Manufacturing process for polysaccharide beads
The invention discloses a method of manufacturing polysaccharide beads, comprising the steps of: i) providing a water phase comprising an aqueous solution of a polysaccharide; ii) providing an oil phase comprising at least one water-immiscible organic solvent and at least one oil-soluble emulsifier; iii) emulsifying the water phase in the oil phase to form a water-in-oil (w/o) emulsion; and iv) inducing solidification of the water phase in the w/o emulsion, wherein the organic solvent is an aliphatic or alicyclic ketone or ether.
1. A crosslinked polysaccharide bead, comprising 0.1-100 ppm of a C 6 -C 10 aliphatic or alicyclic ketone or ether.
2. The crosslinked polysaccharide bead of claim 1 , wherein said C 6 -C 10 aliphatic or alicyclic ketone or ether is defined by Formula I, II or III, such as by Formula II,
wherein:
R 1 and R 2 are, independently of each other, C 1 -C 5 alkyl groups;
R 3 is a C 1 -C 5 alkylene group;
R 4 is hydrogen or a C 1 -C 5 alkyl group; and
R 5 and R 6 are, independently of each other, C 1 -C 6 alkyl or cycloalkyl groups.
3. The crosslinked polysaccharide bead of claim 1 , wherein said C 6 -C 10 aliphatic or alicyclic ketone or ether is selected from the group consisting of 2-methylcyclohexanone, 3-methylcyclohexanone, 4-methylcyclohexanone, cyclohexanone, diisobutylketone, methyl n-amylketone, methyl isoamyl ketone, methyl isobutyl ketone, cyclopentyl methyl ether and their mixtures.
4. The crosslinked polysaccharide bead of claim 1 , having a diameter of 40-125 μm in dry form.
5. The crosslinked polysaccharide bead of claim 1 , comprising at least 0.1 mmol/g covalently bonded charged groups.
6. The crosslinked polysaccharide bead of claim 5 , comprising 1-6 mmol/g covalently bonded charged groups.
7. The crosslinked polysaccharide bead of claim 5 , wherein the covalently bonded charged groups comprise carboxymethyl-, sulfopropyl-, diethyl aminoethyl-, and/or diethyl-(2-hydroxy-propyl)aminoethyl-groups.