# Patent

## Title
Crystalline forms of temozolomide and the method for preparing same

## Abstract

Provided in the present invention are a new method for preparing the crystalline forms of Temozolomide and three types of crystalline form of Temozolomide by the method. Said method comprises the following steps: a Temozolomide is dissolved into dimethyl sulphoxide, a second organic solvent is added for recrystallization to prepare the crystalline forms of Temozolomide, wherein the second organic solvent is an alcohol, a ketone, a halohydrocarbon or an ester.

## Background
CROSS-REFERENCE TO RELATED APPLICATION
This application is a national phase entry of International Application No. PCT/CN2014/089713, filed Oct. 28, 2014 and titled “The Crystalline Forms of Temozolomide and the Method for Preparing Same,” which claims priority to and the benefit of Chinese Patent Application No.: 201310521569.8, filed Oct. 29, 2013 and titled “The Crystalline Forms of Temozolomide and the Method for Preparing Same.” The contents of the above-identified Applications are relied upon and incorporated herein by reference in their entirety.
FIELD OF THE INVENTION
The present invention belongs to the pharmaceutical field and relates to crystalline forms of pharmaceutical compound. More specifically, the present invention relates to crystalline forms of an anti-tumor drug Temozolomide and the method for preparing thereof.
BACKGROUND OF THE INVENTION
Temozolomide (TMZ) is an alkylating anti-tumor drug containing an imidazotetrazine ring with an anti-tumor activity. Its chemical structure is presented as follows:




Temozolomide belongs to a pro-drug with no activity. It is usually converted to the active compound MITC (5-(3-methyltriazen-1-yl)-imidazole-4-carboxamide) under a physiological pH level via a non-enzymatic pathway, and MITC is further hydrolyzed to an active metabolite, showing its anti-tumor activity. In theory, the anti-tumor activity of MTIC is mainly produced by major DNA alkylation (methylation) with the 6th oxygen atom of guanine. Also, it can have secondary additional alkylation with the 7th nitrogen atom of guanine. Therefore, the subsequent cytotoxicity is considered to have the relationship with these abnormally-repaired methyl compounds.
Temozolomide compounds have been already synthesized. In recent years, however, it is continuously found that its new crystalline forms have excellent medicinal value. For example, U.S. Pat. No. 5,260,291 disclosed Temozolomide polymorphs prepared by using the following three different solvent systems: acetone and water (3:1), acetone and water (1:3), and water. Chinese Journal of Pharmaceuticals reproduced the method of U.S. Pat. No. 5,260,291, and reported the relevant data; US 20050187206 disclosed the methods for preparing various crystalline forms of Temozolomide by using a variety of solvents, such as pyridine, ethanol, acetone etc.; WO2008111092 disclosed Temozolomide monohydrate, prepared by the solvent of acetone and water (3:1); Chinese patent CN201110201186.3 disclosed a type of crystalline form of Temozolomide prepared by using a mixed solvent of acetone, acetonitrile and water.
The afore-mentioned methods have a problem caused by the solubility of TMZ, i.e. a large amount of solvent, which is up to a few times or even hundreds of times of Temozolomide, are required for dissolution, for example, in US20050187206, the amount of ethanol reached 270 times the amount of Temozolomide (v/w), and the amount of acetone used even reached more than 300 times the amount of Temozolomide (v/w). Alternatively, although the volume of the solvent is more than 10 times the amount of Temozolomide, the yield is low, thus it is unsuitable for industrial production. In addition, the crystalline forms prepared by the above-mentioned methods are unstable, e.g. in US20050187206, crystalline Form I of Temozolomide was transformed into crystalline Form II under a condition of being heated to approximately 30° C.
Therefore, it is necessary to find a stable crystalline form of Temozolomide for medicine application, specifically as an active pharmaceutical ingredient (API) in a solid pharmaceutical. In addition, the solvents used in the recrystallization methods of Temozolomide in the prior art were short of specificity, so that a small amount of impurities was contained in the obtained crystalline forms of Temozolomide. As a result, the application was affected.
CONTENT OF THE INVENTION
In order to solve the above problems, the present invention provides a novel method for preparing crystalline forms of Temozolomide and the crystalline forms prepared by the method.
According to the first aspect, the present invention provides a novel method for preparing crystalline forms of Temozolomide, characterized in that, the method comprises the following steps: dissolving Temozolomide in dimethylsulfoxide (DMSO), into which a second organic solvent is added for recrystallization, whereby the crystalline forms of Temozolomide are prepared. Wherein, the second organic solvent is an alcohol, a ketone, a halohydrocarbon or an ester. Preferably, the second organic solvent is ethanol, methanol, isopropanol, acetone, dichloromethane, ethyl acetate or glycol.
The method of the present invention for preparing crystalline forms of Temozolomide comprises the following steps: Temozolomide is prepared, into which DMSO with 7-20 times the amount of the Temozolomide (v/w) is added, the mixture of Temozolomide and DMSO is stirred and heated to make the Temozolomide dissolved, then a second organic solvent with 5-30 times the amount of the Temozolomide (v/w) is added, stirred, cooled down, crystallized by stirring, filtered to give the crystalline forms, and the resultant crystalline forms are washed by using the second organic solvent with 2-10 times the amount of the Temozolomide (v/w), and dried in vacuum to give the crystalline forms of Temozolomide.
More specifically, the method of the present invention for preparing crystalline forms of Temozolomide comprises the following steps: Temozolomide is prepared, into which DMSO with 7-15 times the amount of the Temozolomide (v/w) is added, the mixture of Temozolomide and DMSO is stirred and heated to 60-140° C. to make the Temozolomide dissolved, then a second organic solvent with 7-20 times the amount of the Temozolomide (v/w) is added, stirred for 5-15min, cooled down to 10-15° C., crystallized for 4 hours by stirring, filtered to give the crystalline forms, and the resultant crystalline forms are washed by using the second organic solvent with 2-5 times the amount of the Temozolomide (v/w), and dried in vacuum to give the crystalline forms of Temozolomide.
It should be noted that, in the method of the present invention for preparing crystalline forms of Temozolomide, no special requirements are needed on the stirring equipment and stirring speed during the formation of the three crystalline forms. Conventional stirring equipment and stirring speed can be used for preparing the crystalline forms.
The crystalline forms prepared by the method of the present invention are identified and confirmed to be three crystalline forms: Form A, Form B and Form C.
Wherein, when the second organic solvent is selected from ethanol or methanol, the crystalline forms are identified to be the same form and designated as Form A; when the second organic solvent is selected from isopropanol, acetone, dichloromethane or ethyl acetate, the crystalline forms are identified to be the same form and designated as Form B; when the second organic solvent is glycol, the crystalline form is designated as Form C.



