Multi-encapsulated formulations made with oxidized cellulose
A microsphere and method for forming the same are disclosed. The microsphere includes modified cellulose and at least one of a visualization agent, a magnetic material, or a radioactive material.
1. A method for forming a plurality of microspheres comprising:
forming an oxidized cellulose solution by contacting an oxidized cellulose with a solvent under an inert atmosphere to form a swelled oxidized cellulose mixture;
adjusting the swelled oxidized cellulose mixture to a first temperature;
contacting the swelled oxidized cellulose mixture with a salt under the inert atmosphere to form an oxidized cellulose solution;
adjusting the oxidized cellulose solution to a second temperature;
contacting the oxidized cellulose solution with at least one radioactive material 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 the plurality of microspheres.
2. The method according to claim 1 , wherein the third phase liquid is miscible with the continuous composition and the discontinuous composition.
3. The method according to claim 2 , wherein the third phase liquid is selected from the group consisting of isopropyl myristate, hexane, triglycerides and combinations thereof.
4. The method according to claim 1 , wherein the third phase liquid is present in an amount from about 300% by volume to about 200% by volume of the continuous phase liquid.
5. The method according to claim 1 , 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.
6. The method according to claim 1 , wherein the solvent is selected from the group consisting of N,N-Dimethylacetamide, N-methyl-2-pyrrolidinone, and combinations thereof.
7. The method according to claim 1 , wherein the salt is selected from the group consisting of lithium halides, sodium halides, potassium halides, and combinations thereof.
8. The method according to claim 1 , wherein the plurality of microspheres include oxidized cellulose having a degree of oxidation from about 80% to about 120% of a degree of oxidation of the oxidized cellulose prior to dissolution.
9. The method according to claim 1 , wherein the plurality of microspheres include oxidized cellulose having a molecular weight from about 80% to about 120% of the molecular weight of the oxidized cellulose prior to dissolution.
10. The method according to claim 1 , further comprising encapsulating one or more of the plurality of microspheres within a shell.