degree. C.; and/or a
X-ray powder diffraction pattern characterized by peaks with
d-values at 12.0, 10.0, 8.2, 7.2, 6.0, 5.5, 5.0, 4.92, 4.85, 4.80,
4.42, 4.22, 4.11, 4.06, 3.99, 3.78, 3.72, 3.62, 3.34, 3.11, 3.10
and 3.03 .ANG..
7. A compound as claimed in claim 4 or claim 5 characterised by a
differential scanning calorimetry curve, at a heating rate of
5.degree. C./min in a closed cup with a pinhole under flowing
nitrogen, exhibiting an endotherm with an extrapolated onset
temperature of about 169.degree. C., a peak temperature of about
170.degree. C., and an associated heat of about 142 J/gram,
followed by an exotherm in the region 180-280.degree. C.; and/or a
X-ray powder diffraction pattern characterized by peaks with
d-values at 12.0, 11.1, 8.8, 7.2, 6.8, 6.6, 6.5, 6.4, 6.0, 5.8,
5.6, 5.3, 5.2, 4.75, 4.52, 4.39, 4.31, 4.29, 4.25, 4.06, 4.00,
3.82, 3.73, 3.71, 3.69, 3.66, 3.59, 3.55, 3.41, 3.37, 3.34, 3.29,
3.25, 3.22, 3.10, 3.03, 3.00, 2.91, 2.78, 2.73, 2.62, 2.51, 2.46,
2.40, 2.38, 2.34, 2.29, 2.26 .ANG..
8. A compound as claimed in any one of claims 1 to 3 which is not
in the form of a salt, and which is in the form of a
monohydrate.
9. A compound as claimed in claim 8, characterised by a
differential scanning calorimetry curve, at a heating rate of
5.degree. C./min in a closed cup with a pinhole under flowing
nitrogen, exhibiting an endotherm with an extrapolated onset
temperature of about 94.degree. C., a peak temperature of about
109.degree. C., and an associated heat of about 171 J/gram,
followed by an exotherm in the region 170-290.degree. C.; and/or a
X-ray powder diffraction pattern characterized by peaks with
d-values at 16.4, 13.7, 9.4, 8.2, 7.1, 6.2, 5.5, 5.1, 4.98, 4.75,
4.68, 4.57, 4.48, 4.27, 4.21, 4.11, 4.04, 3.93, 3.89, 3.83, 3.68,
3.52, 3.47, 3.34, 3.26, 3.02, 2.61 and 2.42 .ANG..
10. A compound as claimed in any one of claims 1 to 3 which is in
the form of a hydrobromide salt.
11. A compound as claimed in claim 10, characterised by a
differential scanning calorimetry curve, at a heating rate of
5.degree. C./min in a closed cup with a pinhole under flowing
nitrogen, exhibiting an endotherm with an extrapolated onset
temperature of about 166.degree. C., a peak temperature of about
167.degree. C., and an associated heat of about 69 J/gram, followed
by an exotherm in the region 170-220.degree. C.; and/or a X-ray
powder diffraction pattern characterized by peaks with d-values at
12.0, 10.1, 9.5, 6.0, 5.7, 5.6, 5.2, 5.1, 4.95, 4.74, 4.57, 4.41,
4.35, 4.17, 4.07, 4.03, 3.92, 3.82, 3.72, 3.69, 3.62, 3.51, 3.48,
3.38, 3.25, 3.06, 2.92, 2.86, 2.71, 2.53 and 2.33 .ANG..
12. A compound as claimed in any one of claims 1 to 3 which is in
the form of a methanesulphonate salt.
13. A compound as claimed in claim 12, characterised by a
differential scanning calorimetry curve, at a heating rate of
5.degree. C./min in a closed cup with a pinhole under flowing
nitrogen, exhibiting an endotherm with an extrapolated onset
temperature of about 134.degree. C., a peak temperature of about
137.degree. C., and an associated heat of about 93 J/gram, followed
by an exotherm in the region 140-220.degree. C.; and/or a X-ray
powder diffraction pattern characterized by peaks with d-values at
12.0, 11.7, 10.4, 10.2, 8.3, 7.8, 6.0, 5.6, 5.5, 5.2, 5.1, 5.0,
4.98, 4.90, 4.75, 4.63, 4.54, 4.46, 4.15, 4.06, 3.92, 3.84, 3.74,
3.65, 3.56, 3.47, 3.39, 3.22, 3.12, 2.95, 2.88, 2.76, 2.74, 2.69,
2.65, 2.54, 2.52, 2.49, 2.27, 2.21, 2.04 and 2.02 .ANG..
14. A process for the production of a compound as claimed in any
one of claims 1 to 13, which comprises crystallising
EtO.sub.2C--CH.sub.2--(R)Cg- l--Aze--Pab--OH, or a pharmaceutically
acceptable salt thereof.
15. A process as claimed in claim 14, which comprises crystallising
EtO.sub.2C--CH.sub.2--(R)Cgl--Aze--Pab--OH, or the salt, from a
solvent.
16. A process as claimed in claim 15, wherein the solvent is
selected from the group: acetates, lower alkyl alcohols, aliphatic
and aromatic hydrocarbons, dialkyl ethers, dialkyl ketones,
acetonitrile, aqueous solvents, or mixtures thereof.
17. A process as claimed in claim 16 wherein the solvent is
selected from the group: C.sub.1-6 alkyl acetates, linear or
branched C.sub.1-6 alkyl alcohols, C.sub.6-12 aliphatic
hydrocarbons, C.sub.6-10 aromatic hydrocarbons, di-C.sub.1-6 alkyl
ethers, di-C.sub.1-6 alkyl ketones, acetonitrile, water, or
mixtures thereof.
18. A process as claimed in claim 17 wherein the solvent is
selected from the group: ethyl acetate, butyl acetate, ethanol,
iso-propanol, iso-octane, n-heptane, toluene, di-iso-propyl ether,
acetone, methyl iso-butyl ketone, acetonitrile, water, or mixtures
thereof.
19. A process for the production of a compound as claimed in any
one of claims 4 to 7, which comprises a process according to any
one of claims 15 to 18, in which the solvent is substantially free
of water.
20. A process for the production of a compound as claimed in any
one of claims 4, 5 or 7, which comprises a process according to any
one of claims 15 to 18, in which the solvent contains water.
21. A process for the production of a compound as claimed in claim
8 or claim 9, which comprises a process according to any one of
claims 15 to 18, in which the solvent contains water.
22. A process for the conversion of one crystalline form of a
compound as claimed in any one of claims 1 to 3 to another which
comprises recrystallising a compound as claimed in any one of
claims 1 to 3 from an appropriate solvent system.
23. A compound obtainable by a process according to any one of
claims 14 to 22.
24. A compound as claimed in any one of claims 1 to 13 or 23 for
use as a pharmaceutical.
25. A compound as claimed in any one of claims 1 to 13 or 23 for
use as a prodrug.
26. A pharmaceutical formulation including a compound as defined in
any one of claims 1 to 13 or 23 in admixture with a
pharmaceutically acceptable adjuvant, diluent or carrier.
27. The use of compound as defined in any one of claims 1 to 13 or
23 for the manufacture of a medicament for the treatment of a
condition where inhibition of thrombin is required or desired.
28. A method of treatment of a condition where inhibition of
thrombin is required or desired which method comprises
administering a therapeutically effective amount of a compound
according to any one of claims 1 to 13 or 23 to a patient in need
of such treatment.
Description
FIELD OF THE INVENTION
[0001] This invention relates to new solid state forms of a drug,
to pharmaceutical compositions containing them, and to processes
for obtaining them.
BACKGROUND OF THE INVENTION
[0002] In the formulation of drug compositions, it is important for
the drug substance to be in a form in which it can be conveniently
handled and processed. This is of importance, not only from the
point of view of obtaining a commercially viable manufacturing
process, but also from the point of view of subsequent manufacture
of pharmaceutical formulations (e.g. oral dosage forms such as
tablets) comprising the active compound.
[0003] Further, in the manufacture of oral drug compositions, it is
important that a reliable, reproducible and constant plasma
concentration profile of drug is provided following administration
to a patient. This is of particular importance in the manufacture
of compositions comprising antithrombotic agents.
[0004] Chemical stability, solid state stability, and "shelf life"
of the active ingredients are also very important factors. The drug
substance, and compositions containing it, should be capable of
being effectively stored over appreciable periods of time, without
exhibiting a significant change in the active component's
physico-chemical characteristics (e.g. its chemical composition,
density, hygroscopicity and solubility).
[0005] Moreover, it is also important to be able to provide drug in
a form which is as chemically-pure as possible.
