Patent ID: 8785622

Claim:
A method for producing crosslinked derivatized polysaccharides, comprising: (a) contacting particles of a polysaccharide with a titanium compound in an aqueous medium having an alkaline pH under conditions appropriate to intra-particulately crosslink the particles; (b) reacting, prior to or after the step of contacting the particles of polysaccharide with the titanium compound, the particles of polysaccharide with a derivatizing agent under conditions appropriate to produce derivatized polysaccharide particles; (c) washing the titanium crosslinked and derivatized particles; (d) contacting, concurrently with or after the step of washing the titanium crosslinked and derivatized particles, such particles with an aqueous medium having an acidic pH under conditions appropriate to substantially de-crosslink the particles; and (e) contacting, concurrently with or after step (d), the de-crosslinked particles with a glyoxal compound under conditions appropriate to intra-particulately crosslink the particles.