DESCRIPTION OF THE DRAWINGS
FIG. 1 is the X-ray diffraction pattern of Form A0 prepared by using ethanol as the second organic solvent.
FIG. 2 is the X-ray diffraction pattern of Form A1 prepared by using methanol as the second organic solvent.
FIG. 3 is the X-ray diffraction pattern of Form B0 prepared by using isopropanol as the second organic solvent.
FIG. 4 is the X-ray diffraction pattern of Form B1 prepared by using acetone as the second organic solvent.
FIG. 5 is the X-ray diffraction pattern of Form B2 prepared by using dichloromethane as the second organic solvent.
FIG. 6 is the X-ray diffraction pattern of Form B3 prepared by using ethyl acetate as the second organic solvent.
FIG. 7 is the X-ray diffraction pattern of Form C prepared by using glycol as the second organic solvent.
FIG. 8 is the TG-DTA chart of Form A0 prepared by using ethanol as the second organic solvent.
FIG. 9 is the TG-DTA chart of Form A1 prepared by using methanol as the second organic solvent.
FIG. 10 is the TG-DTA chart of Form B0 prepared by using isopropanol as the second organic solvent.
FIG. 11 is the TG-DTA chart of Form B1 prepared by using acetone as the second organic solvent.
FIG. 12 is the TG-DTA chart of Form B2 prepared by using dichloromethane as the second organic solvent.
FIG. 13 is the TG-DTA chart of Form B3 prepared by using ethyl acetate as the second organic solvent.
FIG. 14 is the TG-DTA chart of Form C prepared by using glycol as the second organic solvent.
FIG. 15 is the infrared absorption spectrum of Form A0 prepared by using ethanol as the second organic solvent.
FIG. 16 is the infrared absorption spectrum of Form A1 prepared by using methanol as the second organic solvent.
FIG. 17 is the infrared absorption spectrum of Form B0 prepared by using isopropanol as the second organic solvent.
FIG. 18 is the infrared absorption spectrum of Form B1 prepared by using acetone as the second organic solvent.
FIG. 19 is the infrared absorption spectrum of Form B2 prepared by using dichloromethane as the second organic solvent.
FIG. 20 is the infrared absorption spectrum of Form B3 prepared by using ethyl acetate as the second organic solvent.
FIG. 21 is the infrared absorption spectrum of Form C prepared by using glycol as the second organic solvent.



MODE OF CARRYING OUT THE INVENTION
The following specific parameters are used to describe various crystalline forms of the present invention. In the present invention, X-ray Powder Diffraction (XRPD), Thermo gravimetry-Differential Thermal Analysis (TG-DTA) and Infra-Red (IR) measurement conditions are presented as follows:
XRPD:
Apparatus: Savitzkey-Golay type X-ray Diffractometer, test conditions: 40 kv 100 mA;
Slit: DS/SS=1°, RS=0.3 mm; Step: 0.02; target type: copper target, 1.5405 Å; Range: 3-50°; scan rate: 8°/min.
TG-DTA:
Apparatus: Rigaku PTC-10A TG-DTA analyzer; range: 7 mg;
Temperature range: room temperature-300° C.; heating rate: 10° C./min; DTA range: ±25 μv.
IR:
Apparatus: SHIMADZU FTIR-8400S FT/IR type infrared spectroscopy, wave number was corrected by infrared absorption peak of polystyrene film; Method: KBr tablet method, recording spectrum in a range of 4000-400 cm−1.
In one embodiment of the present invention, when the second organic solvent is ethanol, the obtained crystalline form of Temozolomide is named as Form A0 type, characterized by powder X-ray diffraction spectrum comprising characteristic diffraction peaks expressed in terms of 2θ at 10.74±0.2, 14.54±0.2, 26.40±0.2, 28.66±0.2 and 29.74±0.2. Specific X-ray diffraction data are shown in Table 1 and the X-ray diffraction pattern is shown in FIG. 1.







TABLE 1







Characteristic peak parameters of X-ray diffraction pattern of Form A0












Nos.
2θ
d value
Relative intensity I/I0
















1
5.320
16.5976
3



2
10.740
8.2306
49



3
13.060
6.7733
4



4
14.040
6.3026
6



5
14.540
6.0870
100



6
16.180
5.4735
15



7
16.660
5.3169
7



8
17.520
5.0578
4



9
17.880
4.9568
15



10
19.000
4.6670
15



11
19.480
4.5531
5



12
20.580
4.3121
4



13
21.260
4.1757
9



14
21.500
4.1297
14



15
23.640
3.7604
10



16
25.120
3.5421
5



17
26.400
3.3732
31



18
27.060
3.2924
5



19
27.640
3.2247
6



20
28.660
3.1122
33



21
29.440
3.0315
10



22
29.740
3.0016
20



23
30.220
2.9550
8



24
32.200
2.7776
8



25
32.520
2.7510
8



26
33.300
2.6884
4



27
34.460
2.6005
3



28
35.600
2.5198
6



29
36.140
2.4833
4



30
38.220
2.3528
4



31
39.580
2.2751
5



32
40.780
2.2109
4



33
41.740
2.1622
4



34
43.380
2.0842
5



35
44.260
2.0448
9



36
47.700
1.9050
5



37
48.600
1.8718
4










As shown in TG-DTA spectrum, Form A0 has an exothermic peak at 206° C. (FIG. 8).
As shown in the infrared absorption spectrum data, Form A0 has characteristic absorption peaks at 3423.41, 3388.70, 3114.82, 1755.10, 1728.10, 1681.81, 1452.30, 1265.22 and 948.91 cm−1 (FIG. 15).
In another embodiment of the present invention, when the second organic solvent is methanol, the resultant crystalline form of Temozolomide is named as Form A1, characterized by powder X-ray diffraction spectrum comprising characteristic diffraction peaks expressed in terms of 2θ at 10.72±0.2, 14.58±0.2, 17.90±0.2, 26.44±0.2 and 28.68±0.2. Specific X-ray diffraction data are shown in Table 2, and the X-ray diffraction pattern is shown in FIG. 2.







TABLE 2







Characteristic peak parameters of X-ray diffraction pattern of Form A1












Nos.
2θ
d value
Relative intensity I/I0
















1
7.420
11.9042
2



2
10.720
8.2459
10



3
13.260
6.6716
4



4
14.100
6.2759
6



5
14.580
6.0704
100



6
16.180
5.4735
4



7
16.680
5.3106
4



8
17.560
5.0464
2



9
17.900
4.9513
12



10
18.980
4.6719
7



11
19.480
4.5531
2



12
20.580
4.3121
2



13
21.300
4.1680
5



14
21.520
4.1259
5



15
22.120
4.0153
1



16
23.660
3.7573
5



17
25.120
3.5421
3



18
26.200
3.3985
8



19
26.440
3.3682
17



20
27.100
3.2877
3



21
27.640
3.2247
4



22
28.680
3.1100
15



23
29.480
3.0274
9



24
29.780
2.9976
8



25
30.220
2.9550
5



26
31.340
2.8519
3



27
32.240
2.7743
4



28
32.540
2.7494
3



29
33.360
2.6837
2



30
34.500
2.5975
2



31
35.620
2.5184
3



32
36.160
2.4820
2



33
39.580
2.2751
2



34
40.800
2.2098
2



35
41.760
2.1612
2



36
43.060
2.0989
2



37
47.700
1.9050
3










As shown in TG-DTA spectrum, Form A1 has an exothermic peak at 202° C. (FIG. 9).
As shown in infrared absorption spectrum data, Form A1 has characteristic absorption peaks at 3423.41, 3388.70, 3112.89, 1755.10, 1728.10, 1674.10, 1452.30, 1265.22 and 948.91 cm−1 (FIG. 16).
By comparing the powder X-ray diffraction data, TG-DTA data and infrared absorption data between Form A0 and Form A1, it can be identified that both ones should be the same crystalline form, which is totally referred to as crystalline Form A.
In another embodiment of the present invention, when the second organic solvent is isopropanol, the resultant crystalline form of Temozolomide is named as Form B0, characterized by powder X-ray diffraction spectrum comprising characteristic diffraction peaks expressed in terms of 2θ at 7.34±0.2, 14.70±0.2, 22.98±0.2, 23.82±0.2 and 28.10±0.2. Specific X-ray diffraction data are shown in Table 3 and the X-ray diffraction pattern is shown in FIG. 3.







