Donald E Randolph

US Patent:

58075674, Sep 15, 1998

Filed:

Dec 11, 1996

Appl. No.:

8/763021

Inventors:

Donald A. Randolph - Wheaton IL
Jodi L. Negri - Wildwood IL
Timothy R. Devine - Whitefish Bay WI
Steven Gitelis - Mallard Oak Brook IL

Assignee:

Wright Medical Technology, Incorporated - Arlington TN

International Classification:

A61F 202
A61K 916
A61K 950

US Classification:

424426

Abstract:

This invention relates to the controlled release of calcium sulfate as well as to the controlled release of an additive to a calcium sulfate matrix such as medicaments or pesticides. The controlled release is achieved by a pellet comprising calcium sulfate. The pellet is prepared by the process comprising mixing powder consisting essentially of alpha-calcium sulfate hemihydrate, a solution comprising water, and, optionally, an additive and a powder consisting essentially of beta-calcium sulfate hemihydrate to form a mixture, and forming said mixture into a pellet, wherein said alpha-calcium sulfate hemihydrate and beta-calcium sulfate hemihydrate powders have specified properties such as BET surface areas, densities, mean particle sizes, and purities. The dissolution rate of the calcium sulfate pellet is controlled by varying the weight ratio of the beta-calcium sulfate hemihydrate powder to the alpha-calcium sulfate hemihydrate powder from 0 to about 3. The invention also provides a method of delivering medicament in vivo by implanting a pellet prepared with medicament into a human or an animal.

US Patent:

6030636, Feb 29, 2000

Filed:

Sep 2, 1998

Appl. No.:

9/145671

Inventors:

Donald A. Randolph - Wheaton IL
Jodi L. Negri - Lakevilla IL
Timothy R. Devine - Whitefish Bay WI
Steven Gitelis - Oak Brook IL

Assignee:

Wright Medical Technology Incorporated - Arlington TN

International Classification:

A61F 202
A61K 916
A61K 950

US Classification:

424426

Abstract:

This invention relates to the controlled release of calcium sulfate as well as to the controlled release of an additive to a calcium sulfate matrix such as medicaments or pesticides. The controlled release is achieved by a pellet comprising calcium sulfate. The pellet is prepared by the process comprising mixing powder consisting essentially of alpha-calcium sulfate hemihydrate, a solution comprising water, and, optionally, an additive and a powder consisting essentially of beta-calcium sulfate hemihydrate to form a mixture, and forming said mixture into a pellet, wherein said alpha-calcium sulfate hemihydrate and beta-calcium sulfate hemihydrate powders have specified properties such as BET surface areas, densities, mean particle sizes, and purities. The dissolution rate of the calcium sulfate pellet is controlled by varying the weight ratio of the beta-calcium sulfate hemihydrate powder to the alpha-calcium sulfate hemihydrate powder from 0 to about 3. The invention also provides a method of delivering medicament in vivo by implanting a pellet prepared with medicament into a human or an animal.

US Patent:

44241976, Jan 3, 1984

Filed:

Sep 29, 1982

Appl. No.:

6/426445

Inventors:

Byron E. Powell - Rollings Meadows IL
Virendar S. Bakhshi - Chicago IL
Donald A. Randolph - Wheaton IL

Assignee:

United States Gypsum Company - Chicago IL

International Classification:

B01J 800
C01B 1700

US Classification:

423244

Abstract:

A process for adsorbing sulfur dioxide from a gas comprising contacting a gas containing SO. sub. 2, such as a flue gas, with about stoichiometric amounts of a specially prepared calcium oxide so that substantially all of the sulfur dioxide content is reacted throughout the calcium oxide particle to form a calcium sulfate reaction product. The useful calcium oxide particles comprise a highly voided skeletal structure of very large surface area and large pore volume with numerous macro pores. Such particles are obtained by flash calcining sand-size grains of calcium carbonate, such as aragonite, calcite or dolomite.

US Patent:

45200734, May 28, 1985

Filed:

Dec 23, 1983

Appl. No.:

6/565197

Inventors:

Donald A. Randolph - Wheaton IL
Kenneth R. Watkins - Wheaton IL

Assignee:

USG Corporation - Chicago IL

International Classification:

B05D 302
B05D 304
B05D 700

US Classification:

428405

Abstract:

Mineral filler materials are provided with improved hydrophobic coatings by pressure coating of porous minerals using steam as a carrier for the coating material. Thereby more complete sealing of fissures and cracks in the porous filler materials' surface is provided, resulting in very water-resistant coated particles useful in filling polymeric substrates such as paints, plastics and joint compounds.

US Patent:

56142064, Mar 25, 1997

Filed:

Mar 7, 1995

Appl. No.:

8/399769

Inventors:

Donald A. Randolph - Wheaton IL
Jodi L. Negri - Lakevilla IL
Timothy R. Devine - Whitefish Bay WI
Steven Gitelis - Oakbrook IL

Assignee:

Wright Medical Technology, Inc. - Arlington TN

International Classification:

A61F 202
A61K 916
A61K 950

US Classification:

424426

Abstract:

This invention relates to the controlled release of calcium sulfate as well as to the controlled release of an additive to a calcium sulfate matrix such as medicaments or pesticides. The controlled release is achieved by a pellet comprising calcium sulfate. The pellet is prepared by the process comprising mixing powder consisting essentially of alpha-calcium sulfate hemihydrate, a solution comprising water, and, optionally, an additive and a powder consisting essentially of beta-calcium sulfate hemihydrate to form a mixture, and forming said mixture into a pellet, wherein said alpha-calcium sulfate hemihydrate and beta-calcium sulfate hemihydrate powders have specified properties such as BET surface areas, densities, mean particle sizes, and purifies. The dissolution rate of the calcium sulfate pellet is controlled by varying the weight ratio of the beta-calcium sulfate hemihydrate powder to the alpha-calcium sulfate hemihydrate powder from 0 to about 3. The invention also provides a method of delivering medicament in vivo by implanting a pellet prepared with medicament into a human or an animal.