Patents by Inventor Younsik Cha

Younsik Cha 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: 5874075
    Abstract: The invention relates to stable compositions of proteins and related methods wherein a protein capable of transitioning into the molten globular state is contacted with a negatively charged lipid vesicle, thereby stabilizing the protein against thermally-induced aggregation, denaturation, and loss of activity. The protein:phospholipid complex directly stabilizes the secondary and tertiary structure of the protein, and the compositions are useful in high temperature formulations and in novel delivery vehicles.
    Type: Grant
    Filed: March 31, 1995
    Date of Patent: February 23, 1999
    Assignee: Amgen Inc.
    Inventors: David Collins, Younsik Cha, David Brems
  • Patent number: 5702717
    Abstract: A system and method for the parenteral delivery of a drug in a biodegradable polymeric matrix to a warm blooded animal as a liquid with the resultant formation of a gel depot for the controlled release of the drug. The system comprises an injectable biodegradable block copolymeric drug delivery liquid having reverse thermal gelation properties. The delivery liquid is an aqueous solution having dissolved or dispersed therein an effective amount of a drug intimately contained in a biodegradable block copolymer matrix. The copolymer has a reverse gelation temperature below the body temperature of the animal to which it is administered and is made up of (i) a hydrophobic A polymer block comprising a member selected from the group consisting of poly(.alpha.-hydroxy acids) and poly(ethylene carbonates) and (ii) a hydrophilic B polymer block comprising a polyethylene glycol. Prior to use the liquid is maintained at a temperature below the reverse gelation temperature of the block copolymer.
    Type: Grant
    Filed: October 25, 1995
    Date of Patent: December 30, 1997
    Assignee: Macromed, Inc.
    Inventors: Younsik Cha, Young Kweon Choi, You Han Bae
  • Patent number: 5665428
    Abstract: Peptide/protein biodegradable drug delivery devices are prepared as microspheres without the use of solvents by a polymer melt process. A melt of thermostable polypeptides and an appropriate low melting block copolymer mixture is prepared and dispersed in an appropriate fluid medium such as air, water or an immiscible organic fluid without using any organic solvent to form microdroplets. The fluid medium is cooled to solidify the microdroplets into microspheres and then collected and purified or further processed as drug delivery devices. These biodegradable microspheres are suitable as implantable or injectable pharmaceutical formulations. Following administration as solid microspheres into the body of a warm blooded animal, the formulations absorb water from the body to form a hydrogel from which the polypeptide is released continuously over an extended period of time.
    Type: Grant
    Filed: October 25, 1995
    Date of Patent: September 9, 1997
    Assignee: Macromed, Inc.
    Inventors: Younsik Cha, Young Kweon Choi, Chaul Min Pai