TABLE 3







Characteristic peak parameters of X-ray diffraction pattern of Form B0












Nos.
2θ
d value
Relative intensity I/I0
















1
7.340
12.0338
92



2
10.800
8.1850
3



3
12.740
6.9427
2



4
14.020
6.3116
19



5
14.700
6.0211
100



6
16.080
5.5073
2



7
17.580
5.0407
3



8
17.920
4.9458
2



9
18.900
4.6915
6



10
19.440
4.5624
9



11
20.640
4.2997
2



12
22.160
4.0081
9



13
22.560
3.9380
4



14
22.980
3.8669
15



15
23.820
3.7324
25



16
24.420
3.6421
5



17
25.940
3.4320
11



18
26.480
3.3632
4



19
28.100
3.1729
24



20
28.740
3.1037
4



21
29.440
3.0315
5



22
29.760
2.9996
5



23
31.000
2.8824
12



24
32.920
2.7185
6



25
33.480
2.6743
9



26
34.000
2.6346
3



27
35.620
2.5184
3



28
37.360
2.4050
11



29
37.980
2.3672
3



30
40.300
2.2361
4



31
45.520
1.9910
8



32
47.480
1.9133
5



33
47.940
1.8960
4



34
48.340
1.8813
4



35
48.780
1.8653
4










As shown in TG-DTA spectrum, Form B0 has an exothermic peak at 203° C. (FIG. 10).
As shown in infrared absorption spectrum data, Form B0 is characterized in that it has characteristic absorption peaks at 3388.70, 3114.82, 1758.96, 1681.81, 1452.30, 1265.22, 950.84 and 736.76 cm−1 (FIG. 17).
In another embodiment of the present invention, when the second organic solvent is acetone, the resultant crystalline form of Temozolomide is named as Form B1, characterized by powder X-ray diffraction spectrum comprising characteristic peaks expressed in terms of 2θ at 7.30±0.2, 14.70±0.2, 18.88±0.2, 23.76±0.2, 28.06±0.2 and 29.42±0.2. Specific X-ray diffraction data are shown in Table 4 and the X-ray diffraction pattern is shown in FIG. 4.







TABLE 4







Characteristic peak parameters of X-ray diffraction pattern of Form B1












Nos.
2θ
d value
Relative intensity I/I0
















1
7.300
12.0996
100



2
10.740
8.2306
5



3
11.120
7.9502
3



4
12.680
6.9754
5



5
13.940
6.3476
30



6
14.700
6.0211
78



7
16.080
5.5073
3



8
17.600
5.0350
11



9
17.900
4.9513
4



10
18.880
4.6964
44



11
19.360
4.5810
19



12
20.000
4.4359
7



13
20.660
4.2956
9



14
22.140
4.0117
7



15
22.500
3.9483
11



16
22.880
3.8836
42



17
23.760
3.7417
75



18
24.340
3.6539
12



19
25.860
3.4424
10



20
26.380
3.3757
8



21
27.140
3.2829
4



22
28.060
3.1773
69



23
28.680
3.1100
12



24
29.420
3.0335
44



25
30.960
2.8860
32



26
31.500
2.8378
4



27
32.840
2.7250
6



28
33.140
2.7010
10



29
33.380
2.6821
18



30
33.900
2.6421
7



31
34.540
2.5946
5



32
35.560
2.5225
5



33
37.340
2.4062
10



34
37.640
2.3878
5



35
39.320
2.2895
4



36
40.220
2.2403
6



37
40.800
2.2098
4



38
41.820
2.1582
5



39
42.960
2.1036
5



40
43.540
2.0769
4



41
44.640
2.0282
4



42
45.420
1.9952
6



43
47.400
1.9164
7



44
48.280
1.8835
6



45
48.720
1.8675
5










As shown in TG-DTA spectrum, Form B1 has an exothermic peak at 202° C. (FIG. 11).
As shown in infrared absorption spectrum data, Form B1 has characteristic absorption peaks at 3388.70, 3114.82, 1758.96, 1728.10, 1681.81, 1452.30, 1265.22, 952.77 and 736.76 cm−1 (FIG. 18).
In another embodiment of the present invention, when the second organic solvent is dichloromethane, the resultant crystalline form of Temozolomide is named as Form B2, characterized by powder X-ray diffraction spectrum comprising characteristic peaks expressed in terms of 2θ at 7.32±0.2, 14.02±0.2, 14.70±0.2, 22.94±0.2 and 23.78±0.2. Specific X-ray diffraction data are shown in Table 5 and the X-ray diffraction pattern is shown in FIG. 5.







TABLE 5







Characteristic peak parameters of X-ray diffraction pattern of Form B2












Nos.
2θ
d value
Relative intensity I/I0
















1
7.320
12.0666
100



2
10.620
8.3234
1



3
12.720
6.9536
2



4
14.020
6.3116
14



5
14.700
6.0211
99



6
17.580
5.0407
3



7
18.900
4.6915
4



8
19.380
4.5764
6



9
22.120
4.0153
8



10
22.940
3.8736
11



11
23.780
3.7386
24



12
24.400
3.6450
5



13
25.880
3.4398
9



14
28.120
3.1707
7



15
29.500
3.0254
4



16
29.880
2.9878
5



17
30.960
2.8860
10



18
32.920
2.7185
7



19
33.420
2.6790
8



20
33.920
2.6406
2



21
35.580
2.5211
2



22
37.340
2.4062
10



23
37.940
2.3696
4



24
40.260
2.2382
3



25
42.880
2.1073
2



26
45.500
1.9919
6



27
47.440
1.9148
4



28
47.920
1.8968
4



29
48.280
1.8835
4



30
48.760
1.8661
3










As shown in TG-DTA spectrum, Form B2 has an exothermic peak at 205° C. (FIG. 12).
As shown in infrared absorption spectrum data, Form B2 has characteristic absorption peaks at 3388.70, 3114.82, 1758.96, 1735.81, 1731.96, 1677.95, 1452.30, 1265.22, 952.77 and 736.76 cm−1 (FIG. 19).
In another embodiment of the present invention, when the second organic solvent is ethyl acetate, the resultant crystalline form of Temozolomide is named as Form B3, characterized by powder X-ray diffraction spectrum comprising characteristic peaks expressed in terms of 2θ at 7.36±0.2, 14.06±0.2, 14.74±0.2, 23.00±0.2 and 23.86±0.2. Specific X-ray diffraction data are shown in Table 6 and the X-ray diffraction pattern is shown in FIG. 6.







