CRYSTAL FORM OF QUINOLINE COMPOUND AND PROCESS FOR ITS PRODUCTION

Abstract

A method for producing a drug substance of crystalline pitavastatin calcium excellent in stability, is presented. In the production of a compound (pitavastatin calcium) represented by the formula (1):

##STR00001##

The water content is adjusted to a level of from 5 to 15%, and the crystal form is controlled to be crystal form A, thereby to obtain a drug substance excellent in stability.

Claims

1. A method of storing a pitavastatin calcium salt, comprising: maintaining a water content of the pitavastatin calcium salt at greater than 4% (w/w); wherein: the pitavastatin calcium salt is a compound according to formula (1): ##STR00010## and an X-ray powder diffraction pattern of the pitavastatin calcium salt, as measured using CuKα radiation, exhibits peaks at diffraction angles (2θ) of 10.40°, 13.20°, and 30.16°.

2. The method according to claim 1, comprising maintaining the water content of the pitavastatin calcium salt at 5% (w/w) or greater.

3. The method according to claim 1, comprising maintaining the water content of the pitavastatin calcium salt at 5 to 15% (w/w).

4. The method according to claim 1, comprising maintaining the water content of the pitavastatin calcium salt at 7% (w/w) or greater.

5. The method according to claim 1, comprising maintaining the water content of the pitavastatin calcium salt at 7 to 13% (w/w).

6. The method according to claim 1, comprising maintaining the water content of the pitavastatin calcium salt at 7 to 15% (w/w).

7. The method according to claim 1, comprising maintaining the water content of the pitavastatin calcium salt at 9% (w/w) or greater.

8. The method according to claim 1, comprising maintaining the water content of the pitavastatin calcium salt at 9 to 13% (w/w).

9. The method according to claim 1, wherein the pitavastatin calcium salt is produced by: adding a calcium compound to a solution comprising a compound according to formula (2): ##STR00011## wherein M+ represents an alkali metal ion, dissolved in water or in a C.sub.1-4 alcohol comprising at least 60% of water; filtering precipitated crystals; and drying the crystals so that a water content of the crystals is greater than 4% (w/w).

10. The method according to claim 2, wherein the pitavastatin calcium salt is produced by: adding a calcium compound to a solution comprising a compound according to formula (2): ##STR00012## wherein M+ represents an alkali metal ion, dissolved in water or in a C.sub.1-4 alcohol comprising at least 60% of water; filtering precipitated crystals; and drying the crystals so that a water content of the crystals is 5% (w/w) or greater.

11. The method according to claim 3, wherein the pitavastatin calcium salt is produced by: adding a calcium compound to a solution comprising a compound according to formula (2): ##STR00013## wherein M+ represents an alkali metal ion, dissolved in water or in a C.sub.1-4 alcohol comprising at least 60% of water; filtering precipitated crystals; and drying the crystals so that a water content of the crystals is 5 to 15% (w/w).

12. The method according to claim 4, wherein the pitavastatin calcium salt is produced by: adding a calcium compound to a solution comprising a compound according to formula (2): ##STR00014## wherein M+ represents an alkali metal ion, dissolved in water or in a C.sub.1-4 alcohol comprising at least 60% of water; filtering precipitated crystals; and drying the crystals so that a water content of the crystals is 7% (w/w) or greater.

13. The method according to claim 5, wherein the pitavastatin calcium salt is produced by: adding a calcium compound to a solution comprising a compound according to formula (2): ##STR00015## wherein M+ represents an alkali metal ion, dissolved in water or in a C.sub.1-4 alcohol comprising at least 60% of water; filtering precipitated crystals; and drying the crystals so that a water content of the crystals is 7 to 13% (w/w).

14. The method according to claim 6, wherein the pitavastatin calcium salt is produced by: adding a calcium compound to a solution comprising a compound according to formula (2): ##STR00016## wherein M+ represents an alkali metal ion, dissolved in water or in a C.sub.1-4 alcohol comprising at least 60% of water; filtering precipitated crystals; and drying the crystals so that a water content of the crystals is 7 to 15% (w/w).