[0006] Amorphous materials may present significant problems in this
regard. For example, such materials are typically difficult to
handle and to formulate, provide for unreliable solubility, and are
often found to be unstable and chemically impure.
[0007] The skilled person will appreciate that, if a drug can be
readily obtained in a stable crystalline form, the above problems
may be solved.
[0008] Thus, in the manufacture of commercially viable, and
pharmaceutically acceptable, drug compositions, it is important,
wherever possible, to provide drug in a substantially crystalline,
and stable, form.
[0009] It is to be noted, however, that this goal is not always
achievable. Indeed, typically, it is not possible to predict, from
molecular structure alone, what the crystallisation behaviour of a
compound, either as such or in the form of a salt, will be. This
can only be determined empirically.
PRIOR ART
[0010] International patent application WO 97/23499 discloses a
number of compounds, which have been found to be useful as prodrugs
of thrombin inhibitors, which thrombin inhibitors are of the
general formula:
R.sup.aO.sub.2C--CH.sub.2--(R)Cgl--Aze--Pab--H
[0011] wherein R.sup.a represents H, benzyl or C.sub.1-6 alkyl, Cgl
represents cyclohexylglycine, Aze represents
S-azetidine-2-carboxylic acid and Pab--H represents
4-aminomethyl-amidinobenzene. The active thrombin inhibitors are
themselves disclosed in the earlier international patent
application WO 94/29336.
[0012] WO 97/23499 also contains a specific disclosure of the
compound:
EtO.sub.2C--CH.sub.2--(R)Cgl--Aze--Pab--OH
[0013] wherein Pab--OH represents 4aminomethyl-benzeneamidoxime. A
process for the synthesis of this compound is described in Example
17 of WO 97/23499, where it is purified by preparative RPLC and
isolated in an amorphous form.
[0014] Whether it is possible to provide
EtO.sub.2C--CH.sub.2--(R)Cgl--Aze- --Pab--OH in a crystalline form
is not disclosed in WO 97/23499. Furthermore, no information is
provided in relation to how this compound may be obtained in such a
form.
DISCLOSURE OF THE INVENTION
[0015] Surprisingly, we have found that
EtO.sub.2C--CH.sub.2--(R)Cgl--Aze-- -Pab--OH may be obtained in one
or more forms that are substantially crystalline in nature.
[0016] Thus, according to a first aspect of the invention there is
provided EtO.sub.2C--CH.sub.2--(R)Cgl--Aze--Pab--OH, or a
pharmaceutically-acceptable salt thereof, in a substantially
crystalline form (hereinafter referred to as "the compounds of the
invention").
[0017] Although we have found that it is possible to produce
EtO.sub.2C--CH.sub.2--(R)Cgl--Aze--Pab--OH, and salts thereof, in
forms which are greater than 80% crystalline, by "substantially
crystalline" we include greater than 10% (e.g. greater that 20%),
preferably greater then 30%, and more preferably greater than 40%
crystalline. The degree (%) of crystallinity may be determined by
the skilled person using X-ray powder diffraction (XRPD). Other
techniques, such as solid state NMR, FT-IR, Raman spectroscopy,
differential scanning calorimetry (DSC) and microcalorimetry, may
also be used.
[0018] Suitable pharmaceutically-acceptable salts which may be
mentioned include inorganic, and organic, acidic and basic addition
salts, such as hydrogen halide salts (e.g. HBr salts), carboxylic
acid salts, lower alkanesulphonate salts (e.g. linear or branched
C.sub.1-6 alkanesulphonate, preferably C.sub.1-3 alkanesulphonate,
and especially ethane- and methanesulphonate salts) and ammonium
and amine salts. Toluenesulphonate salts may also be mentioned. For
a full list of salts that may be mentioned see Berge et al, J.
Pharm. Sci., 66, 1 (1977). However, we prefer that the compounds of
the invention are not in the form of a salt.
[0019] The compounds of the invention may be in the form of a
solvate (by which we include a hydrate) or otherwise.
[0020] We have found, surprisingly, that the compounds of the
invention have an improved stability when compared with
EtO.sub.2C--CH.sub.2--(R)Cg- l--Aze--Pab--OH prepared as described
in WO 97/23499.
[0021] According to a further aspect of the invention, there is
thus provided a stable form of
EtO.sub.2C--CH.sub.2--(R)Cgl--Aze--Pab--OH, or a
pharmaceutically-acceptable salt thereof.
[0022] The term "stability" as defined herein includes chemical
stability and solid state stability. By "chemical stability", we
include that the compound, or salt, can be stored in an isolated
form, or in the form of a formulation in which it is provided in
admixture with pharmaceutically acceptable carriers, diluents or
adjuvants (e.g. in an oral dosage form, such as tablet, capsule
etc.), under normal storage conditions, with an insignificant
degree of chemical degradation or decomposition.
[0023] By "solid state stability", we include that the compound, or
salt, can be stored in an isolated solid form, or in the form of a
solid formulation in which it is provided in admixture with
pharmaceutically acceptable carriers, diluents or adjuvants (e.g.
in an oral dosage form, such as tablet, capsule etc.), under normal
storage conditions, with an insignificant degree of solid state
transformation (e.g. crystallisation, recrystallisation, solid
state phase transition, hydration, dehydration, solvatisation or
desolvatisation).
[0024] Examples of "normal storage conditions" include temperatures
of between minus 80 and plus 50.degree. C. (preferably between 0
and 40.degree. C. and more preferably room temperatures, such as 15
to 30.degree. C.), pressures of between 0.1 and 2 bars (preferably
at atmospheric pressure), relative humidities of between 5 and 95%
(preferably 10 to 75%), and/or exposure to 460 lux of UV/visible
light, for prolonged periods (i.e. greater than or equal to six
months). Under such conditions, compounds of the invention may be
found to be less than 15%, more preferably less than 10%, and
especially less than 5%, chemically degraded/decomposed, or solid
state transformed, as appropriate. The skilled person will
appreciate that the above-mentioned upper and lower limits for
temperature, pressure and relative humidity represent extremes of
normal storage conditions, and that certain combinations of these
extremes will not be experienced during normal storage (e.g. a
temperature of 50.degree. C. and a pressure of 0.1 bar).
[0025] The compounds of the invention may be obtained
advantageously by crystallising
EtO.sub.2C--CH.sub.2--(R)Cgl--Aze--Pab--OH, or a salt of
EtO.sub.2C--CH.sub.2--(R)Cgl--Aze--Pab--OH.
[0026] According to a further aspect of the invention, there is
provided a process for the production of a compound of the
invention which comprises crystallising
EtO.sub.2C--CH.sub.2--(R)Cgl--Aze--Pab--OH, or a
pharmaceutically-acceptable salt thereof.
[0027] It is possible to crystallise
EtO.sub.2C--CH.sub.2--(R)Cgl--Aze--Pa- b--OH and
pharmaceutically-acceptable salts thereof with or without the
presence of a solvent system (e.g. crystallisation may be from a
melt, under supercritical conditions, or achieved by sublimation).
However, we prefer that the crystallisation is from an appropriate
solvent system.
[0028] We have found that it is possible advantageously to
crystallise EtO.sub.2C--CH.sub.2--(R)Cgl--Aze--Pab--OH and
pharmaceutically-acceptabl- e salts thereof via crystallisation
following dissolution of the compound or salt in question, or, more
advantageously, from solutions which have been extracted from
reaction solutions in which the compound or salt in question has
been formed, or, particularly advantageously, from reaction
solutions within which the compound or salt in question has been
formed.
[0029] The solvent system may be heterogeneous or homogeneous and
may thus comprise one or more organic solvents, such as alkyl
acetates (e.g. linear or branched C.sub.1-6 alkyl acetates, such as
ethyl acetate, iso-propyl acetate and butyl acetate), lower (e.g.
linear or branched C.sub.1-6) alkyl alcohols (e.g. ethanol,
iso-propanol), aliphatic (e.g. C.sub.6-12, such as C.sub.7-12,
aliphatic) hydrocarbons (e.g. iso-octane and n-heptane) and
aromatic hydrocarbons (e.g. toluene), dialkyl ketones (e.g.
acetone, methyl iso-butyl ketone), acetonitrile and dialkyl ethers
(e.g. di-iso-propyl ether), and/or aqueous solvents, such as water.
Mixtures of any of the above-mentioned solvents may be used.
[0030] Different crystalline forms may have different solubilities
in different organic solvents at any given temperature. In this
respect, above-mentioned solvents may be employed as "antisolvents"
(i.e. a solvent in which compounds of the invention are poorly
soluble), and may thus aid the crystallisation process.