TABLE 6







Characteristic peak parameters of X-ray diffraction pattern of Form B3












Nos.
2θ
d value
Relative intensity I/I0
















1
7.360
12.0011
100



2
11.200
7.8936
2



3
12.780
6.9210
3



4
14.060
6.2937
38



5
14.740
6.0049
93



6
16.120
5.4938
3



7
17.640
5.0237
5



8
18.940
4.6817
13



9
19.460
4.5577
13



10
20.080
4.4184
3



11
20.740
4.2792
3



12
22.180
4.0046
7



13
22.580
3.9345
6



14
23.000
3.8636
27



15
23.860
3.7263
38



16
24.500
3.6304
8



17
25.940
3.4320
12



18
26.560
3.3533
2



19
28.180
3.1641
21



20
28.800
3.0974
4



21
29.520
3.0234
8



22
31.040
2.8788
18



23
32.960
2.7153
6



24
33.480
2.6743
10



25
34.020
2.6331
3



26
35.660
2.5157
3



27
37.380
2.4038
7



28
37.980
2.3672
3



29
40.320
2.2350
4



30
44.640
2.0282
2



31
45.520
1.9910
5



32
47.480
1.9133
5



33
48.360
1.8805
4



34
48.800
1.8646
4










As shown in TG-DTA spectrum, Form B3 has an exothermic peak at 200° C. (FIG. 13).
As shown in infrared absorption spectrum data, Form B3 has characteristic absorption peaks at 3388.70, 3114.82, 1751.24, 1735.81, 1728.10, 1674.10, 1452.30, 1265.22, 952.77, 730.97 and 711.68 cm−1 (FIG. 20).
By comparing the powder X-ray diffraction, TG-DTA data and infrared absorption data of B0, B1, B2 and B3 crystalline forms, it can be identified that these four ones should be the same crystalline form, which is totally referred to as crystalline Form B.
In another embodiment of the present invention, when the second organic solvent is glycol, the resultant crystalline form of Temozolomide is named as Form C, characterized by powder X-ray diffraction spectrum comprising characteristic peaks expressed in terms of 2θ at 11.46±0.2, 13.20±0.2, 19.64±0.2, 24.58±0.2 and 28.80±0.2. Specific X-ray diffraction data are shown in Table 7 and the X-ray diffraction pattern is shown in FIG. 7.







TABLE 7







Characteristic peak parameters of X-ray diffraction pattern of Form C












Nos.
2θ
d value
Relative intensity I/I0
















1
10.860
8.1400
7



2
11.460
7.7151
100



3
12.140
7.2844
7



4
13.200
6.7018
19



5
14.680
6.0293
17



6
15.420
5.7415
4



7
16.260
5.4468
3



8
16.740
5.2917
2



9
17.120
5.1751
3



10
18.040
4.9132
6



11
19.100
4.6428
4



12
19.640
4.5164
22



13
21.540
4.1221
10



14
23.020
3.8603
14



15
23.900
3.7201
9



16
24.580
3.6187
23



17
25.400
3.5037
4



18
26.520
3.3582
10



19
26.860
3.3165
14



20
27.800
3.2065
6



21
28.800
3.0974
20



22
29.980
2.9781
9



23
30.900
2.8915
15



24
31.140
2.8697
10



25
31.480
2.8395
7



26
32.100
2.7861
7



27
33.600
2.6650
3



28
37.940
2.3696
4



29
38.600
2.3306
5



30
39.620
2.2729
3



31
41.340
2.1822
10



32
43.320
2.0869
4



33
43.580
2.0751
9



34
46.380
1.9561
4



35
46.920
1.9349
15



36
49.780
1.8302
5










As shown in TG-DTA spectrum, Form C has an exothermic peak at 201° C. (FIG. 14).
As shown in infrared absorption spectrum data, Form C has characteristic absorption peaks at 3388.70, 3112.89, 1758.96, 1731.96, 1674.10, 1454.23, 1267.14, 950.84, 736.76 and 698.18 cm−1 (FIG. 21).
According to the second aspect, the present invention also provides a pharmaceutical composition, particularly a solid pharmaceutical composition, and the pharmaceutical composition contains any one of the crystalline forms of Temozolomide of the present invention.
The API of the pharmaceutical composition is any one of the crystalline forms of Temozolomide of the present invention, and its percentage by weight in the preparations may be 0.01-99.99%, and the balanced is pharmaceutically acceptable carrier(s).
Preferably, the solid pharmaceutical composition of the present invention is solid pharmaceutical compositions for oral administration, such as tablets, capsules, granules, pills, dry powders and the like.
The usage and dosage of the pharmaceutical compositions are determined by the patient's conditions, e.g. 1-3 times per day.
Compared with the prior art, the present invention has the following advantages:

    (1) Improved yield rate: since DMSO belongs to an aprotic polar solvent, and Temozolomide has a large solubility in DMSO, only a small amount of the solvent is needed for purification. Addition of the second organic solvent can improve product yield rate greatly.
    (2) Increased purity: the organic impurities in Temozolomide have a high solubility in the second organic solvent and DSMO, especially the colored allergic impurities which are difficult to be removed by other solvents can be eliminated. Thus, the product purity increases significantly.
    (3) Purity and stability of the crystalline forms of Temozolomide prepared by the method of the present invention are better than those in the prior art.


The advantages of the present invention are presented by the following experimental data:
I. Solubility Test
It should be noted that each crystalline form of Form A, Form B and Form C has similar solubility properties. Hereinafter, Form A0, B0 and C were chosen only for illustrative purpose.
1. Solubility test of the crystalline Form A of Temozolomide (Form A0 prepared by the method of EXAMPLE 1). Solubility properties were assayed respectively by using DMSO, methanol, water, glacial acetic acid, 0.1M HCl, 0.1M NaOH and ethanol as the solvents. The results are shown in Table 8.







TABLE 8







Results of solubility test of crystalline Form A of Temozolomide













Amount of
Amount of





solvent
solvent for




Tested
for dissolving
dissolving



drug
tested
1 g of tested


Solvents
(mg)
drug (ml)
drug (ml)
Solubility














DMSO
10.10
0.7
70
sparingly






soluble


Methanol
9.98
7.0
700
Slightly soluble


Water
9.84
8.0
800
Slightly soluble


Glacial acetic
10.09
3.0
300
Slightly soluble


acid


0.1M HCl
10.13
7
700
Slightly soluble


0.1M NaOH
9.95
3
300
Slightly soluble


Ethanol
10.03
55
5500
Very slightly






soluble









2. Solubility test of the crystalline form B of Temozolomide (Form B0 prepared by the method of EXAMPLE 6). Solubility properties were assayed respectively by using DMSO, methanol, water, glacial acetic acid, 0.1M HCl, 0.1M NaOH and ethanol as the solvents. The results are shown in Table 9.







TABLE 9







Results of solubility test of crystalline Form B of Temozolomide













Amount of
Amount of





solvent
solvent for




Tested
for dissolving
dissolving



drug
tested
1 g of tested


Solvents
(mg)
drug (ml)
drug (ml)
Solubility














DMSO
10.07
0.6
70
sparingly






soluble


Methanol
9.89
9.0
900
Slightly soluble


Water
10.02
8.0
800
Slightly soluble


Glacial
9.99
3.0
300
Slightly soluble


acetic acid


0.1M HCl
9.93
8
800
Slightly soluble


0.1M NaOH
10.05
3
300
Slightly soluble


Ethanol
10.13
57
5700
Very slightly






soluble









3. Solubility test of the crystalline form C of Temozolomide (Form C prepared by the method of EXAMPLE 14). Solubility properties were assayed respectively by using DMSO, methanol, water, glacial acetic acid, 0.1M HCl, 0.1M NaOH and ethanol as the solvents. The results are shown in Table 10.