15. The method according to claim 7, wherein the pitavastatin calcium salt is produced by: adding a calcium compound to a solution comprising a compound according to formula (2): ##STR00017## wherein M+ represents an alkali metal ion, dissolved in water or in a C.sub.1-4 alcohol comprising at least 60% of water; filtering precipitated crystals; and drying the crystals so that a water content of the crystals is 9% (w/w) or greater.

16. The method according to claim 8, wherein the pitavastatin calcium salt is produced by: adding a calcium compound to a solution comprising a compound according to formula (2): ##STR00018## wherein M+ represents an alkali metal ion, dissolved in water or in a C.sub.1-4 alcohol comprising at least 60% of water; filtering precipitated crystals; and drying the crystals so that a water content of the crystals is 9 to 13% (w/w).

17. The method according to claim 9, wherein drying the crystals comprises drying under reduced pressure.

18. The method according claim 9, wherein drying the crystals comprises drying at a temperature of from 15 to 40° C.

19. The method according to claim 1, wherein maintaining the water content of the pitavastatin calcium salt comprises storing under air tight conditions.

20. The method according to claim 1, wherein the X-ray powder diffraction pattern of the pitavastatin calcium salt, as measured using CuKα radiation, exhibits peaks at diffraction angles (2θ) of 4.96°, 6.72°, 9.08°, 10.40°, 10.88°, 13.20°, 13.60°, 13.96°, 18.32°, 20.68°, 21.52°, 23.64°, 24.12°, 27.00°, and 30.16°.

21. A pharmaceutical or veterinary medicine composition, comprising a pitavastatin calcium salt stored by the method according to claim 1.

22. A method of storing a pitavastatin calcium salt, comprising: maintaining a water content of the pitavastatin calcium salt at greater than 4% (w/w) and at most 15% (w/w); wherein: the pitavastatin calcium salt is a compound according to formula (1): ##STR00019## an X-ray powder diffraction pattern of the pitavastatin calcium salt, as measured using CuKα radiation, exhibits peaks at diffraction angles (2θ) of 4.96°, 6.72°, 9.08°, 10.40°, 10.88°, 13.20°, 13.60°, 13.96°, 18.32°, 20.68°, 21.52°, 23.64°, 24.12°, 27.00°, and 30.16°; and a water content of the pitavastatin calcium salt at an initial stage is from 7% (w/w) to 13% (w/w).

23. The method according to claim 22, comprising maintaining the water content of the pitavastatin calcium salt at 5 to 15% (w/w).

24. The method according to claim 22, comprising maintaining the water content of the pitavastatin calcium salt at 7 to 15% (w/w).

25. The method according to claim 22, comprising maintaining the water content of the pitavastatin calcium salt at 9 to 15% (w/w).

26. The method according to claim 22, wherein maintaining the water content of the pitavastatin calcium salt comprises storing under air tight conditions.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0031] A more complete appreciation of the invention and many of the attendant advantages thereof will be readily obtained as the same becomes better understood by reference to the following detailed description when considered in connection with the accompanying drawings, wherein:

[0032] FIG. 1 is a powder X-ray diffraction pattern of crystal form A wherein the water content is 8.78%.

[0033] FIG. 2 is a powder X-ray diffraction pattern, when the crystals used in FIG. 1 are dried to bring the water content to be 3.76%.

DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS

[0034] Now, the present invention will be described in detail.

[0035] Pitavastatin calcium having crystal form A is characterized by its powder X-ray diffraction pattern.

TABLE-US-00002 Diffraction angle Relative intensity (2θ) (°) d-lattice spacing (>25%) 4.96 17.7999 35.9 6.72 13.1423 55.1 9.08 9.7314 33.3 10.40 8.4991 34.8 10.88 8.1248 27.3 13.20 6.7020 27.8 13.60 6.5053 48.8 13.96 6.3387 60.0 18.32 4.8386 56.7 20.68 4.2915 100.0 21.52 4.1259 57.4 23.64 3.7604 41.3 24.12 3.6866 45.0 27.00 3.2996 28.5 30.16 2.9607 30.6

[0036] Apparatus:

[0037] Powder X-ray diffraction measuring apparatus: MXLabo (manufactured by MacScience)

[0038] Ray source: Cu, wavelength: 1.54056 A, Goniometer: Vertical Goniometer

[0039] Monochrometer: Used, Auxiliary means: Nil, X-ray tube voltage: 50.0 Kv, Tube current: 30.0 mA

[0040] Measuring Method:

[0041] Prior to the measurement, X-ray tube alignment is tested by using silicon (standard substance).