[0031] When the crystallisation takes place from a reaction solvent
in which EtO.sub.2C--CH.sub.2--(R)Cgl--Aze--Pab--OH, or salt
thereof, has been formed, or from a solvent following an
extraction, suitable solvents thus include alkyl acetates (such as
ethyl acetate), toluene, methyl iso-butyl ketone, lower alkyl
alcohols (such as ethanol) etc.
[0032] Crystallisation of compounds of the invention from an
appropriate solvent system may be achieved by attaining
supersaturation in a solvent system which comprises
EtO.sub.2C--CH.sub.2--(R)Cgl--Aze--Pab--OH, or salt thereof, (e.g.
by cooling, by solvent evaporation and/or via the addition of
anti-solvent (i.e. a solvent in which the compounds of the
invention are poorly soluble (e.g. iso-octane, n-heptane,
di-iso-propyl ether, toluene, acetone))), or by decreasing the
solubility of the substance by the addition of a salt (such as NaCl
or triethylamine.HCl).
[0033] Crystallisation temperatures and crystallisation times
depend upon the concentration of the compound in solution, and upon
the solvent system which is used.
[0034] Crystallisation may also be initiated and/or effected with
or without seeding with crystals of the appropriate crystalline
compound of the invention, and/or by adjustment of pH.
[0035] Compounds of the invention may be prepared in the form of a
solvate (by which we include in the form of a hydrate, such as a
monohydrate) or otherwise (e.g. in the form of an anhydrate). (The
term "anhydrate", when used in this context, also includes
"ansolvates".)
[0036] To ensure that anhydrate is produced, the solvent from which
the crystallisation occurs should preferably be dried, either
before or during the crystallisation process, in order to reduce
the water content below a critical level, which should preferably
not be exceeded during the crystallisation. Solvent may be dried
during the crystallisation process, for example by decreasing the
water content of a mixture of the compound to be crystallised and
an appropriate organic solvent/aqueous solvent system (e.g. by
increasing the amount of organic solvent that is present and/or
removal of water by formation of an azeotrope, with successive
distillations). Nonetheless, we have found that, for certain
compounds of the invention that are anhydrates, such solvent drying
is not necessary to ensure formation.
[0037] To ensure that monohydrate is produced, water must be
present in the solvent from which the crystallisation occurs. The
water content should preferably be kept above the critical level
mentioned above during the crystallisation.
[0038] The "critical level" of water depends upon factors such as
temperature, concentration in solution of the compound to be
crystallised, impurity profile, and the solvent system which is
employed, but may be determined non-inventively.
[0039] Thus, according to a further aspect of the invention, there
is provided a compound of the invention which is in the form of an
anhydrate, and a compound of the invention which is in the form of
a monohydrate.
[0040] Crystalline anhydrate may be prepared by crystallising
EtO.sub.2C--CH.sub.2--(R)Cgl--Aze--Pab--OH from one or more organic
solvents (such as ethyl acetate, butyl acetate, acetone, ethanol,
iso-propanol, iso-octane, di-isopropyl ether), water or mixtures
thereof, which may have been dried, and/or may be dried during the
crystallisation process, such that the water content is below the
above-mentioned critical level. Thus, anhydrate may be produced by
crystallisation from a solvent system which is substantially free
of water.
[0041] By "substantially free of water", we include that the water
content in the solvent system is below that which will result in
the formation of, at most, 10% monohydrate, for any particular
solvent system and set of crystallisation conditions.
[0042] Conversely, crystalline monohydrate may be prepared by
crystallising EtO.sub.2C--CH.sub.2--(R)Cgl--Aze--Pab--OH from a
solvent system comprising water, or a combination of water and one
or more organic solvents, including organic solvents that are
capable of dissolving water (e.g. ethyl acetate, ethanol,
iso-propanol).
[0043] Crystalline monohydrate may also be obtained by dissolving
the substance in an aqueous solution (e.g. water or mixtures of
water and an alcohol, such as ethanol or iso-propanol) with a low
pH followed by the addition of a weak base until the pH exceeds
(and is preferably just above) a value of about 5 to 6 (at room
temperature).
[0044] Crystalline monohydrate may also be prepared via other
crystalline forms (such as an anhydrous form). This is achieved if
the critical water content referred to above is exceeded during the
crystallisation. Similarly, a crystalline anhydrate may be prepared
from crystalline monohydrate by lowering the water content to below
the above-mentioned critical water content during the
crystallisation process.
[0045] Whether anhydrate or monohydrate crystallises is related to
the kinetics and equilibrium conditions of the respective forms at
the specific conditions. Thus, as may be appreciated by the skilled
person, the crystalline form that is obtained depends upon both the
kinetics and the thermodynamics of the crystallisation process.
Under certain thermodynamic conditions (solvent system,
temperature, pressure and concentration of compound of the
invention), one crystalline form may be more stable than another
(or indeed any other). However, crystalline forms that have a
relatively low thermodynamic stability may be kinetically favoured.
Thus, in addition, kinetic factors, such as time, impurity profile,
agitation, the presence or absence of seeds, etc. may also
influence which forms appear. Thus, the procedures discussed herein
may be adapted by the skilled person as appropriate in order to
obtain different crystalline forms.
[0046] Crystalline monohydrate may also be formed by elutriation of
other crystalline forms (e.g. an anhydrous form) in water or a
mixture of water and one or several organic solvents (such as
ethanol or iso-propanol). The slurry which is formed should
preferably be seeded with crystals of the crystalline monohydrate
in order to ensure that an appropriate transformation takes place.
As before, there is a critical water content, which depends on the
solvent system which is employed and the temperature.
[0047] Thus, we have found that compounds of the invention in one
crystalline form may be interconverted via recrystallisation to
other crystalline forms.
[0048] According to a further aspect of the invention, there is
provided a process for the conversion of one crystalline form of a
compound of the invention to another which comprises
recrystallising a compound of the invention from an appropriate
solvent system.
[0049] Compounds of the invention that are anhydrates contain no
more than 3%, preferably 2%, more preferably 1% and more preferably
0.5% (w/w) water, whether such water is bound (crystal water or
otherwise) or not. Hydrates contain no less than 0.5 mol of water
per mol of EtO.sub.2C--CH.sub.2--(R)Cgl--Aze--Pab--OH.
[0050] Preferred compounds of the invention are those that are in
the form of an anhydrate. According to a further aspect of the
invention, there is provided a compound of the invention that
contains no more than 3% (w/w), preferably no more than 2% (w/w),
water, whether such water is bound (crystal water or otherwise) or
not.
[0051] When the compound of the invention is to be produced in the
form of an acidic or basic addition salt, an appropriate amount of
the appropriate acid or base may be added to the crystallisation
mixture before crystallisation is effected. Alternatively, after
addition of the salt, all of the solvent(s) may be evaporated and
the resultant crystalline and/or amorphous form of the salt may be
re-dissolved in an appropriate solvent system, such as ethyl
formate or an alkyl alcohol such as n-heptanol or n-octanol,
followed by agitation of the resultant solution with a view to
inducing crystallisation.
[0052] Preferred addition salts include acidic addition salts, such
as hydrobromide and methanesulphonate salts.
[0053] The preparation, and characterisation, of inter alia
anhydrate, and monohydrate, forms of compounds of the invention are
described hereinafter. Different crystalline forms of the compounds
of the invention (e.g. anhydrate and monohydrate) may be readily
characterised using X-ray powder diffraction (XRPD) methods, for
example as described hereinafter.
[0054] In order to ensure that crystalline forms as described
herein are prepared in the absence of other crystalline forms
described herein, crystallisations are preferably carried out by
seeding with nuclei and/or seed crystals of the desired crystalline
form in the complete absence of nuclei and/or seed crystals of
other crystalline forms described herein. This applies particularly
to each of the specific crystalline forms, the preparation of which
is described hereinafter in the Examples.
[0055] Compounds of the invention may be isolated using techniques
which are well known to those skilled in the art, for example
decanting, filtering or centrifuging.
[0056] Compounds may be dried using standard techniques. It will be
appreciated by the skilled person that drying temperature and
drying time may affect the solid state properties of compounds (or
salts) that are in the form of solvates, such as hydrates (e.g.
dehydration may occur at elevated temperatures and/or reduced
pressure). For example, following the formation of crystalline
monohydrate, there is a critical humidity below which the drying
should not be performed, as the crystal water may be lost and a
solid state transformation may occur, i.e. the crystal water will
be lost if the crystals are dried at high temperatures or at very
low pressures for a longer period.
[0057] We have found that, by employing the crystallisation process
as described herein, it is possible to produce compounds of the
invention with a chemical purity which is above that of the
EtO.sub.2C--CH.sub.2--(- R)Cgl--Aze--Pab--OH, or salt, which is to
be isolated in the first instance.