TABLE 10







Results of solubility test of crystalline Form C of Temozolomide













Amount of
Amount of





solvent
solvent for




Tested
for dissolving
dissolving



drug
tested
1 g of tested


Solvents
(mg)
drug (ml)
drug (ml)
Solubility














DMSO
9.95
0.8
80
sparingly






soluble


Methanol
9.91
8.0
800
Slightly soluble


Water
10.08
8.0
800
Slightly soluble


Glacial
10.21
3.0
300
Slightly soluble


acetic acid


0.1M HCl
10.11
8.0
800
Slightly soluble


0.1M NaOH
9.97
3.0
300
Slightly soluble


Ethanol
10.17
60
6000
Very slightly






soluble









II. Stability Test

In the following test, related substances were determined as follows: HPLC method was used and chromatographic conditions were as follows: C18 column using octadecylsilane bonded silica gel as the filler, isocratic elution using methanol: 0.5% glacial acetic acid solution (10:90) as the mobile phase, and detection wavelength was at 254 nm.
It should be noted that each crystalline form of Form A, Form B and Form C has similar stability properties. Hereinafter, Form A0, Form B0 and Form C were chosen only for illustrative purpose.
1. Stability of Crystalline Form A of Temozolomide
1.1 Light Exposure Test
Crystalline form A of Temozolomide (Form A0 prepared by the method of EXAMPLE 1) was exposed under conditions of light intensity of 4500±500Lx, sampled and determined on the 5th and 10th day. The results are shown in Table 11.







TABLE 11







Results of crystalline Form A of Temozolomide in the strong light


exposure test











Time
Appearance and
Drying loss
Content
Related


(day)
color
(%)
(%)
substances














0th day
White powder
0.35
99.94
Not detected


5th day
White powder
0.33
99.93
Not detected


10th day 
White powder
0.39
99.81
Not detected









1.2 High Temperature Test

Crystalline form A of Temozolomide (Form A0 prepared by the method of EXAMPLE 1) was placed in 60° C. incubator, sampled and determined on the 5th and 10th day. The results are shown in Table 12.







TABLE 12







Results of crystalline Form A of Temozolomide


in the high temperature test











Time
Appearance
Drying loss
Content
Related


(day)
and color
(%)
(%)
substances





0th day
White powder
0.41
99.94
Not detected


5th day
White powder
0.38
99.63
Not detected


10th day 
White powder
0.34
99.31
Not detected









1.3 High Humidity Test

Crystalline Form A of Temozolomide (Form A0 prepared by the method of EXAMPLE 1) was placed in 25° C. incubator (relative humidity: 75±5%), sampled and determined on the 5th and 10th day. The results are shown in Table 13.







TABLE 13







Results of crystalline Form A of Temozolomide


in the high humidity test













Weight gain




Time
Appearance
of moisture
Content
Related


(day)
and color
absorption (%)
(%)
substances














0th day
White powder
0
99.94
Not detected


5th day
White powder
0.32
99.73
Not detected


10th day 
White powder
0.51
99.52
Not detected









1.4 Accelerated Test

Crystalline Form A of Temozolomide (Form A0 prepared by the method of EXAMPLE 1) was sealed by a polyethylene film bag, placed under conditions of 40±2° C. and a relative humidity of 75±5% for 6 months, sampled and determined at the end of the 1st,2nd, 3rd and 6th month. The results are shown in Table 14.







TABLE 14







Results of crystalline Form A of Temozolomide


in the accelerated test













Appearance
Content
Related



Time
and color
(%)
substances















0th
month
White powder
99.94
Not detected


1st
month
White powder
99.81
Not detected


2nd
month
White powder
99.64
Not detected


3rd
month
White powder
99.92
Not detected


6th
month
White powder
99.62
Not detected









As shown in the results, crystalline Form A of Temozolomide was stable in the light exposure test, the high-temperature test, the high-humidity test and the accelerated test, and there was no obvious change in the appearance and color, the drying loss, the content and the related substances. The weight gain of moisture absorption slightly increased under the high-humidity condition.
2. Stability of Crystalline Form B of Temozolomide
2.1 Light Exposure Test
Crystalline form B of Temozolomide (Form B0 prepared by the method of EXAMPLE 6) was placed, exposed under conditions of light intensity of 4500±500Lx, sampled and determined on the 5th and 10th day. The results are shown in Table 15.







TABLE 15







Results of crystalline Form B of Temozolomide


in the strong light exposure test











Time
Appearance
Drying loss
Content
Related


(day)
and color
(%)
(%)
substances





0th day
White powder
0.38
99.97
Not detected


5th day
White powder
0.33
99.92
Not detected


10th day 
White powder
0.29
99.95
Not detected









2.2 High Temperature Test

Crystalline Form B of Temozolomide (Form B0 prepared by the method of EXAMPLE 6) was placed in 60° C. incubator, sampled and determined on the 5th and 10th day. The results are shown in Table 16.







TABLE 16







Results of crystalline Form B of Temozolomide


in the high temperature test











Time
Appearance
Drying loss
Content
Related


(day)
and color
(%)
(%)
substances





0th day
White powder
0.33
99.97
Not detected


5th day
White powder
0.27
99.73
Not detected


10th day 
White powder
0.29
99.61
Not detected









2.3 High Humidity Test

Crystalline Form B of Temozolomide (Form B0 prepared by the method of EXAMPLE 6) was placed in 25° C. incubator (relative humidity: 75±5%), sampled and determined on the 5th and 10th day. The results are shown in Table 17.







TABLE 17







Results of crystalline Form B of Temozolomide


in the high humidity test













Weight gain




Time
Appearance
of moisture
Content
Related


(day)
and color
absorption (%)
(%)
substances














0th day
White powder
0
99.97
Not detected


5th day
White powder
0.37
99.63
Not detected


10th day 
White powder
0.52
99.57
Not detected









2.4 Accelerated Test

Crystalline Form B of Temozolomide (Form B0 prepared by the method of EXAMPLE 6) was sealed with a polyethylene film bag and placed under conditions of 40±2° C. and a relative humidity of 75±5% for 6 months, sampled and determined at the end of the 1st, 2nd, 3rd and 6th month. The results are shown in Table 18.







TABLE 18







Results of crystalline Form B of Temozolomide


in the accelerated test













Appearance
Content
Related



Time
and color
(%)
substances















0th
month
White powder
99.97
Not detected


1st
month
White powder
99.71
Not detected


2nd
month
White powder
99.82
Not detected


3rd
month
White powder
99.73
Not detected


6th
month
White powder
99.85
Not detected









As shown in the results, crystalline Form B of Temozolomide was stable in the light exposure test, the high-temperature, the high-humidity test and the accelerated test, and there was no obvious change in the appearance and color, the drying loss, the content and the related substances. The weight gain of moisture absorption slightly increased under the high-humidity condition.
3. Stability of Crystalline Form C of Temozolomide
3.1 Light Exposure Test
Crystalline Form C of Temozolomide (Form C prepared by the method of EXAMPLE 14) was placed, exposed under conditions of light intensity of 4500±500Lx, sampled and determined on the 5th and 10th day. The results are shown in Table 19.







