Patents by Inventor Sadao Hirota

Sadao Hirota 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).

  • Patent number: 6060080
    Abstract: A liposomal aqueous dispersion and method of making the liposomal aqueous dispersion is useful for encapsulation of drugs. The liposomal aqueous dispersion comprises: an aqueous suspension medium; multilamellar liposomes comprising an anionic phospholipid and cholesterol as essential components; neutral phospholipid in a mole ratio of 0 to 40% based on the total amount of said multilamellar liposomes; and a cation moiety-containing water-soluble drug, wherein the electrolyte concentration of said aqueous suspension medium is not more than 40 mM.
    Type: Grant
    Filed: March 23, 1995
    Date of Patent: May 9, 2000
    Assignee: Daiichi Pharmaceutical Co., Ltd.
    Inventors: Hiroshi Kikuchi, Kiyoto Yachi, Sadao Hirota
  • Patent number: 5376380
    Abstract: A method of producing liposomal products which comprises treating a positively or negatively charged, freeze- or spray-dried liposomal preparation with an aqueous solution of a drug charged oppositely to the charge of the liposomes.
    Type: Grant
    Filed: June 22, 1993
    Date of Patent: December 27, 1994
    Assignee: Daiichi Pharmaceutical Co., Ltd.
    Inventors: Hiroshi Kikuchi, Kiyoto Yachi, Hiromi Morita, Sadao Hirota
  • Patent number: 5141751
    Abstract: Lipid membrane structures containing, in the lipid membrane thereof, a compound represented by formula (I): ##STR1## wherein R.sub.1 represents a hydrogen atom or a fatty acid residue; R.sub.2 represents a hydrogen atom or an acyclic hydrocarbon residue; R.sub.3 represents an amino group, a guanidino group or an amidino group; and n represents an integer of from 1 to 6; provided that R.sub.1 and R.sub.2 do not represent hydrogen atoms at the same time, or a salt thereof. The lipid membrane structures exhibit excellent specific affinity for tumor cells and can be delivered preferentially to tumor cells.
    Type: Grant
    Filed: March 4, 1991
    Date of Patent: August 25, 1992
    Assignee: Daiichi Pharmaceutical Co., Ltd.
    Inventors: Munehiro Tomikawa, Sadao Hirota, Hitoshi Yamauchi, Hiroshi Kikuchi, Yasuyoshi Kawato
  • Patent number: 5096891
    Abstract: An ointment comprising an adenosine 3',5'-cyclic phosphate derivative as an active ingrediment, an ointment base having water-absorbing and drying properties, a saccharide and/or inorganic high polymer is disclosed. The ointment exhibits improved stability of the adenosine 3',5'-cyclic phosphate derivative.
    Type: Grant
    Filed: March 30, 1989
    Date of Patent: March 17, 1992
    Assignee: Daiichi Seiyaku Co., Ltd.
    Inventors: Sadao Hirota, Hitoshi Yamauchi
  • Patent number: 4983725
    Abstract: Novel mannobiose derivative represented by the general formula [I]: ##STR1## wherein groups of R.sub.1 to R.sub.5 each represents --OH, --OR.sub.6, --NHR.sub.6, (R.sub.6 represents an acyl group) or a group represented by the following formula (a), (b), (c), (d) or (e), provided that one of R.sub.1 to R.sub.5 represents --OR.sub.6 or --NHR.sub.6, one of the other 4 groups of R.sub.1 to R.sub.5 represents one of the groups represented by the formulae (a) to (e), and the remaining 3 groups of R.sub.1 to R.sub.5 represent --OH: ##STR2## wherein represents .alpha. or .beta. bond are provided by the invention.These compounds give liposomes a specific affinity for Kupffer cells of liver, and can be produced industrially.
    Type: Grant
    Filed: March 31, 1988
    Date of Patent: January 8, 1991
    Assignees: Meito Sangyo Co., Ltd., Daiichi Seiyaku Co., Ltd.
    Inventors: Hideki Miyaji, Shusaburo Hokukoku, Munehiro Tomikawa, Sadao Hirota, Hiroshi Kikuchi
  • Patent number: 4960595
    Abstract: Lipid membrane structures containing a lactose monofatty acid ester or amide are disclosed. The lipid membrane structures are delivered preferentially to the liver parenchymal cells and are useful as carriers of drugs.
    Type: Grant
    Filed: November 16, 1987
    Date of Patent: October 2, 1990
    Assignee: Daiichi Seiyaku Co., Ltd.
    Inventors: Sadao Hirota, Hiroshi Kikuchi, Hitoshi Yamauchi, Munehiro Tomikawa
  • Patent number: 4923862
    Abstract: A topical preparation containing, as an active ingredient, 9-fluoro-3-methyl-10-(4-methyl-1-piperazinyl)-7-oxo-2,3-dihydro-7H-pyrido[ 1,2,3][1,4]-benzoxazine-6-carboxylic acid or a salt thereof.
    Type: Grant
    Filed: December 17, 1987
    Date of Patent: May 8, 1990
    Assignee: Daiichi Seiyaku Co., Ltd.
    Inventor: Sadao Hirota