Novel Method for Producing Doxazosin Mesylate in a Crystalline Modification Designated as Form A

摘要

The present invention relates to a process for the preparation of doxazosin mesylate in modification A. The method characterized by the doxazosin in a mixture of an aprotic polar organic solvent and dissolved in methanol with methanesulfonic acid. To remove any turbidity of water in the obtained solution as desired. The clear solution was thus prepared are seeded with Form A crystals doxazosin mesylate, and separating the resulting product after the heating and cooling. It is then washed with the product with an organic solvent and dried.