TABLE 19







Results of crystalline Form C of Temozolomide


in the strong light exposure test











Time
Appearance
Drying loss
Content
Related


(day)
and color
(%)
(%)
substances





0th day
White powder
0.27
99.91
Not detected


5th day
White powder
0.30
99.90
Not detected


10th day 
White powder
0.32
99.96
Not detected









3.2 High Temperature Test

Crystalline Form C of Temozolomide (Form C prepared by the method of EXAMPLE 14) was placed in 60° C. incubator, sampled and determined on the 5th and 10th day. The results are shown in Table 20.







TABLE 20







Results of crystalline Form C of Temozolomide


in the high temperature test











Time
Appearance
Drying loss
Content
Related


(day)
and color
(%)
(%)
substances





0th day
White powder
0.35
99.91
Not detected


5th day
White powder
0.37
99.79
Not detected


10th day 
White powder
0.34
99.69
Not detected









3.3 High Humidity Test

Crystalline Form C of Temozolomide (Form C prepared by the method of EXAMPLE 14) was placed in 25° C. incubator (relative humidity: 75±5%), sampled and determined on the 5th and 10th day. The results are shown in Table 21.







TABLE 21







Results of crystalline Form C of Temozolomide


in the high humidity test













Weight gain




Time
Appearance
of moisture
Content
Related


(day)
and color
absorption (%)
(%)
substances














0th day
White powder
0
99.91
Not detected


5th day
White powder
0.29
99.85
Not detected


10th day 
White powder
0.47
99.63
Not detected









3.4 Accelerated Test

Crystalline Form C of Temozolomide (Form C prepared by the method of EXAMPLE 14) was sealed with a polyethylene film bag and placed under conditions of 40±2° C. and a relative humidity of 75±5% for 6 months, sampled and determined at the end of the 1st, 2nd, 3rd and 6th month. The results are shown in Table 22.







