Oxidized cellulose microspheres

Patent metadata

Field	Value
Publication number	US-9687450-B2
Application number	US-201615054479-A
Country	US
Kind code	B2
Filing date	Feb 26, 2016
Priority date	May 31, 2012
Publication date	Jun 27, 2017
Grant date	Jun 27, 2017

Abstract

A process for forming microspheres is disclosed. The process includes contacting a solvent with a modified cellulose to form a solution; contacting the modified cellulose solution with at least one bioactive agent to form a discontinuous phase liquid; contacting the discontinuous phase liquid with a continuous phase liquid to form an emulsion; and contacting the emulsion with a third phase liquid to extract the solvent from the emulsion, thereby forming a plurality of modified cellulose microspheres.

First claim

What is claimed is:

1. A microsphere comprising:
an oxidized cellulose; and
at least one bioactive agent.

2. The microsphere according to claim 1 , wherein the bioactive agent is selected from the group consisting of a hydrophilic bioactive agent, a protein bioactive agent, and combinations thereof.

3. The microsphere according to claim 1 , wherein the microsphere is formed by:
contacting an oxidized cellulose solution comprising a solvent with the at least one bioactive agent to form a discontinuous phase liquid;
contacting the discontinuous phase liquid with a continuous phase liquid to form an emulsion; and
contacting the emulsion with a third phase liquid to extract the solvent from the emulsion thereby forming a plurality of microspheres.

4. The microsphere according to claim 3 , wherein the third phase liquid is miscible with the continuous phase liquid and the discontinuous phase liquid.

5. The microsphere according to claim 3 , wherein the third phase liquid is selected from the group consisting of isopropyl myristate, hexane, triglycerides and combinations thereof.

6. The microsphere according to claim 3 , wherein the third phase liquid is present in an amount from about 130% by volume to about 170% by volume of the continuous phase liquid.

7. The microsphere according to claim 3 , further comprising forming the oxidized cellulose solution by:
contacting an oxidized cellulose with the solvent under an inert atmosphere to form a swelled oxidized cellulose;
adjusting the swelled oxidized cellulose mixture to a first temperature;
contacting the swelled oxidized cellulose after adjusting the first temperature with a salt under the inert atmosphere to form an oxidized cellulose solution; and
adjusting the oxidized cellulose solution to a second temperature.

8. The microsphere according to claim 7 , wherein the first temperature is from about 115° C. to about 145° C. and the second temperature is from about 90° C. to about 120° C.

9. The microsphere according to claim 7 , wherein the solvent is selected from the group consisting of N,N-Dimethylacetamide, N-methyl-2-pyrrolidinone, and combinations thereof.

10. The microsphere according to claim 7 , wherein the salt is selected from the group consisting of lithium halides, sodium halides, potassium halides, and combinations thereof.

11. The microsphere according to claim 3 , wherein the continuous phase liquid is selected from the group consisting of plant-based oils, petroleum-based oils, silicone-based oils, and combinations thereof.

12. The microsphere according to claim 3 , wherein the third phase liquid is miscible with the continuous phase liquid and immiscible with the discontinuous phase liquid.

13. The microsphere according to claim 3 , wherein the third phase liquid is present in an amount from about 8.33% by volume to about 11.11% by volume of the continuous phase liquid.

14. The microsphere according to claim 1 , wherein the at least one bioactive agent is hydrophobic.

Assignees

• Covidien Lp

Inventors

• Blaskovich Phillip
• Tramontano Valentino
• Kennedy Joshua
• Ohri Rachit

Classifications

• A61K9/1682 Primary

  Processes · CPC title

• A61K31/714

  Cobalamins, e.g. cyanocobalamin, i.e. vitamin B12 · CPC title

• A61L27/20

  Polysaccharides · CPC title

• A61K9/1652 Primary

  Polysaccharides, e.g. alginate, cellulose derivatives; Cyclodextrin (homeopathic globules A61K9/1623) · CPC title

• A61L15/28

  Polysaccharides or their derivatives {(A61L15/225 takes precedence)} · CPC title