[0058] Further purification of compounds of the invention may be
effected using techniques which are well known to those skilled in
the art. For example impurities may be removed by way of
recrystallisation from an appropriate solvent system (e.g. ethyl
acetate, iso-propanol, iso-octane, ethanol, water or a combination
of these solvents). Suitable temperatures and times for the
recrystallisation depend upon the concentration of the compound, or
salt, in solution, and upon the solvent system which is used.
[0059] When compounds of the invention are crystallised, or
recrystallised, as described herein, the resultant compound, or
salt, is in a form which has the improved chemical and solid state
stability mentioned hereinbefore.
Pharmaceutical Preparations and Medical Uses
[0060] In accordance with the invention, the compounds of the
invention may be administered orally, intravenously,
subcutaneously, buccally, rectally, dermally, nasally, tracheally,
bronchially, by any other parenteral route, or via inhalation, in
the form of a pharmaceutical preparation comprising the compound of
the invention in a pharmaceutically acceptable dosage form. However
we prefer that the compound of the invention is a form which is
suitable for oral administration.
[0061] Depending on the disorder, and the patient to be treated, as
well as the route of administration, the compounds may be
administered at varying doses (see below).
[0062] The compounds of the invention may be further processed
before formulation into a suitable pharmaceutical formulation. For
example, the crystalline form may be milled or ground into smaller
particles.
[0063] According to a further aspect of the invention, there is
provided a pharmaceutical formulation including a compound of the
invention in admixture with a pharmaceutically acceptable adjuvant,
diluent or carrier.
[0064] The amount of compound of the invention which is employed in
such a formulation will depend on the condition, and patient, to be
treated, as well as the compound(s) which is/are employed, but can
be determined non-inventively.
[0065] The compounds of the invention are useful because they are
metabolised in the body following administration to form compounds
which possess pharmacological activity. They are therefore
indicated as pharmaceuticals, and in particular as prodrugs of
pharmacologically-activ- e compounds.
[0066] In particular, the compounds of the invention, although
inactive to thrombin per se, are metabolised in the body to form
potent inhibitors of thrombin, for example as demonstrated in the
tests described in WO 97/23499. The compounds of the invention are
expected to be useful in the treatment of conditions where
inhibition of thrombin is required or desirable, including those
described in WO 97/23499, the disclosure in which document is
hereby incorporated by reference.
[0067] Suitable doses of the compound of the invention in the
therapeutic and/or prophylactic treatment of mammalian, especially
human, patients are in the range 2 to 200 mg per day at peroral
administration, and 1 to 100 mg per day at parenteral
administration and/or 0.001 to 20 mg/kg, preferably 0.01 to 5
mg/kg, body weight per day at peroral administration and 0.0005 to
10 mg/kg, preferably 0.005 to 2.5 mg/kg, body weight at parenteral
administration.
[0068] According to a further aspect of the invention there is
provided a method of treatment of a condition where inhibition of
thrombin is required or desired, which method includes
administering a therapeutically effective amount of a compound of
the invention to a patient in need of such treatment.
[0069] For the avoidance of doubt, by "treatment" we include the
therapeutic treatment, as well as the prophylaxis, of a
condition.
[0070] The compounds of the invention have the advantage that they
are in a form which provides for improved ease of handling.
Further, the compounds of the invention have the advantage that
they may be produced in forms which have improved chemical and
solid state stability (including lower hygroscopicity). Thus, the
compounds may be stable when stored over prolonged periods.
[0071] Compounds of the invention may also have the advantage that
they may be crystallised in good yields, in a higher purity, in
less time, more conveniently, and at a lower cost, than forms of
EtO.sub.2C--CH.sub.2--(R)Cgl--Aze--Pab--OH prepared previously.
[0072] The invention is illustrated, but in no way limited, by the
following examples, with reference to the enclosed figures in
which:
[0073] FIG. 1 shows a X-ray powder diffractogram for the
crystalline form of EtO.sub.2C--CH.sub.2--(R)Cgl--Aze--Pab--OH
obtained by way of Example 1.
[0074] FIG. 2 shows a X-ray powder diffractogram for the
crystalline form of EtO.sub.2C--CH.sub.2--(R)Cgl--Aze--Pab--OH
monohydrate obtained by way of Example 6.
[0075] FIG. 3 shows a X-ray powder diffractogram for the
crystalline form of EtO.sub.2C--CH.sub.2--(R)Cgl--Aze--Pab--OH
hydrobromide obtained by way of Example 9.
[0076] FIG. 4 shows a X-ray powder diffractogram for the
crystalline form of EtO.sub.2C--CH.sub.2--(R)Cgl--Aze--Pab--OH
methanesulphonate obtained by way of Example 12.
[0077] FIG. 5 shows a X-ray powder diffractogram for the
crystalline form of EtO.sub.2C--CH.sub.2--(R)Cgl--Aze--Pab--OH
obtained by way of Example 14.
GENERAL PROCEDURES
[0078] X-ray powder diffraction analysis (XRPD) was performed on
samples prepared according to standard methods, for example those
described in Giacovazzo, C. et al (1995), Fundamentals of
Crystallography, Oxford University Press; Jenkins, R. and Snyder,
R. L. (1996), Introduction to X-Ray Powder Diractometry, John Wiley
& Sons, New York; Bunn, C. W. (1948), Chemical Crystallography,
Clarendon Press, London; or Klug, H. P. & Alexander, L. E.
(1974), X-ray Diffraction Procedures, John Wiley and Sons, New
York. X-ray analyses were performed using a Siemens D5000
diffractometer and/or a Philips X'Pert MPD.
[0079] Differential scanning calorimetry (DSC) was performed using
a Mettler DSC820 instrument, according to standard methods, for
example those described in Hohne, G. W. H. et al (1996),
Differential Scanning Calorimetry, Springer, Berlin.
[0080] Thermogravimetric analysis (TGA) was performed using a
Mettler Toledo TGA850 instrument.
[0081] Forms prepared in accordance with the Examples below showed
"essentially" the same XRPD diffraction patterns and/or DSC and/or
TGA thermograms as other Examples disclosed below, when it was
clear from the relevant patterns/thermograms (allowing for
experimental error) that the same crystalline form had been formed.
Thus, DSC onset temperatures may vary in the range .+-.5.degree. C.
(e.g. .+-.2.degree. C.), and XRPD distance values may vary in the
range .+-.2 on the last decimal place.
EXAMPLE 1
Crystallisation of EtO.sub.2C--CH.sub.2--(R)Cgl--Aze--Pab--OH
[0082] 200 mg of EtO.sub.2C--CH.sub.2--(R)Cgl--Aze--Pab--OH
(amorphous; obtained by freeze drying product obtained according to
the method described in Example 17 of International Patent
Application WO 97/23499) was dissolved in a
di-iso-propylether:iso-propanol mixture (14 mL; 1:1). A homogeneous
solution was initially formed which was allowed to stand for 24
hours at room temperature. Filtration and drying (ambient
temperature) gave 160 mg of crystalline product.
[0083] The crystals were analyzed by XRPD and the results are
tabulated below (Table 1, in which RI represents relative
intensity) and are shown in FIG. 1.
1TABLE 1 d-value/.ANG. RI D-value/.ANG. RI D-value/.ANG. RI 12.0 vs
4.42 m 3.10 w 10.0 m 4.22 w 3.03 w 8.2 s 4.11 m 7.2 m 4.06 m 6.0 m
3.99 m 5.5 m 3.78 w 5.0 m 3.72 m 4.92 s 3.62 m 4.85 s 3.34 w 4.80 m
3.11 w
[0084] A unit cell was determined from single crystal X-ray data.
It was triclinic, with P1 symmetry, Z=1, and the following
dimensions: a=5.149(1) .ANG., b=10.466(1) .ANG., c=12.317(1) .ANG.,
.alpha.=80.32(1).degree., .beta.=79.78(1).degree.,
.gamma.=75.57(1).degree., and V=627.2(2) .ANG..sup.3.
[0085] DSC showed an endotherm with an extrapolated onset
temperature of ca. 150.degree. C. (ca. 113 J/g). TGA showed a
decrease in mass of ca. 0.6% (w/w) around 150.degree. C.