TABLE 22







Results of crystalline Form C of Temozolomide


in the accelerated test













Appearance
Content
Related



Time
and color
(%)
substances















0th
month
White powder
99.91
Not detected


1st
month
White powder
99.61
Not detected


2nd
month
White powder
99.87
Not detected


3rd
month
White powder
99.93
Not detected


6th
month
White powder
99.65
Not detected









As shown in the results, crystalline Form C of Temozolomide was stable in the light exposure test, the high-temperature, the high-humidity test and the accelerated test, and there was no obvious change in the appearance and color, the drying loss, the content and the related substances. The weight gain of moisture absorption slightly increased under the high-humidity condition.
EXAMPLES
The following examples were used to further illustrate the present invention. The method in the examples of the present invention are merely illustrative of the present invention and are not intended to limit the present invention.
Example 1
Preparation of Crystalline Form A of Temozolomide
20 g of Temozolomide was placed into a reaction bottle, into which 200 ml of DMSO was added, the mixture of Temozolomide and DMSO was stirred and heated to 80° C. to make the Temozolomide dissolved. 300 ml of ethanol was added, stirred for 5 min and cooled down to 10-15° C., crystallized for 4 hours by stirring to give the crystalline form. The resultant crystalline form was filtered, washed with 40 ml of ethanol and dried for 4 hours in vacuum (vacuum degree≦−0.07 Mpa) at 45-50° C. to obtain crystalline Form A0 of Temozolomide (16.4 g). The yield rate was 82%.
Example 2
Preparation of Crystalline Form A of Temozolomide
20 g of Temozolomide was placed into a reaction bottle, into which 140 ml of DMSO was added, the mixture of Temozolomide and DMSO was stirred and heated to 140° C. to make the Temozolomide dissolved. 140 ml of ethanol was added, stirred for 5 min and cooled down to 10-15° C., crystallized for 4 hours by stirring to give the crystalline form. The resultant crystalline form was filtered, washed with 60 ml of ethanol and dried for 4 hours in vacuum (vacuum degree≦−0.07 Mpa) at 45-50° C. to obtain crystalline Form A0 of Temozolomide (16.0 g). The yield rate was 80%.
Example 3
Preparation of Crystalline Form A of Temozolomide
20 g of Temozolomide was placed into a reaction bottle, into which 300 ml of DMSO was added, the mixture of Temozolomide and DMSO was stirred and heated to 60° C. to make the Temozolomide dissolved. 400 ml of ethanol was added, stirred for 5 min and cooled down to 10-15° C., crystallized for 4 hours by stirring to give the crystalline form. The resultant crystalline form was filtered, washed with 100 ml of ethanol and dried for 4 hours in vacuum (vacuum degrees≦−0.07 Mpa) at 45-50° C. to obtain crystalline Form A0 of Temozolomide (16.6 g). The yield rate was 83%.
Example 4
Preparation of Crystalline Form A of Temozolomide
20 g of Temozolomide was placed into a reaction bottle, into which 140 ml of DMSO was added, the mixture of Temozolomide and DMSO was stirred and heated to 120° C. to make the Temozolomide dissolved. 100 ml of methanol was added, stirred for 10 min and cooled down to 10-15° C., crystallized for 4 hours by stirring to give the crystalline form. The resultant crystalline form was filtered, washed with 40 ml of methanol and dried for 4 hours in vacuum (vacuum degree≦−0.07 Mpa) at 45-50° C. to obtain crystalline Form A1 of Temozolomide (16.7 g). The yield rate was 83.5%.
Example 5
Preparation of Crystalline Form A of Temozolomide
20 g of Temozolomide was placed into a reaction bottle, into which 160 ml of DMSO was added, the mixture of Temozolomide and DMSO was stirred and heated to 110° C. to make the Temozolomide dissolved. 140 ml of methanol was added, stirred for 10 min and cooled down to 10-15° C., crystallized for 4 hours by stirring to give the crystalline form. The resultant crystalline form was filtered, washed with 60 ml of methanol and dried for 4 hours in vacuum (vacuum degree≦−0.07 Mpa) at 45-50° C. to obtain crystalline Form A1 of Temozolomide (16.0 g). The yield rate was 80%.
Example 6
Preparation of Crystalline Form B of Temozolomide
10 g of Temozolomide was placed into a reaction bottle, into which 80 ml of DMSO was added, the mixture of Temozolomide and DMSO was stirred and heated to 110° C. to make the Temozolomide dissolved. 200 ml of isopropanol was added, stirred for 5 min and cooled down to 10-15° C., crystallized for 4 hours by stirring to give the crystalline form. The resultant crystalline form was filtered, washed with 30 ml of isopropanol and dried for 4 hours in vacuum (vacuum degrees≦−0.07 Mpa) at 45-50° C. to obtain crystalline Form B0 of Temozolomide (9.45 g). The yield rate was 94.5%.
Example 7
Preparation of Crystalline Form B of Temozolomide
10 g of Temozolomide was placed into a reaction bottle, into which 110 ml of DMSO was added, the mixture of Temozolomide and DMSO was stirred and heated to 80° C. to make the Temozolomide dissolved. 300 ml of isopropanol was added, stirred for 5 min and cooled down to 10-15° C., crystallized for 4 hours by stirring to give the crystalline form. The resultant crystalline form was filtered, washed with 20 ml of isopropanol and dried for 4 hours in vacuum (vacuum degree≦−0.07 Mpa) at 45-50° C. to obtain crystalline Form B0 of Temozolomide (9.21 g). The yield rate was 92.1%.
Example 8
Preparation of Crystalline Form B of Temozolomide
5 g of Temozolomide was placed into a reaction bottle, into which 100 ml of DMSO was added, the mixture of Temozolomide and DMSO was stirred and heated to 60° C. to make the Temozolomide dissolved. 150 ml of acetone was added, stirred for 5 min and cooled down to 10-15° C., crystallized for 4 hours by stirring to give the crystalline form. The resultant crystalline form was filtered, washed with 50 ml of acetone and dried for 4 hours in vacuum (vacuum degree≦−0.07 Mpa) at 45-50° C. to obtain crystalline Form B1 of Temozolomide (4.1 g). The yield rate was 82%.
Example 9
Preparation of Crystalline Form B of Temozolomide
5 g of Temozolomide was placed into a reaction bottle, into which 60 ml DMSO was added, the mixture of Temozolomide and DMSO was stirred and heated to 70° C. to make the Temozolomide dissolved. 100 ml of acetone was added, stirred for 5 min and cooled down to 10-15° C., crystallized for 4 hours by stirring to give the crystalline form. The resultant crystalline form was filtered, washed with 40 ml of acetone and dried for 4 hours in vacuum (vacuum degree≦−0.07 Mpa) at 45-50° C. to obtain crystalline Form B1 of Temozolomide (4.0 g). The yield rate was 80%.
Example 10
Preparation of Crystalline Form B of Temozolomide
20 g of Temozolomide was placed into a reaction bottle, into which 250 ml of DMSO was added, the mixture of Temozolomide and DMSO was stirred and heated to 80° C. to make the Temozolomide dissolved. 300 ml of dichloromethane was added, stirred for 5 min and cooled down to 10-15° C., crystallized for 4 hours by stirring to give the crystalline form. The resultant crystalline form was filtered, washed with 50 ml of dichloromethane and dried for 4 hours in vacuum (vacuum degree≦−0.07 Mpa) at 45-50° C. to obtain crystalline Form B2 of Temozolomide (19.1 g). The yield rate was 95.5%.
Example 11
Preparation of Crystalline Form B of Temozolomide
20 g of Temozolomide was placed into a reaction bottle, into which 200 ml of DMSO was added, the mixture of Temozolomide and DMSO was stirred and heated to 80° C. to make the Temozolomide dissolved. 250 ml of dichloromethane was added, stirred for 5 min and cooled down to 10-15° C., crystallized for 4 hours by stirring to give the crystalline form. The resultant crystalline form was filtered, washed with 60 ml of dichloromethane and dried for 4 hours in vacuum (vacuum degrees≦−0.07 Mpa) at 45-50° C. to obtain crystalline Form B2 of Temozolomide (19.0 g). The yield rate was 95%.
Example 12
Preparation of Crystalline Form B of Temozolomide
10 g of Temozolomide was placed into a reaction bottle, into which 80 ml of DMSO was added, the mixture of Temozolomide and DMSO was stirred and heated to 130° C. to make the Temozolomide dissolved. 200 ml of ethyl acetate was added, stirred for 5min and cooled down to 10-15° C., crystallized for 4 hours by stirring to give the crystalline form. The resultant crystalline form was filtered, washed with 50 ml of ethyl acetate and dried for 4 hours in vacuum (vacuum degree≦−0.07 Mpa) at 45-50° C. to obtain crystalline Form B3 of Temozolomide (8.2 g). The yield rate was 82%.
Example 13
Preparation of Crystalline Form B of Temozolomide
10 g of Temozolomide was placed into a reaction bottle, into which 90 ml of DMSO was added, the mixture of Temozolomide and DMSO was stirred and heated to 110° C. to make the Temozolomide dissolved. 150 ml of ethyl acetate was added, stirred for 5 min and cooled down to 10-15° C., crystallized for 4 hours by stirring to give the crystalline form. The resultant crystalline form was filtered, washed with 40 ml of ethyl acetate and dried for 4 hours in vacuum (vacuum degree≦−0.07 Mpa) at 45-50° C. to obtain crystalline Form B3 of Temozolomide (8.0 g). The yield rate was 80%.
Example 14
Preparation of Crystalline Form C of Temozolomide
20 g of Temozolomide was placed into a reaction bottle, into which 150 ml of DMSO was added, the mixture of Temozolomide and DMSO was stirred and heated to 120° C. to make the Temozolomide dissolved. 150 ml of glycol was added, stirred for 15 min and cooled down to 10-15° C., crystallized for 4 hours by stirring to give the crystalline form. The resultant crystalline form was filtered, washed with 50 ml of glycol and dried for 4 hours in vacuum (vacuum degree≦−0.07 Mpa) at 45-50° C. to obtain crystalline Form C of Temozolomide (18 g). The yield rate was 90%.
Example 15
Preparation of Crystalline Form C of Temozolomide
20 g of Temozolomide was placed into a reaction bottle, into which 180 ml of DMSO was added, the mixture of Temozolomide and DMSO was stirred and heated to 100° C. to make the Temozolomide dissolved. 200 ml of glycol was added, stirred for 15 min and cooled down to 10-15° C., crystallized for 4 hours by stirring to give the crystalline form. The resultant crystalline form was filtered, washed with 70 ml of glycol and dried for 4 hours in vacuum (vacuum degree≦−0.07 Mpa) at 45-50° C. to obtain crystalline Form C of Temozolomide (17.6 g). The yield rate was 88%.
Example 16
Preparation of Pharmaceutical Composition as Capsules Containing Crystalline Form A of Temozolomide (represented by Form A0 prepared by using the method of EXAMPLE 1)
1. Formulation:

















Specification:
5
mg



Crystalline Form A of Temozolomide
5
g



Lactose
72
g



Microcrystalline cellulose
15
g



Corn starch
65
g



Sodium carboxymethyl starch
5
g










Polyvinylpyrrolidone (PVP)
proper amount











Magnesium stearate
1
g




1000
capsules










2. Preparation of Capsules:

Crystalline Form A of Temozolomide, lactose, microcrystalline cellulose, corn starch and sodium carboxymethyl starch were loaded into a high-efficient wetting granulator to mix, into which 2% PVP ethanol solution (80%) was added to granulate. Resultant wet granules were dried in a fluidized bed and sized with an 18-mesh sifter, and the obtained dried granules were added with magnesium stearate, properly mixed and loaded into capsules.
Example 17
Preparation of Pharmaceutical Composition as Capsules Containing Crystalline Form B of Temozolomide (represented by Form B0 prepared by using the method of EXAMPLE 6)
1. Formulation:

















Specification:
50
mg



Crystalline Form B of Temozolomide
50
g



Lactose
50
g



Microcrystalline cellulose
10
g



Corn starch
47
g



Sodium carboxymethyl starch
5
g










Polyvinylpyrrolidone (PVP)
proper amount











Magnesium stearate
1
g




1000
capsules










2. Preparation of Capsules:

Crystalline Form B of Temozolomide, lactose, microcrystalline cellulose, corn starch and sodium carboxymethyl starch were loaded into a high-efficient wetting granulator to mix, into which 2% PVP ethanol solution (80%) was added to granulate. Resultant wet granules were dried in a fluidized bed and sized with an 18-mesh sifter, and the obtained dried granules were added with magnesium stearate, properly mixed and loaded into capsules.
Example 18
Preparation of Pharmaceutical Composition as Capsules Containing Crystalline Form C of Temozolomide (represented by Form C prepared by using the method of EXAMPLE 14)
1. Formulation:

















Specification:
50
mg



Crystalline Form C of Temozolomide
50
g



Lactose
50
g



Microcrystalline cellulose
10
g



Corn starch
47
g



Sodium carboxymethyl starch
5
g










Polyvinylpyrrolidone (PVP)
proper amount











Magnesium stearate
1
g




1000
capsules










2. Preparation of Capsules:

Crystalline Form C of Temozolomide, lactose, microcrystalline cellulose, corn starch and sodium carboxymethyl starch were loaded into a high-efficient wetting granulator to mix, into which 2% PVP ethanol solution (80%) was added to granulate. Resultant wet granules were dried in a fluidized bed and sized with an 18-mesh sifter, and the obtained dried granules were added with magnesium stearate, properly mixed and loaded into capsules.

