Note: Descriptions are shown in the official language in which they were submitted.
21(38~86
The invention relates to a crystalline form of the
(R)-(-)-2-cycloheptyl-N-methylsulfonyl- [4-(2-quinol inyl -
methoxy)-phenyl]-acetamide, a process for its preparation
and its use in medicaments.
(R)-(-)-2-Cycloheptyl-N-methylsulfo n y 1 - t 4-(2-qui no 1 i ny 1 -
methoxy)-phenyl]-acetamide of the formula (I),
~ N ~
o,~o
CO-NH-SO2-CH3
which is an inhibitor of leukotriene synthesis, its
preparation and its use in medicaments, is already
described in EP 344 519.
According to the preparation process described therein,
the compound of the formula (I) is obtained in the form
of a non-crystalline powder. A solvate-free, crystalline
modification is hitherto unknown.
However, it has become evident that the non-crystalline
form of the compound (I) has crucial disadvantages, in
particular in the preparation of solid medicaments. Thus,
medicaments which contain the compound of the formula (I)
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in the dmorphous form exhibit very unsatisfactory storage
stability for example Thi s phy5 i cal instability
which preferentially arises when the preparations are
stored over a relatively long period of time at tempera-
tures above 30C, impairs the absorption efficacy and, inparticular, the safety of these preparations. It is
therefore of qreat importance to make available a stable
form of the compound of the formula (I), which does not
possess the abovementioned disadvantages, for preparing
medicaments.
A novel crystalline form of the compound (R)-(-)-2-cyclo-
heptyl-N-methylsulfonyl- [4-(2-quinolinylmethoxy)-
phenyl]-acetamide has now been found which is distin-
guished, in comparison with the known non-crystalline
form, by increased physical stability and reduced sensi-
tivity to pressure, and is therefore considerably more
suitable for the preparation of various medicament forms
than is the non-crystalline form.
The preparation of the novel crystalline form of the
compound of the formula (I) according to the invention is
effected, e.g., by the compound of the formula (I) in
non-crystalline form being suspended in inert organic
solvents, optionally in the presence of water, and being
treated at elevated temperatures until it is quantita-
tively converted into the crystalline modification, andthe resulting crystals of the crystalline modification
then being separated off by customary methods and, to
remove any solvent residues which may be present, dried
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to constant weight at temperatures of +20C to +70C.
The duration of the conversion depends on the nature of
the solvent and the temperature selected. As a rule, it
amounts to several days to weeks.
Lower alcohols having 1 to 6 carbon atoms are preferably
employed as solvents; ethanol or isopropanol is pre-
ferably used. In this context, mixtures of the alcohols
with water in the ratio of one part of alcohol to 20
parts of water, preferably of one part of alcohol to 10
parts of water, are very particularly preferred. The use
of ethanol or isopropanolJwater mixtures in the ratio 1:8
is very particularly preferred.
The conversion of the non-crystalline form into the
crystalline form of the compound of the formula (I) is
usually effected by stirring or shaking the suspension at
elevated temperatures.
The separation of the crystals from the water/solvent
mixture takes place according to customary methods, such
as, for example, by filtration, decanting off, centri-
fugation or the like. Subsequently, the crystals aredried to constant mass at an elevated temperature, for
example at +50C or in vacuo.
The complete conversion of the non-crystalline form into
the crystalline modification is determined by DSC (dif-
ferential scanning calorimetry), spectroscopic or
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crystallographic methods.
A more rapid process, which is particularly suitable for
preparing relatively large quantities of crystalline
active compound, is achieved with the aid of seed crys-
tals, by, for example, the non-crystalline active com-
pound being suspended in a mixture of water and ethanol
in the ratio 8:1, the suspension being heated to +70C,
some seeds of the crystalline active compound being
added, and the mixture being stirred for about 4 h until
the non-crystalline active compound has been quantita
tively converted into the crystalline active compound.
However~ if the time of stirring is extended, the com-
plete conversion can also be effected at an elevated
temperature below +70C, for example in a temperature
range of ~40~ to +60C, or in other solvent mixtures,
such as, for example, water and isopropanol, or in
solvent mixtures with other mixture ratios, such as, for
example, in mixtures of water and alcohol in the ratio of
15:1 to 25:1.
The crystalline modification of the (R)-(-)-2-cyclo-
heptyl-N-methylsulfony1- [4-(2-quinolinylmethoxy)-
phenyl]-acetamide according to the invention possesses a
characteristic IR spectrum.
The thermogram of the crystalline modification according
to the invention, recorded by means of DSC (differential
scanning calorLmetry) under atmospheric pressure, shows
an endothermic melting peak at 124-127C and thus differs
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unan~iguously from the thermograms of other forms of the
active compound.
soth the X-ray diffractograms and the 13C solid NMR
spectra are characteristic of the crystalline modifica-
tion according to the invention. The density of the
crystalline (R)-(~)-2-cycloheptyl-N-methylsulfonyl- t4-
(2-quino 1 inyl methoxy)-phenyl]-acetamide is 1.30 g/cm3.
The present invention also includes pharmaceutical
preparations which, besides inert non-toxic pharmaceuti-
cally suitable auxiliaries and vehicles, contain thecrystalline form of the compound of the formula (I)
according to the invention, or which comprise the crys-
talline modification of the compound of the formula (I),
as well as processes for producing these preparations. In
this context, solid drug forms and suspensions are to be
mentioned as being preferred. The crystalline active
compound is particularly suitable for preparing solid
medicament~, e.g. in the form of tablets, pill8, coated
tablets or capsules.
In these preparations, the novel crystalline modification
of the compound of the formula (I) should be present in
a concentration of 0.1 to 99.5~ by weight, preferably of
0.5 to 95~ by weight, of the total mixture.
As well as the crystalline modification of the compound
of the formula (I), the pharmaceutical preparations may
also contain other pharmaceutical active compounds.
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The abovementioned pharmaceutical preparations can be
prepared in a customary manner by known methods, for
example with one or more auxiliaries or vehicles.
Preparation examples
Example 1
Preparation of seed crystals
1 g of non-crystalline active compound is suspended in a
water/isopropanol mixture (8 ml:1 ml), and stirred at
+50C for 14 days. The suspension is subsequently fil-
tered and dried in vacuo to constant mass.
Example 2
Crystallisation by seeding
1 g of non-crystalline active compound is suspended in a
water/ethanol mixture (8 ml:l ml), seeded with a few seed
crystals and stirred at +70C for 4 hours. The suspension
is subsequently filtered and dried to constant mass.
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