Cellulose matrix encapsulation and method
AssigneesUniversity of Alabama, PG Research Foundation
InventorsJohn David Holbrey, Scott K. Spear, Megan B. Turner, Richard Patrick Swatloski, Robin Don Rogers
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Abstract
A regenerated cellulose-encapsulated active substance and a method for encapsulating an active substance in a regenerated cellulose matrix are disclosed. The distribution of the active substance is preferably substantially homogeneous within the matrix of regenerated cellulose. The regenerated cellulose (i) has about the same molecular weight as the original cellulose from which it is prepared (ii) is substantially free of added substituent groups relative to the starting cellulose and is also substantially free of entrapped ionic liquid degradation products.
Claims27
A method for forming a regenerated cellulose-encapsulated active substance that comprises the steps of:
- (a) providing a composition of cellulose dissolved in a molten hydrophilic ionic liquid solvent along with an active substance dissolved or dispersed substantially homogeneously therein, said solution being substantially free of water, organic solvent or nitrogen-containing base, wherein said ionic liquid is comprised of cations and anions;
- (b) admixing said solution with a liquid non-solvent for said cellulose that is miscible with said ionic liquid, said active substance being substantially insoluble in said non-solvent, said admixing forming a regenerated cellulose solid phase and an ionic liquid phase, whereby said active substance is encapsulated and substantially homogeneously dispersed in the formed regenerated cellulose solid phase, and wherein said regenerated cellulose has substantially the same molecular weight as the cellulose of step (a) and is substantially free of ionic liquid degradation products.
A method for forming a regenerated cellulose-encapsulated active substance that comprises the steps of:
- (a) providing a composition of cellulose dissolved in a molten hydrophilic ionic liquid solvent that is molten at a temperature of less than about 150° C. along with an active substance dissolved or dispersed substantially homogeneously therein, said solution being substantially free of water, organic solvent, or nitrogen-containing base, wherein said ionic liquid is comprised of cations and anions, wherein the cations correspond in structure to a formula selected from the group consisting of
- wherein R1 and R2 are independently a C1-C6 alkyl group or a C1-C6 alkoxyalkyl group, and R3, R4, R5, R6, R7, R8 and R9 (R3-R9), when present, are independently a hydrido, a C1-C6 alkyl, a C1-C6 alkoxyalkyl group or a C1-C6 alkoxy group, and the anions of the ionic liquid are halogen, pseudohalogen, or C1-C6 carboxylate and the anions of said ionic liquid are halogen or pseudohalogen;
- and
- (b) admixing said solution with a liquid non-solvent for said cellulose that is miscible with said ionic liquid, said active substance being substantially insoluble in said non-solvent, said admixing forming a regenerated cellulose solid phase and an ionic liquid phase, whereby said active substance is encapsulated and substantially homogeneously dispersed in the formed regenerated cellulose solid phase, and wherein said regenerated cellulose has substantially the same molecular weight as the cellulose of step (a) and is substantially free of ionic liquid degradation products;
- and
- (c) collecting the formed regenerated cellulose solid phase.
A regenerated cellulose-encapsulated active substance that comprises an active substance substantially homogeneously distributed within a matrix of regenerated cellulose, wherein said regenerated cellulose (i) has about the same molecular weight as the original cellulose from which it is prepared, (ii) is substantially free of an increased amount of substituent groups relative to the starting cellulose, and is (iii) substantially free of entrapped ionic liquid degradation products.
A regenerated cellulose-encapsulated active substance that comprises a hydrophobic ionic liquid-coated active substance substantially homogeneously distributed within a matrix of regenerated cellulose, wherein said regenerated cellulose (i) has about the same molecular weight as the original cellulose from which it is prepared, (ii) is substantially free of an increased amount of substituent groups relative to the starting cellulose, and is (iii) substantially free of entrapped ionic liquid degradation products.
Dependencies are inferred from the claim text.