EXAMPLE 2
Preparation of Crystalline
EtO.sub.2C--CH.sub.2--(R)Cgl--Aze--Pab--OH from an Extracted
Solution
[0086] 70 mL of ethyl acetate was charged into a 140.3 g extracted
solution of EtO.sub.2C--CH.sub.2--(R)Cgl--Aze--Pab--OH (prepared
following an analogous synthesis to the procedure described in WO
97/23499, using ethanol as solvent, quenching with acetone,
concentrating the resultant solution, and extracting with ethyl
acetate). The solution thus prepared comprised ethyl acetate,
ethanol and water (8.7% w/w). The solution was concentrated and
dried by successive distillations, performed at 250 mbar and a bath
temperature of 60.degree. C. 70 mL of ethyl acetate was charged
into the initial solution, which was concentrated until 46 g of
solution remained. 103 mL of ethyl acetate was then charged into
the solution, which was again concentrated until 70.5 g remained.
Seeds of crystals obtained analogously to the method described in
Example 3 were added and the resultant suspension was agitated for
3 hours at 40.degree. C., cooled to 20.degree. C. for 5 hours, then
to 5.degree. C. for 2.5 hours, and finally to -5.degree. C. for 1
hour. The slurry was then agitated at the final temperature
overnight and the crystals were filtered off, washed with ethyl
acetate and dried at 40.degree. C. under reduced pressure
overnight.
[0087] The crystals were analyzed by XRPD, DSC and TGA, and showed
essentially the same diffraction pattern, onset temperature, and
decrease in mass, as those exhibited by the form obtained according
to Example 1 above.
Recrystallisation of EtO.sub.2C--CH.sub.2--(R)Cgl--Aze--Pab--OH
EXAMPLE 3
[0088] 3.0 g EtO.sub.2C--CH.sub.2--(R)Cgl--Aze--Pab--OH (crude;
obtained according to the method described in Example 2 above) was
dissolved in 49.5 mL of iso-propanol and 4.5 mL of purified water
at 60.degree. C. The solution was concentrated and dried by
successive distillations, performed at 100 mbar and a bath
temperature of 60.degree. C. The solution was initially
concentrated, until 17.5 g remained. 30 mL of iso-propanol was then
charged into the resultant, and the solution was concentrated until
20 g remained. 1.8 g of iso-propanol and seeds of crystalline
EtO.sub.2C--CH.sub.2--(R)Cgl--Aze--Pab--OH (obtained via a process
that was analogous to the method described in Example 5 below) were
then charged into the solution. The suspension was agitated for 3
hours at 40.degree. C., and then cooled to 20.degree. C. for 5
hours, to 5.degree. C. for 2.5 hours, and to -5.degree. C. for 1
hour. The slurry was then agitated at the final temperature
overnight. The crystals were filtered off, washed with iso-propanol
and dried at 40.degree. C. under reduced pressure overnight.
[0089] The crystals were analyzed by XRPD, DSC and TGA, and showed
essentially the same diffraction pattern, onset temperature, and
decrease in mass, as those exhibited by the form obtained according
to Example 1 above.
EXAMPLE 4
[0090] 4.0 g EtO.sub.2C--CH.sub.2--(R)Cgl--Aze--Pab--OH (crude;
obtained according to the method described in Example 2 above) was
dissolved in 2 mL of purified water, 16 mL of ethanol and 45 mL of
ethyl acetate at 55.degree. C. The solution was concentrated and
dried by successive distillations performed at 250 mbar and a bath
temperature of 55.degree. C. The solution was initially
concentrated, until 30 g remained. 32 mL of ethyl acetate was then
charged into the resultant, and the solution was concentrated until
28 g remained. An additional 16 mL of ethyl acetate was added and
the solution concentrated until 33 g remained. Seeds of crystalline
EtO.sub.2C--CH.sub.2--(R)Cgl--Aze--Pab--OH (obtained via Example 3
above) was added to the solution. The suspension was agitated for 3
hours at 40.degree. C., and then cooled to 20.degree. C. for 5
hours, to 5.degree. C. for 2.5 hours, and to -5.degree. C. for 1
hour. The slurry was then agitated at the final temperature
overnight. The crystals were filtered off, washed with ethyl
acetate and dried at 40.degree. C. under reduced pressure
overnight.
[0091] The crystals were analyzed by XRPD, DSC and TGA, and showed
essentially the same diffraction pattern, onset temperature, and
decrease in mass, as those exhibited by the form obtained according
to Example 1 above.
EXAMPLE 5
[0092] 3.0 g EtO.sub.2C--CH.sub.2--(R)Cgl--Aze--Pab--OH (crude;
obtained according to the method described in Example 2 above) was
dissolved in 4.5 mL of purified water and 49.5 mL of iso-propanol
at 55 to 60.degree. C. The solution was concentrated and dried by
successive distillations performed at 100 mbar and a bath
temperature of 60.degree. C. The solution was initially
concentrated until 16 g remained. The solution was agitated at
40.degree. C., 18 mL of iso-octane was then charged into the
resultant, and seeds of crystalline
EtO.sub.2C--CH.sub.2--(R)Cgl--Aze--Pa- b--OH (obtained via Example
3 above) were added to the solution. The suspension was agitated
for 3 hours at 40.degree. C., and then cooled to 15.degree. C. for
6 hours. The slurry was then agitated at the final temperature
overnight. The crystals were filtered off, washed with a mixture of
iso-propanol:iso-octane (1:1) and dried at 40.degree. C. under
reduced pressure overnight.
[0093] The crystals were analyzed by XRPD, DSC and TGA, and showed
essentially the same diffraction pattern, onset temperature, and
decrease in mass, as those exhibited by the form obtained according
to Example 1 above.
Crystallisation of EtO.sub.2C--CH.sub.2--(R)Cgl--Aze--Pab--OH
Monohydrate
EXAMPLE 6
[0094] 3.0 g of EtO.sub.2C--CH.sub.2--(R)Cgl--Aze--Pab--OH (crude;
obtained according to the method described in Example 2 above) was
dissolved in 1.5 mL of purified water, 10.5 mL of ethanol and 36 mL
of ethyl acetate at 55.degree. C. The solution was concentrated by
distillation at 250 mbar and a bath temperature of 55.degree. C.
until 18 g remained. 30 mL of ethyl acetate was then charged into
the solution, which was then concentrated until 21 g remained. 3.7
g of ethyl acetate, 0.9 g purified water and seeds of crystalline
EtO.sub.2C--CH.sub.2--(R)Cg- l--Aze--Pab--OH (obtained via Example
3 above) were added to the solution. The suspension was agitated
for 3 hours at 40.degree. C., and then cooled to 20.degree. C. for
5 hours, to 5.degree. C. for 2.5 hours and to -5.degree. C. for 1
hour. The slurry was then agitated at the final temperature for an
additional day. The crystals were filtered off, washed with ethyl
acetate and dried at 40.degree. C. under reduced pressure (150
mbar) overnight.
[0095] The crystals were analyzed by XRPD and the results are
tabulated below (Table 2, in which RI represents relative
intensity) and are shown in FIG. 2.
[0096] DSC showed an endotherm with an extrapolated onset
temperature of ca. 94.degree. C. (ca. 171 J/g). The crystals were
analysed by Karl-Fischer titration and by TGA. TGA showed a
decrease in mass of ca. 3.5% (w/w) around 85.degree. C.,
corresponding to a monohydrate, and a decomposition starting around
210.degree. C.
2TABLE 2 d-value/.ANG. RI D-value/.ANG. RI D-value/.ANG. RI 16.4 s
4.57 m 3.47 w 13.7 s 4.48 m 3.34 m 9.4 vs 4.27 s 3.26 w 8.2 w 4.21
w 3.02 w 7.1 m 4.11 m 2.61 w 6.2 m 4.04 m 2.42 w 5.5 w 3.93 w 5.1 m
3.89 m 4.98 w 3.83 m 4.75 s 3.68 m 4.68 s 3.52 w
EXAMPLE 7
[0097] 5.0 g of EtO.sub.2C--CH.sub.2--(R)Cgl--Aze--Pab--OH (crude;
obtained according to the method described in Example 2 above) was
dissolved in 45 mL of iso-propanol and 30 mL of purified water at
40.degree. C. The solution was filtered until clear and
concentrated by distillation under reduced pressure at 40.degree.
C. until 45 g remained. The solution was then cooled by 10.degree.
C./hour from 40 to -10.degree. C. The slurry was then agitated for
one day at the final temperature and the crystals filtered off,
washed with iso-propanol and dried at 40.degree. C. under reduced
pressure (150 mbar) overnight.
[0098] The crystals were analyzed by XRPD, DSC and TGA, and showed
essentially the same diffraction pattern, onset temperature, and
decrease in mass, as those exhibited by the form obtained according
to Example 6 above.
