Classifications

• • C—CHEMISTRY; METALLURGY
  • C07—ORGANIC CHEMISTRY
  • C07D—HETEROCYCLIC COMPOUNDS
  • C07D333/00—Heterocyclic compounds containing five-membered rings having one sulfur atom as the only ring hetero atom
  • C07D333/02—Heterocyclic compounds containing five-membered rings having one sulfur atom as the only ring hetero atom not condensed with other rings
  • C07D333/04—Heterocyclic compounds containing five-membered rings having one sulfur atom as the only ring hetero atom not condensed with other rings not substituted on the ring sulphur atom
  • C07D333/06—Heterocyclic compounds containing five-membered rings having one sulfur atom as the only ring hetero atom not condensed with other rings not substituted on the ring sulphur atom with only hydrogen atoms, hydrocarbon or substituted hydrocarbon radicals, directly attached to the ring carbon atoms
  • C07D333/14—Radicals substituted by singly bound hetero atoms other than halogen
  • C07D333/16—Radicals substituted by singly bound hetero atoms other than halogen by oxygen atoms
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61K—PREPARATIONS FOR MEDICAL, DENTAL OR TOILETRY PURPOSES
  • A61K31/00—Medicinal preparations containing organic active ingredients
  • A61K31/33—Heterocyclic compounds
  • A61K31/38—Heterocyclic compounds having sulfur as a ring hetero atom
  • A61K31/381—Heterocyclic compounds having sulfur as a ring hetero atom having five-membered rings
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61P—SPECIFIC THERAPEUTIC ACTIVITY OF CHEMICAL COMPOUNDS OR MEDICINAL PREPARATIONS
  • A61P13/00—Drugs for disorders of the urinary system
  • A61P13/10—Drugs for disorders of the urinary system of the bladder
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61P—SPECIFIC THERAPEUTIC ACTIVITY OF CHEMICAL COMPOUNDS OR MEDICINAL PREPARATIONS
  • A61P25/00—Drugs for disorders of the nervous system
  • A61P25/24—Antidepressants
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61P—SPECIFIC THERAPEUTIC ACTIVITY OF CHEMICAL COMPOUNDS OR MEDICINAL PREPARATIONS
  • A61P43/00—Drugs for specific purposes, not provided for in groups A61P1/00-A61P41/00
• • C—CHEMISTRY; METALLURGY
  • C07—ORGANIC CHEMISTRY
  • C07D—HETEROCYCLIC COMPOUNDS
  • C07D333/00—Heterocyclic compounds containing five-membered rings having one sulfur atom as the only ring hetero atom
  • C07D333/02—Heterocyclic compounds containing five-membered rings having one sulfur atom as the only ring hetero atom not condensed with other rings
  • C07D333/04—Heterocyclic compounds containing five-membered rings having one sulfur atom as the only ring hetero atom not condensed with other rings not substituted on the ring sulphur atom
  • C07D333/06—Heterocyclic compounds containing five-membered rings having one sulfur atom as the only ring hetero atom not condensed with other rings not substituted on the ring sulphur atom with only hydrogen atoms, hydrocarbon or substituted hydrocarbon radicals, directly attached to the ring carbon atoms
  • C07D333/14—Radicals substituted by singly bound hetero atoms other than halogen
  • C07D333/20—Radicals substituted by singly bound hetero atoms other than halogen by nitrogen atoms

Definitions

• the invention deals with a new method of preparation of a crystalline form with defined physical parameters of (5)-N-methyl-3-(l-naphthyloxy)-3-(2-thienyl)propylamine
• hydrochloride known under the generic name duloxetine, of formula I.
• Duloxetine is an inhibitor of serotonin and noradrenaline reuptake and is therapeutically used in the sphere of depression and urinary incontinence.