## Claims

1. A method for preparing crystalline forms of Temozolomide, characterized in that, the method consists of the following steps: dissolving Temozolomide in dimethylsulfoxide, into which a second organic solvent is added for recrystallization, whereby the crystalline forms of Temozolomide are prepared, wherein the second organic solvent is methanol, isopropanol, dichloromethane, ethyl acetate or ethylene glycol.

2. The method according to claim 1, wherein the method comprises the following steps: Temozolomide is prepared, into which dimethylsulfoxide with 7-20 times the amount of the Temozolomide (v/w) is added, the mixture of Temozolomide and dimethylsulfoxide is stirred and heated to make the Temozolomide dissolved, then the second organic solvent with 5-30 times the amount of the Temozolomide (v/w) is added, stirred, cooled down, crystallized by stirring, filtered to give the crystalline forms, and the resultant crystalline forms are washed by using the second organic solvent with 2-10 times the amount of the Temozolomide (v/w), and dried in vacuum to give the crystalline forms of Temozolomide.

3. The method according to claim 1, wherein the method comprises the following steps: Temozolomide is prepared, into which dimethylsulfoxide with 7-15 times the amount of the Temozolomide (v/w) is added, the mixture of Temozolomide and dimethylsulfoxide is stirred and heated to 60-140° C. to make the Temozolomide dissolved, then the second organic solvent with 7-20 times the amount of the Temozolomide (v/w) is added, stirred for 5-15min, cooled down to 10-15° C., crystallized for 4 hours by stirring, filtered to give the crystalline forms, and the resultant crystalline forms are washed by using the second organic solvent with 2-5 times the amount of the Temozolomide (v/w), and dried in vacuum to give the crystalline forms of Temozolomide.

4. The method according to claim 1, wherein the second organic solvent is methanol, the obtained crystalline form of Temozolomide has a powder X-ray diffraction spectrum comprising characteristic peaks expressed in terms of 2θ at 10.72±0.2, 14.58±0.2, 17.90±0.2, 26.44±0.2 and 28.68±0.2; it has characteristic absorption peaks at 3423.41, 3388.70, 3112.89, 1755.10, 1728.10, 1674.10, 1452.30, 1265.22 and 948.91 cm−1 in its infrared absorption spectrum; and it has an exothermic peak at 202° C. in its TG-DTA spectrum.

5. The method according to claim 1, wherein the second organic solvent is isopropanol, the obtained crystalline form of Temozolomide has a powder X-ray diffraction spectrum comprising characteristic peaks expressed in terms of 2θ at 7.34±0.2, 14.70±0.2, 22.98±0.2, 23.82±0.2 and 28.10±0.2; it has characteristic absorption peaks at 3388.70, 3114.82, 1758.96, 1681.81, 1452.30, 1265.22, 950.84 and 736.76cm−1 in its infrared absorption spectrum; and it has an exothermic peak at 203° C. in its TG-DTA spectrum.

6. The method according to claim 1, wherein the second organic solvent is dichloromethane; the obtained crystalline form of Temozolomide has a powder X-ray diffraction spectrum comprising characteristic peaks expressed in terms of 2θ at 7.32±0.2, 14.02±0.2, 14.70±0.2, 22.94±0.2 and 23.78±0.2; it has characteristic absorption peaks at 3388.70, 3114.82, 1758.96, 1735.81, 1731.96, 1677.95, 1452.30, 1265.22, 952.77 and 736.76cm−1 in its infrared absorption spectrum; and it has an exothermic peak at 205° C. in its TG-DTA spectrum.

7. The method according to claim 1, wherein the second organic solvent is ethyl acetate; the obtained crystalline form of Temozolomide has a powder X-ray diffraction spectrum comprising characteristic peaks expressed in terms of 2θ at 7.36±0.2, 14.06±0.2, 14.74±0.2, 23.00±0.2 and 23.86±0.2; it has characteristic absorption peaks at 3388.70, 3114.82, 1751.24, 1735.81, 1728.10, 1674.10, 1452.30, 1265.22, 952.77, 730.97 and 711.68cm−1 in its infrared absorption spectrum; and it has an exothermic peak at 200° C. in its TG-DTA spectrum.

8. The method according to claim 1, wherein the second organic solvent is ethylene glycol; the obtained crystalline form of Temozolomide has a powder X-ray diffraction spectrum comprising characteristic peaks expressed in terms of 2θ at 11.46±0.2, 13.20±0.2, 19.64±0.2, 24.58±0.2 and 28.80±0.2; it has characteristic absorption peaks at 3388.70, 3112.89, 1758.96, 1731.96, 1674.10, 1454.23, 1267.14, 950.84, 736.76 and 698.18cm−1 in its infrared absorption spectrum; and it has an exothermic peak at 201° C. in its TG-DTA spectrum.

9. The crystalline form of Temozolomide prepared by the method of claim 8 having a powder X-ray diffraction spectrum with characteristic diffraction peaks as follows:
















Nos.
2θ
d value
Relative intensity I/I0





















1
10.860
8.1400
7



2
11.460
7.7151
100



3
12.140
7.2844
7



4
13.200
6.7018
19



5
14.680
6.0293
17



6
15.420
5.7415
4



7
16.260
5.4468
3



8
16.740
5.2917
2



9
17.120
5.1751
3



10
18.040
4.9132
6



11
19.100
4.6428
4



12
19.640
4.5164
22



13
21.540
4.1221
10



14
23.020
3.8603
14



15
23.900
3.7201
9



16
24.580
3.6187
23



17
25.400
3.5037
4



18
26.520
3.3582
10



19
26.860
3.3165
14



20
27.800
3.2065
6



21
28.800
3.0974
20



22
29.980
2.9781
9



23
30.900
2.8915
15



24
31.140
2.8697
10



25
31.480
2.8395
7



26
32.100
2.7861
7



27
33.600
2.6650
3



28
37.940
2.3696
4



29
38.600
2.3306
5



30
39.620
2.2729
3



31
41.340
2.1822
10



32
43.320
2.0869
4



33
43.580
2.0751
9



34
46.380
1.9561
4



35
46.920
1.9349
15



36
49.780
1.8302
5










it has characteristic absorption peaks at 3388.70, 3112.89, 1758.96, 1731.96, 1674.10, 1454.23, 1267.14, 950.84, 736.76 and 698.18cm−1 in its infrared absorption spectrum, and it has an exothermic peak at 201° C. in its TG-DTA spectrum.