EXAMPLE 8
[0099] 2.7 g of EtO.sub.2C--CH.sub.2--(R)Cgl--Aze--Pab--OH (crude;
obtained according to the method described in Example 2 above) was
dissolved at 70.degree. C. in 20 mL of ethanol and 30 mL of
purified water. The solution was agitated and seeded with crystals
of EtO.sub.2C--CH.sub.2--(R)Cgl--Aze--Pab--OH (obtained analogously
to the method described in Example 6 above). The ethanol was slowly
evaporated over two days. The crystals were filtered off and dried
at 40.degree. C. (200 mbar) over the weekend.
[0100] The crystals were analyzed by XRPD, DSC and TGA, and showed
essentially the same diffraction pattern, onset temperature, and
decrease in mass, as those exhibited by the form obtained according
to Example 6 above.
Preparation of Crystalline
EtO.sub.2C--CH.sub.2--(R)Cgl--Aze--Pab--OH.HBr
EXAMPLE 9
[0101] 7.08 g of EtO.sub.2C--CH.sub.2--(R)Cgl--Aze--Pab--OH (crude;
obtained according to the method described in Example 2 above) was
dissolved in 200 mL of iso-propanol and 2.52 g of 47% HBr at
40.degree. C. The solution was evaporated to dryness at 40.degree.
C. and reduced pressure. An additional 120 mL of iso-propanol was
charged into the resultant residue in order to rid it of its water
content, and the resultant solution was evaporated to dryness. The
amorphous substance was then dissolved in heptanol at ambient
temperature. After some agitation, crystals formed. The slurry was
agitated overnight, the crystals filtered off, washed with heptanol
and dried at 80.degree. C. under reduced pressure overnight.
[0102] The crystals were analyzed by titration with 0.1M NaOH and
titration with 0.1M AgNO.sub.3. The concentration of substance
according to the titration with NaOH was 96.6% (w/w). The amount of
Br according to the AgNO.sub.3 titration was 13.9% (w/w) which is
indicative, assuming a mono HBr salt, of a salt concentration of
96.4% (w/w). The remainder was solvent residue.
[0103] The crystals were analyzed by XRPD and the results are
tabulated below (Table 3, in which RI represents relative
intensity) and are shown in FIG. 3.
3TABLE 3 d-value/.ANG. RI D-value/.ANG. RI D-value/.ANG. RI 12.0 vs
4.35 m 3.25 w 10.1 s 4.17 w 3.06 w 9.5 m 4.07 m 2.92 w 6.0 m 4.03 m
2.86 w 5.7 s 3.92 m 2.71 w 5.6 m 3.82 m 2.53 w 5.2 m 3.72 w 2.33 w
5.1 s 3.69 m 4.95 s 3.62 w 4.74 w 3.51 w 4.57 w 3.48 m 4.41 m 3.38
m
[0104] DSC showed an endotherm with an extrapolated onset
temperature of ca. 166.degree. C. (ca. 69 J/g).
EXAMPLE 10
[0105] 8 g of EtO.sub.2C--CH.sub.2--(R)Cgl--Aze--Pab--OH (crude;
obtained according to the method described in Example 2 above) was
dissolved in 120 mL of iso-propanol and 2.9 g of 47% HBr at 40 to
50.degree. C. The solution was evaporated to dryness, yielding an
amorphous substance, which was dissolved in 1-octanol. The solution
was agitated at ambient temperature and, after a while,
crystallization occurred. The slurry was agitated overnight, the
crystals filtered off, washed with 1-octanol and dried at
80.degree. C. under reduced pressure over the weekend.
[0106] The crystals were analyzed by XRPD and DSC, and showed
essentially the same diffraction pattern, and onset temperature, as
those exhibited by the form obtained according to Example 9
above.
EXAMPLE 11
[0107] 1 g of EtO.sub.2C--CH.sub.2--(R)Cgl--Aze--Pab--OH (crude;
obtained according to the method described in Example 2 above) was
dissolved in 22 mL of iso-propanol and 0.36 g of 47% HBr at
45.degree. C. The solution was filtered until clear and
concentrated by distillation at reduced pressure until 3.85 g
remained. The solution was agitated at 40.degree. C. and 6 mL of
toluene was added slowly. The solution was seeded with crystals of
the HBr salt (obtained analogusly to the method described in
Example 9 above). When the suspension became white, an additional 9
mL of toluene was added. The slurry was agitated and the
temperature was decreased to 20.degree. C. The slurry was agitated
overnight, the crystals filtered off, washed with toluene and dried
at 40.degree. C. under reduced pressure.
[0108] The crystals were analyzed by XRPD and DSC, and showed
essentially the same diffraction pattern, and onset temperature, as
those exhibited by the form obtained according to Example 9
above.
Preparation of Crystalline
EtO.sub.2C--CH.sub.2--(R)Cgl--Aze--Pab--OH.CH.s- ub.3SO.sub.3H
EXAMPLE 12
[0109] 10 g of EtO.sub.2C--CH.sub.2--(R)Cgl--Aze--Pab--OH (crude;
obtained according to the method described in Example 2 above) was
dissolved in 500 mL of iso-propanol and 2.03 g of methanesulphonic
acid (1 eq.) at 50.degree. C. The solution was evaporated to
dryness at 50.degree. C. under reduced pressure resulting in the
formation of an amorphous solid material. 1.5 g of this substance
was dissolved in 15 mL ethyl formate, and the solution was agitated
at ambient temperature overnight. The formed crystals were filtered
off, washed with ethyl formate and dried at 40.degree. C. under
reduced pressure overnight. The crystals were analyzed by titration
with 0.1 M NaOH, a two-phase titration. A concentration (99.9%) was
calculated based on the assumption of formation of the
mono-mesylate.
[0110] The crystals were analyzed by XRPD and the results are
tabulated below (Table 4, in which RI represents relative
intensity) and are shown in FIG. 4.
[0111] DSC showed an endotherm with an extrapolated onset
temperature of ca. 134.degree. C. (ca. 93 J/g).
4TABLE 4 d-value/.ANG. RI D-value/.ANG. RI D-value/.ANG. RI 12.0 s
4.63 m 2.88 m 11.7 vs 4.54 m 2.76 m 10.4 s 4.46 s 2.74 m 10.2 s
4.15 s 2.69 w 8.3 w 4.06 s 2.65 m 7.8 s 3.92 s 2.54 w 6.0 m 3.84 s
2.52 w 5.6 s 3.74 m 2.49 w 5.5 s 3.65 s 2.27 w 5.2 s 3.56 s 2.21 w
5.1 m 3.47 m 2.04 w 5.0 s 3.39 m 2.02 w 4.98 s 3.22 m 4.90 s 3.12 m
4.75 m 2.95 w
EXAMPLE 13
[0112] 3.0 g of the amorphous substance from the first part of
Example 12 above was dissolved in 15 mL octanol. The solution was
agitated at ambient temperature overnight. The formed crystals were
filtered off, washed with octanol and dried at 40.degree. C. under
reduced pressure overnight.
[0113] The crystals were analyzed by XRPD and DSC, and showed
essentially the same diffraction pattern, and onset temperature, as
those exhibited by the form obtained according to Example 12
above.
Preparation of Further Crystalline Form of
EtO.sub.2C--CH.sub.2--(R)Cgl--A- ze--Pab--OH from
EtO.sub.2C--CH.sub.2--(R)Cgl--Aze--NH--CH.sub.2--C.sub.6H-
.sub.4--CN
EXAMPLE 14
[0114] 0.0029 g of EDTA was dissolved in 16.4 g of aqueous
hydroxylamine (50% (w/w)) and 110 mL ethanol, and was then charged
into a jacketed glass reactor which was kept at a temperature of
32.degree. C. 118.5 g of a solution of glycine,
N-[1-cyclohexyl-2-[2-[[[[4-[cyano]phenyl]methyl]am-
ino]carbonyl]-1-azetidinyl]-2-oxoethyl]-, ethyl ester, (S-(R*, S*))
(EtO.sub.2C--CH.sub.2--(R)Cgl--Aze--NH--CH.sub.2--C.sub.6H.sub.4--CN)
in butyl acetate (approx. concentration 36% (w/w)) was charged into
the reactor. After 18 hours agitation, the solution/suspension was
opaque. A sample was withdrawn to check the conversion using HPLC.
The reaction was quenched by adding 14.4 mL acetone, followed by
addition of 307 mL butyl acetate. The jacket temperature was set to
70.degree. C. and the suspension was agitated for 1 hour at a
temperature of 70.degree. C. to dissolve the precipitate. The
temperature of the thermostatic bath was then set to 40.degree. C.
and the solution was agitated for additional 78 hours. Particles
were still present. The precipitate was filtered off. The filtrate
was charged to a jacketed glass reactor and agitated at 40.degree.