• hydrochloride i.e. substance I
• duloxetine contains impurities, especially the 3 -isomer of formula II
• Duloxetine usually crystallizes in the form of small needles, which causes trouble during stirring of the crystallization mixture and subsequent filtration. During the final treatment, i.e. e.g. sieving, very airy material is produced that is very difficult to handle.
• Apparent density is, similarly to liquids, defined as the weight of material occupying a certain volume (g/cm 3 ). Apparent density is commonly measured in such a way that the material is poured into a cylinder with a defined volume and apparent density is determined using the following formula:
• Another parameter is the particle size distribution, which defines the relative quantity of particles present in a sample depending on their size. Particle size distribution can e.g. be determined with laser diffraction using commercially available devices (e.g. Malvern Master seizer 2000). In this case the particle size is expressed by means of the diameter of the equivalent sphere, which is a theoretical sphere of the same volume as the analyzed particle. In the comparison of the particle size distributions of various samples it is convenient to monitor the values of the percentiles d(0.1), d(0.5) and d(0.9). These percentiles express that 10, 50 and 90 % of particles are smaller than the value of the percentile.
• the shape of crystals is closely related to apparent density and particle size distribution.
• the material consisting of tiny needles or sticks, which are often united in bundles, exhibits inconvenient characteristics as low apparent density and difficult pouring properties.
• the appearance of crystals can be observed with a common optical microscope and their shape and size can be described with morphological parameters of pattern analysis.
• the crystal area is a parameter related both to the shape and the size of the particle. This parameter expresses the actual area of the particle projection in a calibrated image.
• the shape of the crystal well characterizes the morpho logical parameters of elongation, which is defined as a ratio of the maximum and minimum Feret's diameters.
• the maximum and minimum Feret's diameters are the maximum and minimum distances, resp., between two parallels applied to the measured particle.
• the value of the elongation parameter approximates 1. In the case of needle-like particles the value of the elongation parameter is relatively high.
• This invention describes a method of preparation of duloxetine with a minimum content of impurities in a high yield and at the same time with physical characteristics, such as apparent weight, and size and shape of crystals, advantageous for use in pharmaceutical production.
• the essence of the invention comprises a method for the preparation of a crystalline form of (5)-N-methyl-3-(l-naphthyloxy)-3-(2-thienyl)propylamine hydrochloride, known under the generic name duloxetine, of formula I,
• EP patent 1 758 879 patent describes, in Example 7, crystallization of duloxetine from ethyl methyl ketone without mentioning any details.
• WO 2006/099468 describes crystallization of duloxetine by dissolution thereof under boiling and subsequent cooling in a mixture of an organic solvent and water where the content of water is at least 1.75%.
• a preferred solvent is acetone and water or 2-propanol.
• duloxetine precipitates in the form of long fibres or needles, so that the crystallization mixture is very difficult to stir and the time of filtration and washing of the filter cake get consequently longer. After drying, sieving of the obtained material is difficult and the final product is very fine with a low apparent density (typically about 0.2 g/cm 3 ).
• a low apparent density typically about 0.2 g/cm 3 .
• duloxetine prepared by known methods typically varies in the range of 0.18 to 0.25 g/cm 3 .
• Duloxetine prepared in accordance with the crystallization procedure described herein typically achieves values of 0.30 to 0.40 g/cm 3 .
• Apparent density of the material is related to the size and shape of particles of the particular material.
• FIG. 1 An example of particle size distribution (measured in the Malvern Mastersizer 2000 device) of duloxetine prepared in accordance with known methods is shown in Fig. 1.
• Examples of particle size distribution of recrystallized duloxetine are shown in Figs. 2 and 3. These figures illustrate that with the use of the duloxetine recrystallization method described herein the values of percentiles d(0.5) and d(0.9) of particle size distribution considerably change.
• duloxetine prepared in accordance with the formerly described procedures achieves the values of up to about 90 ⁇
• duloxetine prepared in accordance with the new procedure achieves a value that is more than twice as high (see Fig. 4 as compared to Figs. 5 and 6).
