Patents by Inventor Akiyo Ohtsuka

Akiyo Ohtsuka has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Polymorphs of donepezil hydrochloride and process for production
    Patent number: 6140321
    Abstract: Donepezil hydrochloride, 1-benzyl-4-[(5,6-dimethoxy-1-indanon)-2-yl]methylpiperidine hydrochloride, is provided here in the form of four polymorphs which are stable against heat and humidity in the pharmaceutical use. They can be industrially produced. They are specified by peaks in X-ray powder diffraction pattern and absorption peaks in infrared absorption spectra in potassium bromide.
    Type: Grant
    Filed: December 30, 1996
    Date of Patent: October 31, 2000
    Assignee: Eisai Co., Ltd.
    Inventors: Akio Imai, Hideaki Watanabe, Takashi Kajima, Yasushi Ishihama, Akiyo Ohtsuka, Tomohide Tanaka
  • Polymorphs of donepezil hydrochloride and process for production
    Patent number: 5985864
    Abstract: Donepezil hydrochloride, 1-benzyl-4-[(5,6-dimethoxy-1-indanon)-2-yl]methylpiperidine hydrochloride, is provided here in the form of four polymorphs which are stable against heat and humidity in the pharmaceutical use. They can be industrially produced. They are specified by peaks in X-ray powder diffraction pattern and absorption peaks in infrared absorption spectra in potassium bromide.
    Type: Grant
    Filed: June 6, 1997
    Date of Patent: November 16, 1999
    Assignee: Eisai Co., Ltd.
    Inventors: Akio Imai, Hideaki Watanabe, Takashi Kajima, Yasushi Ishihama, Akiyo Ohtsuka, Tomohide Tanaka, Yukio Narabu