C. An extraction program was started. All of the extractions were
carried out at 40.degree. C. 110 mL Na.sub.2CO.sub.3/NaCl (10%/10%
(w/w)) was charged into the reactor, the solution was mixed for
10-20 minutes. Agitation was then stopped, allowing the phases to
separate. The water phase was removed. 12.5 g ethanol and
additional 110 mL of aqueous Na.sub.2CO.sub.3/NaCl (10%/10% (w/w))
was added, the solution was agitated for a few minutes and the
phases were then allowed to separate. The water phase was removed,
and 12.5 g ethanol and 110 mL of the aqueous Na.sub.2CO.sub.3/NaCl
(10%/10% (w/w)) solution were added. The resultant solution was
agitated for a few minutes and the two phases were then allowed to
separate. The water phase was removed. 4 g of ethanol and 31 mL of
water were added to the organic phase, which was agitated. The pH
was adjusted to 7 by adding HCl (8% (w/w)). The solution was mixed,
the two phases were allowed to separate and the water phase was
removed. 52.9 g of the extraction solution, which comprised around
4 g of EtO.sub.2C--CH.sub.2--(R)Cgl--Aze--Pab--OH was charged into
a round-bottom flask. 4 mL of a 35:65 (v/v) mixture of butyl
acetate and ethanol was charged to the same flask. Solvent was
evaporated using a rotary evaporator at a pressure of 100-200 mbar,
and a bath temperature of 73.degree. C. until 53.1 g solution
remained. An additional 4 mL of the above solvent mixture was then
added, and more solvent was evaporated until 54.74 g of solution
remained. This procedure was repeated several times: 4 mL was
added, the solution was concentrated by evaporation until 56.02 g
remained, 4 mL was added, the solution was again concentrated until
56.04 g remained, an additional 4 mL was charged, and the solution
was concentrated again until 33.43 g remained. 2.2 g of the
solution was withdrawn for analysis of solvent composition by GC
and water content by Karl Fischer titration. The water content was
1.0% (w/w). 0.34 mL of water was charged into the flask, which was
placed in a thermostatic bath kept at 40.degree. C. The solution
was agitated using a teflon impeller for 3 hours and then cooled to
20.degree. C. over 5 hours, to 5.degree. C. over 2.5 hours and to
-5.degree. C. over one hour. The solution was then agitated for two
hours at -5.degree. C. The solution was still almost clear. The
solution was then cooled to -20.degree. C. over 1.5 hours and
agitated at that temperature for additional 20 hours. A very
viscous white slurry was formed. The crystals were filtered off by
vacuum filtration and then dried overnight at 150 mbar and
40.degree. C.
[0115] The crystals were analysed by GC, XRPD, TGA, DSC and Karl
Fischer titration. The XRPD results are tabulated below (Table 5,
in which RI represents relative intensity) and are shown in FIG.
5.
5TABLE 5 d-value/.ANG. RI D-value/.ANG. RI D-value/.ANG. RI 12.0 s
4.31 w 3.25 w 11.1 vs 4.29 m 3.22 vw 8.8 m 4.25 m 3.10 w 7.2 m 4.06
w 3.03 w 6.8 vw 4.00 vw 3.00 vw 6.6 m 3.82 w 2.91 w 6.5 vw 3.73 w
2.78 w 6.4 vw 3.71 m 2.73 w 6.0 w 3.69 w 2.62 vw 5.8 m 3.66 w 2.51
vw 5.6 w 3.59 m 2.46 w 5.3 m 3.55 w 2.40 w 5.2 s 3.41 w 2.38 w 4.75
m 3.37 w 2.34 vw 4.52 w 3.34 w 2.29 vw 4.39 m 3.29 vw 2.26 vw
[0116] DSC showed an endotherm with an extrapolated onset
temperature of ca. 169.degree. C. (ca. 142 J/g). TGA showed a
decrease in mass of ca. 0.7% (w/w) around 170.degree. C.
[0117] A unit cell was determined from single crystal X-ray data.
It was orthorhombic, with P2.sub.12.sub.12.sub.1 symmetry, Z=4, and
the following dimensions: a=7.753(1) .ANG., b=14.331(1) .ANG.,
c=22.276(1) .ANG., .alpha.=.beta.=.gamma.=90.degree., and
V=2471.6(4) .ANG..sup.3.
EXAMPLE 15
[0118] To a solution of around 9 g of
EtO.sub.2C--CH.sub.2--(R)Cgl--Aze--N-
H--CH.sub.2--C.sub.6H.sub.4--CN in a mixture of ethyl
acetate/purified water (concentration of solute around 23% (w/v
total), water concentration around 10% (w/w total)), 50 mL of
ethanol was charged. The temperature of the solution was adjusted
to 39.degree. C. and a mixture of 0.61 mg EDTA and 3.62 g
hydroxylamine (aq; 50% (w/w)) was charged into the reactor. After 1
h 50 min, seed crystals of EtO.sub.2C--CH.sub.2--(R)-
Cgl--Aze--Pab--OH anhydrate (prepared analogously to the method
described in Example 14 above) were added. The suspension was
agitated for 21 hours. 3.18 g of acetone was then charged into the
reactor, and the suspension was agitated for an additional 30
minutes. The suspension was then heated to 60.degree. C. over 3
hours. The temperature was kept at 60.degree. C. for 6 hours and
then cooled by decreasing the jacket temperature by 10.degree. C./h
until the temperature was close to -10.degree. C. The crystals were
then aged for an additional 2 hours. The crystals were separated
from the mother liquor by filtration, washed with 20 mL, followed
by a further 10 mL, of ethanol and then dried at 40.degree. C.
under reduced pressure.
[0119] The crystals were analysed by XRPD, DSC and TGA. The
analyses showed essentially the same XRPD pattern, DSC thermogram,
and decrease in mass, as those exhibited by the form obtained
according to Example 14 above.
EXAMPLE 16
[0120] To a solution of around 4.5 g of
EtO.sub.2C--CH.sub.2--(R)Cgl--Aze--
-NH--CH.sub.2--C.sub.6H.sub.4--CN in a mixture of ethyl
acetate/purified water (concentration of solute around 24% (w/v
total), water concentration around 10% (w/w total)), 9 mL of ethyl
acetate and 11.2 mL of ethanol were charged. The temperature of the
solution was adjusted to 41.degree. C. and a mixture of 0.3 mg EDTA
and 1.78 g of hydroxylamine (aq; 50% (w/w)) was charged into the
round bottom flask. After 1 h 40 min, seed crystals of
EtO.sub.2C--CH.sub.2--(R)Cgl--Aze--Pab--OH anhydrate (prepared
analogously to the method described in Example 14 above) were
added. The suspension was agitated for 22 hours. 2.79 g of acetone
was then charged to the round bottom flask and the suspension was
agitated for additional 19 hours. The crystals were separated from
the mother liquor by filtration, washed with 2.times.10 mL of
ethanol and then dried at 40.degree. C. under reduced pressure.
[0121] The crystals were analysed by XRPD, DSC and TGA. The
analyses showed essentially the same XRPD pattern, DSC thermogram,
and decrease in mass, as those exhibited by the form obtained
according to Example 14 above.
EXAMPLE 17
[0122] To a solution of around 30 kg of
EtO.sub.2C--CH.sub.2--(R)Cgl--Aze--
-NH--CH.sub.2--C.sub.6H.sub.4--CN in 130 L of a mixture of ethyl
acetate/water, 151 kg of ethanol was charged. The temperature of
the solution was adjusted to 38.degree. C. and a mixture of 2.1 g
EDTA and 12.0 kg hydroxylamine (aq.; 51% (w/w)) was charged into
the reactor. After around 1.5 to 2 hours, 171 g of seed crystals of
EtO.sub.2C--CH.sub.2--(R)Cgl--Aze--Pab--OH anhydrate (prepared
analogously to the method described in Example 14 above) were
added. The suspension was agitated for around 23 hours. 19 kg of
acetone was then charged into the reactor and the suspension was
agitated for an additional 30 minutes. The suspension was then
heated to 73.degree. C. until all of the crystals were dissolved.
The solution was cooled by decreasing the jacket temperature by
10.degree. C./h. When the temperature was around 61.degree. C., a
further 172 g of the same seed crystals were added, and the cooling
was continued until the temperature was close to -10.degree. C. The
crystals were then aged for an additional 11 hours. The crystals
were separated from the mother liquor by centrifugation, washed
with 90 kg iso-propanol and then dried at 40.degree. C. under
reduced pressure.
[0123] The crystals were analysed by XRPD, DSC and TGA. The
analyses showed essentially the same XRPD pattern, DSC thermogram,
and decrease in mass, as those exhibited by the form obtained
according to Example 14 above.
