Patents by Inventor Charles L. Hughes

Charles L. Hughes 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: 5549830
    Abstract: A method of processing a feed liquid in the form of an extraction solution containing taxane solutes that is an extraction product of a biomass utilizes at least one semipermeable membrane to remove at least one taxane solute from the solvent by reverse osmosis. The feed liquid is placed in a first region on one side of the membrane and pressure is supplied to transport constitutes of the feed liquid across the membrane to a second region as a first permeate while retaining a first retentate in the first region. The taxane solute may be either retained or transported. Where the taxane solute is transported, the method can further include the use of a second semipermeable membrane of a pore size different from the first membrane and supplying a pressure to transport some of the first permeate across the second membrane as a second permeate while retaining a majority of the desired taxane solute as a second retentate.
    Type: Grant
    Filed: February 28, 1994
    Date of Patent: August 27, 1996
    Assignee: NaPro BioTherapeutics, Inc.
    Inventors: David R. Carver, Timothy R. Prout, Christopher T. Workman, Charles L. Hughes
  • Patent number: 5281727
    Abstract: The present invention is a method that uses an absorption column for the cleavage and recovery of taxanes, which are not normally detected as free taxanes. The method processes a first solution that contains standard detectable taxanes and other undetectable taxane compounds to generate a second solution that contains a higher percentage of detectable standard taxane then the first solution. The first step of this method is loading a column having a first opening and a second opening with an ion exchange media. The next step is placing the first solution in the first opening of the column so that the first solution passes through the ion exchange media in the column and flows to the second opening. Thus, the taxane compounds are converted to standard taxanes by an ion exchange reaction and the second solution is formed.
    Type: Grant
    Filed: November 27, 1992
    Date of Patent: January 25, 1994
    Assignee: NaPro BioTherapeutics, Inc.
    Inventors: David R. Carver, Timothy R. Prout, Christopher T. Workman, Donia L. Henderson, Charles L. Hughes