Patents by Inventor Nam S. Choi

Nam S. Choi 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).

  • Pharmaceutical comprising drug and polymer
    Patent number: 4282201
    Abstract: This invention concerns polymers of the general formula: ##STR1## wherein R is a multivalent hydrocarbon radical and Het is a 5 to 8 membered heterocyclic system having a nitrogen, oxygen or sulfur hetero atom. The polymers are useful for making articles of manufacture and as coating for delivering beneficial agents.
    Type: Grant
    Filed: November 5, 1979
    Date of Patent: August 4, 1981
    Assignee: ALZA Corporation
    Inventor: Nam S. Choi
  • Composition comprising useful agent such as fertilizers, housed in heterocyclic polymer
    Patent number: 4259102
    Abstract: This invention concerns polymers of the general formula: ##STR1## wherein R is a multivalent hydrocarbon radical and Het is a 5 to 8 membered heterocyclic system having a nitrogen, oxygen or sulfur hetero atom. The polymers are useful for making articles of manufacture and as coating for delivering beneficial agents such as fertilizers.
    Type: Grant
    Filed: November 5, 1979
    Date of Patent: March 31, 1981
    Assignee: ALZA Corporation
    Inventor: Nam S. Choi
  • Polymers comprising heterocyclic system
    Patent number: 4246397
    Abstract: This invention concerns polymers of the general formula: ##STR1## wherein R is a multivalent hydrocarbon radical and Het is a 5 to 8 membered heterocyclic system having a nitrogen, oxygen or sulfur hetero atom. The polymers are useful for making articles of manufacture and as coating for delivering beneficial agents.
    Type: Grant
    Filed: February 2, 1979
    Date of Patent: January 20, 1981
    Assignee: Alza Corporation
    Inventor: Nam S. Choi
  • Novel orthoester polymers and orthocarbonate polymers
    Patent number: 4180646
    Abstract: The invention concerns orthoester and orthocarbonate polymers having a repeating mer comprising a hydrocarbon radical and a symmetrical dioxycarbon unit of the general formula: ##STR1## wherein R.sub.1 is a multivalent hydrocarbon radical, R.sub.2 and R.sub.3 are hydrocarbon radicals with at least one of R.sub.2 or R.sub.3 bonded to the dioxycarbon through an oxygen linkage, and which polymers are synthesized by reacting a polyol with an orthoester or orthocarbonate. The polymers are useful for making articles of manufacture, including devices and coatings for delivering beneficial agents.
    Type: Grant
    Filed: March 3, 1978
    Date of Patent: December 25, 1979
    Assignee: Alza Corporation
    Inventors: Nam S. Choi, Jorge Heller
  • Erodible agent releasing device comprising poly(orthoesters) and poly(orthocarbonates)
    Patent number: 4138344
    Abstract: The invention concerns orthoester and orthocarbonate polymers having a repeating mer comprising a hydrocarbon radical and a symmetrical dioxycarbon unit of the general formula: ##STR1## WHEREIN R.sub.1 is a multivalent hydrocarbon radical, R.sub.2 and R.sub.3 are hydrocarbon radicals with at least one of R.sub.2 or R.sub.3 bonded to the dioxycarbon through an oxygen linkage, and which polymers are synthesized by reacting a polyol with an orthoester or orthocarbonate. The polymers are useful for making articles of manufacture, including devices and coatings for delivering beneficial agents.
    Type: Grant
    Filed: August 24, 1977
    Date of Patent: February 6, 1979
    Assignee: ALZA Corporation
    Inventors: Nam S. Choi, Jorge Heller
  • Structured orthoester and orthocarbonate drug delivery devices
    Patent number: 4131648
    Abstract: The invention concerns orthoester and orthocarbonate polymers having a repeating mer comprising a hydrocarbon radical and a symmetrical dioxycarbon unit of the general formula: ##STR1## WHEREIN R.sub.1 is a multivalent hydrocarbon radical, R.sub.2 and R.sub.3 are hydrocarbon radicals with at least one of R.sub.2 or R.sub.3 bonded to the dioxycarbon through an oxygen linkage, and which polymers are synthesized by reacting a polyol with an orthoester or orthocarbonate. The polymers are useful for making articles of manufacture, including devices and coatings for delivering beneficial agents.
    Type: Grant
    Filed: March 2, 1978
    Date of Patent: December 26, 1978
    Assignee: Alza Corporation
    Inventors: Nam S. Choi, Jorge Heller