• suitably performed recrystallization also influences their shape, which is documented by photographs (Figs. 4, 5 and 6) as well as the morphological parameters of elongation (see Figs.
• Duloxetine prepared in accordance with known procedures contains a relatively high proportion of stick-shaped particles. In such material (Fig. 7) 33% of particles only have the elongation parameter within the interval of 1 to 2.
• particles of recrystallized duloxetine are smooth and transparent, of a lamellar shape (Figs. 5 and 6). Their elongation parameter (Figs. 8 and 9) is within the interval of 1-2 for 74% of particles. Accordingly, the particles of recrystallized duloxetine exhibit considerably smaller elongation than duloxetine particles obtained by prior art methods.
• the solvents used for crystallization can be generally divided into protic solvents, which contain the OH group in their chemical structure, and aprotic solvents.
• duloxetine dissolves very well in protic solvents and their mixtures.
• duloxetine is poorly soluble in aprotic solvents such as ketones (e.g. acetone, ethyl methyl ketone), or esters (e.g. ethyl acetate) and duloxetine is virtually insoluble in hydrocarbons (e.g. heptane), or ethers (e.g. diethyl ether, tert-butyl methyl ether).
• Suitable solvents for recrystallization of duloxetine include, above all, relatively less polar C3- 6 ketones or C3-6 esters, such as acetone, ethyl methyl ketone, ethyl acetate, in mixtures with protic solvents, such as water, methanol, ethanol or 2-propanol.
• a suitable content of the more polar solvent in the mixture of solvents is roughly from 50% by vol. to 0% by vol. and may conveniently decrease during the crystallization from higher values to zero. In the course of the crystallization the water content varies in the range from 1.70% by vol. to 0% by vol. Reduction of the content of the protic solvent in the mixture can be achieved in the following ways:
• the crystallization can be carried out either by heating a suspension of duloxetine in a mixture of solvents, adjusting their proportions and subsequent cooling, or by preparing a duloxetine solution in a hot mixture of solvents, adjusting their proportions and subsequent cooling.
• the size and shape of duloxetine crystals depends on the stirring time as well as on the
• a suitable stirring time of the suspension is in the range of from about 0.5 hour to 24 hours, most preferably from 1 hour to 6 hours.
• a suitable temperature for crystallization is in the range of about 30 °C to 120 °C, most preferably from 40 °C to the boiling point of the solvent or mixture of solvents.
• a preferable embodiment of recrystallization of duloxetine suspension consists in stirring of the mixture at the boiling temperature of the solvent or the boiling temperature of the mixture of solvents for 0.5 to 1 hour, followed by cooling to 30 to 40 °C and stirring of the mixture.
• duloxetine crystals by means of suitably performed crystallization, which results in a change of physical properties of the obtained material.
• These physical properties can be characterized by various methods, e.g. by determining the apparent density, distribution of particles, the elongation parameter, etc. Physical properties have a principal influence both on processes used within the preparation of duloxetine (e.g. filtration or drying speeds) and on processes used in the preparation of the dosage form (e.g. pouring of the material, granulation, direct compression, homogenization, or mixing with auxiliary substances).
• Fig. 1 Particle size distribution of crystalline duloxetine prepared according to Example 2 (prior method)
• Fig. 2 Particle size distribution of crystalline duloxetine prepared according to Example 3
• Fig. 3 Particle size distribution of crystalline duloxetine prepared according to Example 6
• Fig. 4 Crystalline duloxetine prepared according to Example 2 (prior method)
• Fig. 5 Crystalline duloxetine prepared according to Example 3.
