Chitosan materials from carbonic acid solution

Inventors

McCarthy, Simon • McGrath, Barbara • KUHN, Sam • Kimball, Jess • Stolten, Michael • Bennett, Amanda

Assignees

Tricol Biomedical Inc

Abstract

The present invention comprises chitosan materials and methods of using carbonic acid for aqueous solubilization of neutralized or pre-treated chitosan gels and provides, among other things, substantially acid salt free composition native final forms without requiring subsequent acid salt elution. The invention includes chitosan-based solid and semi-solid material forms, optionally reinforced with chitosan fibers, such as powders, fibers, films, matrices, sponges, implants, scaffolds, fillers, and hydrogels. Native final forms are produced from chitosan powder solubilized in an aqueous acidic solution, processed to form a high pH hydrated chitosan gel precipitate material that is then neutralized by water washing and re-solubilized substantially to chitosan solution using carbonic acid. Chitosan materials can be mixed in solution with one or more of other hydrophilic polymers to create compositional heterogeneity and pharmaceutical agents to achieve controlled release of the agent(s) from the final forms at the site of application.

Core Innovation

The invention provides native final form chitosan compositions produced by using carbonic acid to solubilize a substantially neutralized chitosan gel. Carbonic acid forms an aqueous chitosan carbonic acid solution, and the resulting solution is subjected to irreversible phase separation caused via mechanical action including at least one of shear and freezing.

The invention targets native solid or semi-solid final forms that are substantially acid salt free. The formation uses mechanical action such as shear and/or freezing to induce irreversible phase separation in the aqueous chitosan carbonic acid solution, yielding native final forms that are substantially acid-salt-free without acid-salt elution and with resistance to dissolution when re-exposed to the original solvent.

The disclosed compositions include powders, fibers, films, matrices, sponges, implants, scaffolds, fillers, and hydrogels. Hydrophilic polymers can be included for compositional heterogeneity, and pharmaceutical active agents can be included for controlled release.

Claims Coverage

The document contains three independent method claims. The claims share a common inventive sequence: carbonic acid solubilization of a substantially neutralized chitosan gel to form an aqueous chitosan carbonic acid solution, followed by irreversible phase separation via mechanical action including at least one of shear and freezing.

Across the independent claims, the core coverage is production of chitosan compositions by carbonic acid solubilization of a substantially neutralized chitosan gel and irreversible phase separation via mechanical action including shear and/or freezing, yielding native final forms, non-adhesive compositions, and substantially acid salt free solid or semi-solid compositions.

Stated Advantages

Documented Applications