EXAMPLE 18
[0124] To a solution of around 5 g of
EtO.sub.2C--CH.sub.2--(R)Cgl--Aze--N-
H--CH.sub.2--C.sub.6H.sub.4--CN in an ethyl acetate/water mixture
(concentration of solute around 26% (w/v total), water
concentration around 10% (w/w total)), 12.5 mL of ethanol was
charged. The temperature of the solution was adjusted to 41.degree.
C. and a mixture of 0.3 mg of EDTA and 7.49 g of hydroxylamine (aq;
50% (w/w)) were charged into the round bottom flask. After 1 h 40
min, seed crystals of EtO.sub.2C--CH.sub.2--(R)Cgl--Aze--Pab--OH
anhydrate (prepared analogously to the method described in Example
14 above) were added. The suspension was agitated for 22 hours.
2.79 g of acetone was then charged into the round bottom flask and
the suspension was agitated for an additional 19 hours. The
crystals were separated from the mother liquor by filtration,
washed with 2.times.10 mL of ethanol and then dried at 40.degree.
C. under reduced pressure.
[0125] The crystals were analysed by XRPD, DSC and TGA. The
analyses showed essentially the same XRPD pattern, DSC thermogram,
and decrease in mass, as those exhibited by the form obtained
according to Example 14 above.
EXAMPLE 19
[0126] To a solution of around 9 g of
EtO.sub.2C--CH.sub.2--(R)Cgl--Aze--N-
H--CH.sub.2--C.sub.6H.sub.4--CN in a mixture of ethyl
acetate/purified water (concentration of solute around 23% (w/v
total), water concentration around 10% (w/w total)), 56 mL of
ethanol was charged. The temperature of the solution was adjusted
to 50.degree. C. and a mixture of 0.6 mg of EDTA and 3.49 g of
hydroxylamine (aq; 50% (w/w)) was charged into the round bottom
flask. After 1 h 40 min, 50 mg of seed crystals of
EtO.sub.2C--CH.sub.2--(R)Cgl--Aze--Pab--OH anhydrate (prepared
analogously to the method described in Example 14 above) were
added. The suspension was agitated for 18 hours. 3.1 g of acetone
was then charged to the round bottom flask and the suspension was
agitated for additional 30 minutes. The suspension was then heated
to 75.degree. C. over 0.5 hours. 40 minutes later, the temperature
of the bath was lowered to 25.degree. C. (i.e. the crystal
suspension was cooled by natural cooling). 21 hours later, the
crystals were separated from the mother liquor by filtration and
then dried at 40.degree. C. under reduced pressure.
[0127] The crystals were analysed by XRPD, DSC and TGA. The
analyses showed essentially the same XRPD pattern, DSC thermogram,
and decrease in mass, as those exhibited by the form obtained
according to Example 14 above.
Recrystallisation of EtO.sub.2C--CH.sub.2--(R)Cgl--Aze--Pab--OH
obtained analogously to Methods of Examples 14 to 19
EXAMPLE 20
[0128] 2.0 g of crude EtO.sub.2C--CH.sub.2--(R)Cgl--Aze--Pab--OH
(obtained analogously to methods described in Examples 14 to 19
above) was dissolved in a mixture of 13 mL of iso-propanol, 5 mL
purified water and 0.65 g of ethanol at 70.degree. C. The solution
was agitated and cooled from 70 to 55.degree. C. over 1.5 h. 2 mL
of acetone was then added and the cooling was continued from
55.degree. C. to 30.degree. C. over 5 h, and from 30.degree. C. to
0.degree. C. over 3 h. The suspension was then agitated for 340 min
at the final temperature. The crystals were filtered off and washed
with 4 mL of iso-propanol and thereafter dried at 40.degree. C.
under reduced pressure.
[0129] The crystals were analysed by XRPD, DSC and TGA. The
analyses showed essentially the same XRPD pattern, DSC thermogram,
and decrease in mass, as those exhibited by the form obtained
according to Example 14 above.
EXAMPLE 21
[0130] 2.0 g of crude EtO.sub.2C--CH.sub.2--(R)Cgl--Aze--Pab--OH
(obtained analogously to methods described in Examples 14 to 19
above) was dissolved in a mixture of 1.5 mL of iso-propanol, 4.8 mL
of purified water and 0.001 g of sodium hydroxide dissolved in 0.2
mL of purified water at 70.degree. C. The solution was agitated for
1.5 h at 70.degree. C. and thereafter cooled to 0.degree. C. over 7
h. The suspension was agitated for 55 min at the final temperature.
The crystals were filtered off and washed with 5 mL of iso-propanol
and thereafter dried at 40.degree. C. under reduced pressure.
[0131] The crystals were analysed by XRPD, DSC and TGA. The
analyses showed essentially the same XRPD pattern, DSC thermogram,
and decrease in mass, as those exhibited by the form obtained
according to Example 14 above.
EXAMPLE 22
[0132] 1.5 g of crude EtO.sub.2C--CH.sub.2--(R)Cgl--Aze--Pab--OH
(obtained analogously to methods described in Examples 14 to 19
above) was dissolved in a mixture of 10.13 mL of iso-propanol, 3.75
mL of purified water, and 1.13 mL of ethyl acetate at 70.degree. C.
The solution was cooled to 55.degree. C. and thereafter to
0.degree. C. over 5.5 h. The suspension was agitated for 695 min.
at the final temperature. The crystals were filtered off and washed
with 3 mL of iso-propanol and thereafter dried at 40.degree. C.
under reduced pressure.
[0133] The crystals were analysed by XRPD, DSC and TGA. The
analyses showed essentially the same XRPD pattern, DSC thermogram,
and decrease in mass, as those exhibited by the form obtained
according to Example 14 above.
EXAMPLE 23
[0134] 31.0 kg of crude EtO.sub.2C--CH.sub.2--(R)Cgl--Aze--Pab--OH
(obtained analogously to methods described in Examples 14 to 19
above) was dissolved in a mixture of 158 kg of iso-propanol and 78
kg of purified water at 71.degree. C. A further 24 kg of
iso-propanol was added following clear filtration. The solution was
thereafter cooled to 57.degree. C. and crystallisation was started
by adding 78 g of seed crystals (obtained analogously to the method
described in Example 14 above). The suspension was agitated whilst
being cooled by 10.degree. C./h to 0.degree. C. The suspension was
then agitated for 11 h at the final temperature. After
centrifugation of the slurry, the crystals were washed with 84 kg
of iso-propanol and thereafter dried at 40.degree. C. under reduced
pressure.
[0135] The crystals were analysed by XRPD, DSC and TGA. The
analyses showed essentially the same XRPD pattern, DSC thermogram,
and decrease in mass, as those exhibited by the form obtained
according to Example 14 above.
EXAMPLE 24
[0136] 3.0 g of crude EtO.sub.2C--CH.sub.2--(R)Cgl--Aze--Pab--OH
(obtained analogously to methods described in Examples 14 to 19
above) was dissolved in a mixture of 22.5 mL of iso-propanol, 7.5
mL of purified water and 37.1 mg of hydrochloric acid (32%) at
70.degree. C. The solution was agitated for 3 h at 70.degree. C.
and thereafter cooled to 55.degree. C. over 0.5 h, whereupon
crystallisation started without seeding. The suspension was then
cooled to 0.degree. C. over 5.5 h. The suspension was agitated for
740 min at the final temperature. The crystals were filtered off
and washed with 7.5 mL of iso-propanol and thereafter dried at
40.degree. C. under reduced pressure.
[0137] The crystals were analysed by XRPD, DSC and TGA. The
analyses showed essentially the same XRPD pattern, DSC thermogram,
and decrease in mass, as those exhibited by the form obtained
according to Example 14 above.
EXAMPLE 25
[0138] 3.0 g of EtO.sub.2C--CH.sub.2--(R)Cgl--Aze--Pab--OH
(obtained analogously to methods described in Examples 14 to 19
above) was dissolved in a mixture of 22.5 mL iso-propanol and 7.5
mL purified water at 70.degree. C. The solution was agitated for 3
h at 70.degree. C. and thereafter cooled to 55.degree. C. over 0.5
h, whereupon crystallisation started without seeding. The
suspension was then cooled to 0.degree. C. over 5.5 h. The
suspension was agitated for 760 min at the final temperature. The
crystals were filtered off and washed with 7.5 mL of iso-propanol
and thereafter dried at 40.degree. C. under reduced pressure.
[0139] The crystals were analysed by XRPD, DSC and TGA. The
analyses showed essentially the same XRPD pattern, DSC thermogram,
and decrease in mass, as those exhibited by the form obtained
according to Example 14 above.
Abbreviations
[0140] vs=very strong
[0141] s=strong
[0142] m=medium
[0143] w=weak
[0144] vw=very weak
* * * * *