• Fig. 7 Elongation of particles of crystalline duloxetine prepared according to Example 2 (prior method)
• Fig. 8 Elongation of particles of crystalline duloxetine prepared according to Example 3
• Fig. 9 Elongation of particles of crystalline duloxetine prepared according to Example 6 Examples
• the evaporation residue is dissolved in dimethyl sulfoxide (300 ml) and a 5M solution of potassium hydroxide (400 ml) is added dropwise under reflux. After two hours at 60°C the mixture is diluted with water (1000 ml) and duloxetine base is extracted with tert-butyl methyl ether (300 ml). The solution is diluted with ethyl methyl ketone (butanone) and cooled to 0 °C. Then, pH is adjusted to the value of about 5 by dropwise addition of concentrated hydrochloric acid. Then the precipitated lightly brownish crystals are aspirated. The yield of crude duloxetine is 183 g (55%), m.p. 167-169 °C.
• a suspension of duloxetine (183 g) in ethyl methyl ketone (1 100 ml) is refluxed for 1 hour.
• Duloxetine (160 g) is stirred up in 500 ml of ethyl methyl ketone and 8.5 ml of water are added. The mixture is heated to boil and the suspension is refluxed for 30 minutes. Then, 300 ml of MEK (butanone) are added dropwise under reflux during 30 minutes. After the addition the suspension is cooled to 35 °C during 1 hour and stirred for 1 hour. The crystals are aspirated, washed with ethyl methyl ketone and tert-butyl methyl ether. Yield: 144 g (90%), m.p. 170.5-171.5 °C.
• Duloxetine 160 g is stirred up in 750 ml of ethyl methyl ketone and 75 ml of methanol and the mixture is heated to boil. Then, 150 ml (azeotropic mixture of methanol / ethyl methyl ketone) are removed by distillation during 30 minutes and subsequently 150 ml of ethyl methyl ketone are added dropwise. The suspension is cooled to 30 °C during 1 hour and stirred at this temperature for 1 hour. The crystals are aspirated, washed with ethyl methyl ketone and tert-butyl methyl ether. Yield: 146 g (90%), m.p. 170.5-171.5 "C.
• Duloxetine 160 g is stirred up in 1200 ml of ethyl methyl ketone and 19 ml of water are added. Then, 300 ml (azeotropic mixture of water / ethyl methyl ketone) are removed by distillation during one hour. The suspension is cooled to 30 °C during one hour and stirred for 1 hour. The crystals are aspirated, washed with ethyl methyl ketone and tert-butyl methyl ether. Yield: 144 g (90%), m.p. 170.5-171.5 °C.
• Duloxetine 160 g is stirred up in 750 ml of ethyl methyl ketone and 75 ml of ethanol and the mixture is heated to boil. Then, 150 ml (azeotropic mixture of methanol / ethyl methyl ketone) are removed by distillation during 60 minutes and at the same time 150 ml of ethyl methyl ketone are added dropwise. The suspension is cooled to 30 °C during 1 hour and stirred at this temperature for 1 hour. The crystals are aspirated, washed with ethyl methyl ketone and tert- butyl methyl ether. Yield: 146 g (90%), m.p.: 170.5-171.5 °C.
• the apparent density was determined in such a way that the substance was freely poured (without shaking) into a graduated cylinder with the volume of 100 cm 3 and its weight was determined.
• Particle size distribution was determined by wet laser diffraction under the following conditions:
• the average of 20 measurements is considered as the result of the analysis.
• the parameters of area and elongation of crystals were obtained from photomicrographs of the samples by means of the NIS - Elements pattern analysis software.

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• 2009
  • 2009-09-02 CZ CZ2009-584A patent/CZ304602B6/cs not_active IP Right Cessation
• 2010
  • 2010-09-02 JP JP2012527196A patent/JP2013503823A/ja active Pending
  • 2010-09-02 CN CN2010800392370A patent/CN102482254A/zh active Pending
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  • 2010-09-02 MX MX2012002621A patent/MX2012002621A/es not_active Application Discontinuation
  • 2010-09-02 KR KR1020127004225A patent/KR20120047262A/ko not_active Withdrawn
  • 2010-09-02 EP EP10771629A patent/EP2473497A1/en not_active Withdrawn
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• 2012
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