Anhydrous mirtazapine and process for preparing the same
AssigneeSumika Fine Chemicals Co., Ltd.
InventorsChiharu Maeda, Sadanobu Yoshikawa, Eiichi Iishi
Life of this patent
Estimating the term…
Abstract
Methods for producing anhydrous mirtazapine crystals that are either (1) substantially free of lower alcohol insolubles or (2) substantially free of residual solvent and have an average particle diameter of from 10 to 50 μm, are provided, and the resulting anhydrous mirtazapine crystals produced thereby, which are useful in pharmaceuticals.
Claims39
An anhydrous mirtazapine crystal substantially free of lower alcohol insolubles.
A process for preparing an anhydrous mirtazapine crystal, comprising:
- filtering a lower alcohol solution of crude mirtazapine to provide a filtrate;
- concentrating the filtrate to provide a concentrated filtrate;
- and
- crystallizing anhydrous mirtazapine from said concentrated filtrate using a precipitation solvent selected from the group consisting of heptane and petroleum ethers.
Anhydrous mirtazapine having an average particle diameter of 10 to 50 μm and substantially free of residual solvent.
A process for preparing anhydrous mirtazapine having an average particle diameter of 10 to 50 μm and substantially free of residual solvent, comprising pulverizing anhydrous mirtazapine crystals to an average particle diameter of 10 to 50 μm.
A process for preparing an anhydrous mirtazapine crystal, comprising:
- a step of filtering a lower alcohol solution of crude mirtazapine to provide a filtrate;
- a step of concentrating the filtrate to provide a concentrated filtrate;
- and
- a step of crystallizing anhydrous mirtazapine from said concentrated filtrate using a precipitation solvent selected from the group consisting of heptane and petroleum ethers.
A process for preparing anhydrous mirtazapine having an average particle diameter of 10 to 50 μm and substantially free of residual solvent, comprising a step of pulverizing anhydrous mirtazapine crystals to an average particle diameter of 10 to 50 μm.
Dependencies are inferred from the claim text.