[0042] About 100 mg of a sample is put on a glass plate for the sample and flattened, followed by measurement under the following conditions.

[0043] Range of data: from 3.0400 to 40.0000 deg,

[0044] Number of data points: 925

[0045] Scanning axis: 2θ/θ, θ axis angle: No setting

[0046] Sampling interval: 0.0400 deg,

[0047] Scanning speed: 4.800 deg/min

[0048] The present invention also provides a production process to control pitavastatin calcium to have crystal form A.

##STR00007##

[0049] The starting material is an alkali metal salt of pitavastatin shown by the formula (2), and the alkali metal may, for example, be lithium, sodium or potassium, preferably sodium.

[0050] As the calcium compound, calcium chloride or calcium acetate may, for example, be preferred, and its amount is within a range of from 0.3 to 3 mols, preferably from 0.5 to 2 mols, per mol of the compound of the formula (2).

[0051] The alkali metal salt of pitavastatin of the formula (2) may not necessarily be isolated. For example, the Ca salt may be produced as continued from the reaction of hydrolyzing e.g. a compound of the formula (3).

##STR00008##

[0052] As a solvent to be used, water or a C.sub.1-4 alcohol containing at least 60% of water, is preferred. The C.sub.1-4 alcohol may, for example, be methyl alcohol, ethyl alcohol, n-propyl alcohol, isopropyl alcohol, n-butyl alcohol, isobutyl alcohol, sec-butyl alcohol or tert-butyl alcohol.

[0053] The amount of the solvent to be used, is usually within a range of from 3 to 100 times by mass, preferably within a range of from 5 to 30 times by mass, to the amount of the compound of the formula (2).

[0054] The crystallization temperature is not particularly limited, but it is usually within a range of from −10 to 70° C., preferably within a range of from −5 to 40° C., more preferably within a range of from 0 to 20° C. The crystallization time is not particularly limited, but a crystallization time of from about 30 minutes to 15 hours, is usually sufficient.

[0055] As a method for crystallization, a method of carrying out the crystallization in a standing still state, or a method of carrying out the crystallization with stirring, may, for example, be mentioned. However, it is preferred to carry out the crystallization with stirring.

[0056] Further, seed crystals of crystal form A may be used as the case requires.

[0057] Precipitated crystals will then be filtered and dried. In the present invention, it is very important to adjust the water content. The drying temperature is not particularly limited, but is preferably within a range of from 15 to 40° C.

[0058] The water content is adjusted so that it will finally be within a range of from 5 to 15% (W/W), preferably within a range of from 7 to 15% (W/W), more preferably within a range of from 7 to 13% (W/W), most preferably within a range of from 9 to 13% (W/W).

[0059] The obtained pitavastatin calcium will be pulverized and then used as a drug substance for pharmaceuticals.

[0060] Administration of the compound of the present invention may, for example, be parenteral administration in the form of an injection drug (subcutaneous, intravenous, intramuscular or intraperitoneal injection), an ointment, a suppository, an aerosol or the like, or oral administration in the form of tablets, capsules, granules, pills, a syrup drug, a liquid drug, an emulsion drug or a suspension drug.

[0061] A pharmaceutical or veterinary medicine composition containing the compound of the present invention, contains from about 0.001 to 30%, preferably from about 0.01 to 10% of the compound of the present invention, based on the weight of the total composition.

[0062] In addition to the compound of the present invention or the composition containing such a compound, other pharmaceutically or veterinary medicinary active compound may be incorporated.

[0063] The clinical dosage of the compound of the present invention may vary depending upon e.g. the age, the body weight, the sensitivity of the patient or the degree of symptom. However, the effective dosage is usually at a level of from 0.003 to 100 mg, preferably from 0.01 to 10 mg, per day for an adult. However, if necessary, a dosage outside this range may be employed.

