Claims
- 1. A process for preparing anhydrous mirtazapine crystals comprising:
drying crystals of a mirtazapine hydrate represented by the formula (I): 4wherein n is an integer of 1 to 5, to give anhydrous mirtazapine crystals having a moisture content of not more than 0.6% by weight when the crystals are stored in the air having a relative humidity of 75% at 25° C. under atmospheric pressure for 500 hours.
- 2. The process for preparing anhydrous mirtazapine crystals according to claim 1, wherein the crystals of the mirtazapine hydrate are pulverized, and thereafter the pulverized crystals of the mirtazapine hydrate are dried.
- 3. The process for preparing anhydrous mirtazapine crystals according to claim 2, wherein the crystals of the mirtazapine hydrate are pulverized to an average particle diameter of 10 to 70 μm.
- 4. The process for preparing anhydrous mirtazapine crystals according to claim 2, wherein the pulverized crystals of the mirtazapine hydrate are dried by heating the pulverized crystals at a temperature of 70 to 110° C.
- 5. The process for preparing anhydrous mirtazapine crystals according to claim 1, wherein the mirtazapine hydrate is dried under reduced pressure of 1.33 to 13300 Pa.
- 6. The process for preparing anhydrous mirtazapine crystals according to claim 1, wherein the mirtazapine hydrate is dried and the water content of the resulting anhydrous mirtazapine crystals is not more than 0.5% by weight.
- 7. Anhydrous mirtazapine crystals obtained by the process of claim 1.
- 8. The anhydrous mirtazapine crystals according to claim 7, wherein the crystals have characteristic diffraction peaks in the X-ray diffraction pattern, when angles of diffraction (2θ) are 9.14, 9.38, 14.16, 18.46, 18.56 and 20.56.
- 9. The anhydrous mirtazapine crystals according to claim 7, wherein the crystals have a water content of not more than 0.5% by weight.
Priority Claims (2)
Number |
Date |
Country |
Kind |
11-333049 |
Nov 1999 |
JP |
|
2000-67476 |
Mar 2000 |
JP |
|
Parent Case Info
[0001] This application is a divisional of co-pending application Ser. No. 09/697,329, filed on Oct. 27, 2000 and for which priority is claimed under 35 U.S.C. §120. Application No. 09/697,329 is the continuation-in-part national phase of PCT International Application No. PCT/JP00/04835 filed on Jul. 19, 2000 under 35 U.S.C. §371. This application also claims priority of Application Nos. 11-333049 and 2000-67476, both filed in Japan on Nov. 24, 1999 and Mar. 10, 2000, respectively, under 35 U.S.C. §119. The entire contents of each of the above-identified applications are hereby incorporated by reference.
Divisions (1)
|
Number |
Date |
Country |
Parent |
09697329 |
Oct 2000 |
US |
Child |
10041495 |
Jan 2002 |
US |
Continuation in Parts (1)
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Number |
Date |
Country |
Parent |
PCT/JP00/04835 |
Jul 2000 |
US |
Child |
09697329 |
Oct 2000 |
US |