[0064] The compound of the present invention may be formulated for administration in accordance with a common method for preparation of medicines. Namely, tablets, capsules, granules or pills for oral administration may be formulated by using, for example, an excipient, such as sucrose, lactose, glucose, starch or mannitol; a binder, such as hydroxypropyl cellulose, syrup, gum arabic, gelatin, sorbitol, tragacanth, methyl cellulose or polyvinylpyrrolidone; a disintegrant, such as starch, carboxymethyl cellulose or its calcium salt, fine crystal cellulose, or polyethylene glycol; a lubricant, such as talc, magnesium or calcium stearate, or silica; a lubricating agent, such as sodium laurate or glycerol.

[0065] An injection drug, a liquid drug, an emulsion drug, a suspension drug, a syrup drug and an aerosol drug may be prepared by using, for example, a solvent for the active ingredient, such as water, ethyl alcohol, isopropyl alcohol, propylene glycol, 1,3-butylene glycol or polyethylene glycol; a surfactant, such as sorbitan fatty acid ester, polyoxyethylene sorbitan fatty acid ester, polyoxyethylene fatty acid ester, polyoxyethylene ether of hydrogenated castor oil, or lecithin; a suspending agent, such as carboxymethyl sodium salt, or a cellulose derivative such as methyl cellulose, tragacanth, a natural rubber such as gum arabic; a preservative, such as a p-hydroxybenzoate, benzalkonium chloride or a sorbic acid salt.

[0066] For an ointment which is a percutaneous absorption type formulation, white petrolatum, liquid paraffin, a higher alcohol, macrogol ointment, hydrophilic ointment or an aqueous gel base material may, for example, be used.

[0067] A suppository may be prepared by using e.g. cacao butter, polyethylene glycol, lanolin, fatty acid triglyceride, coconut oil or polysorbate.

[0068] Now, the present invention will be described in further detail with reference to Example. However, it should be understood that the present invention is by no means restricted to such a specific Example.

[0069] The compound (5) used in the Example was prepared in accordance with the method disclosed in WO95/23125.

Example 1

[0070] ##STR00009##

[0071] 2.71 kg (6.03 mol) of the compound (5) was dissolved in 50 kg of ethanol with stirring, and after confirming the solution to be a uniform solution, 58.5 kg of water was added. After cooling it to from −3 to 3° C., 3.37 liters of a 2 mol/liter sodium hydroxide aqueous solution was dropwise added thereto, followed by stirring at the same temperature for 3 hours to complete the hydrolytic reaction. In order to introduce the entire amount of the sodium hydroxide aqueous solution to the reaction system, 4.70 kg of water was used.

[0072] The reaction mixture was distilled under reduced pressure to remove the solvent, and after removing 52.2 kg of ethanol/water, the internal temperature was adjusted to from 10 to 20° C. Into the obtained concentrated solution, a separately prepared calcium chloride aqueous solution (95% CaCl.sub.2 775 g/water 39.3 kg, 6.63 mol) was dropwise added over a period of 2 hours. In order to introduce the entire amount of the calcium chloride aqueous solution into the reaction system, 4.70 kg of water was used. After completion of the dropwise addition, stirring at the same temperature was continued for 12 hours, whereupon precipitated crystals were collected by filtration. The crystals were washed with 72.3 kg of water and then dried under reduced pressure in a drier at 40° C. while paying an attention to the product temperature until the water content became 10%, to obtain 2.80 kg (yield: 95%) of pitavastatin calcium as white crystals.

[0073] The powder X-ray diffraction was measured to confirm the crystals to be crystal form A.

[0074] According to the present invention, an industrial method for producing a crystalline drug substance of pitavastatin calcium excellent in stability, has been established.

[0075] In the above detailed description, reference was made by way of non-limiting example to preferred embodiments of the invention. Obviously, numerous modifications and variations of the present invention are possible in light of the above teachings. It is therefore to be understood that within the scope of the appended claims, the invention may be practiced otherwise than as specifically described herein.