Chitosan Hydrochloride

CAS No:	70694-72-3
EINECS No:	615-145-0
Synonyms:	Chitosan HCl, deacetylated chitin hydrochloride, poliglusam hydrochloride, water-soluble chitosan

Product Summary

Chitosan hydrochloride is the water-soluble, protonated salt of chitosan, a biodegradable, biocompatible cationic linear polysaccharide. It carries abundant –NH₃⁺ groups in aqueous media, enabling strong electrostatic interactions with anionic biomolecules and cell surfaces. These properties underpin its wide use as a mucoadhesive excipient, antimicrobial/hemostatic agent, and polycation for gene/drug delivery and colloid/flocculation applications.

As a polymeric material, the exact formula of chitosan hydrochloride varies with degree of polymerization and deacetylation.

Function

Chitosan hydrochloride is valued for its biocompatibility, biodegradability, and cationic nature. Its water solubility improves the bioavailability of chitosan and promotes gel formation, enabling the creation of physical barriers such as anti-adhesion coatings or protective skincare films. The positively charged polymer readily binds to negatively charged cells and pathogens, allowing efficient electrostatic complexation with drugs or nucleic acids such as DNA.

Mechanism of Action

Chelation: The amino and hydroxyl groups on the chitosan backbone can chelate metal ions such as Fe²⁺, Zn²⁺, Cu²⁺, and Mg²⁺. These trace metals are often co-factors for key microbial enzymes and are required for metabolic processes, biofilm development, and toxin production. By sequestering these ions, chitosan hydrochloride effectively starves microorganisms of essential nutrients, impairing growth and virulence. Chelation also contributes to antioxidant and preservative effects in some formulations.
Tight-junction modulation & bioadhesion: On mucosal surfaces, the protonated chitosan hydrochloride chains form strong ionic and hydrogen-bond interactions with negatively charged mucins and glycoproteins, creating a mucoadhesive layer. This close contact increases the residence time of the formulation, improving local drug concentration. Additionally, chitosan hydrochloride can transiently open tight junctions between epithelial cells by interacting with membrane proteins and the cytoskeleton, enhancing paracellular permeability (basis for many drug-delivery uses).
Electrostatic interactions: Protonated –NH₃⁺ groups of chitosan hydrochloride bind to negatively charged bacterial/fungal cell envelopes - such as teichoic acids in Gram-positive bacteria or lipopolysaccharides in Gram-negative bacteria. This interaction disrupts the integrity of the cell wall and outer membrane, leading to increased permeability. The compromised barrier allows leakage of essential intracellular components (e.g., potassium ions, nucleotides, proteins), ultimately causing cell death. The strength of this effect is influenced by pH (greater protonation in acidic conditions), degree of deacetylation (more free amino groups = stronger charge density), and molecular weight (affecting chain length and binding coverage).

Applications in Scientific Research

Chitosan hydrochloride, a water-soluble derivative of chitosan, has emerged as a versatile biomaterial in scientific research due to its enhanced solubility, biocompatibility, and functional versatility. Its key research applications are below:

Drug delivery & biomedical: Mucoadhesive solutions/gels/films; nanoparticles and polyelectrolyte complexes for oral, nasal, ocular, and transdermal delivery; permeation enhancer in epithelial models.
Gene delivery: Nonviral polyplex formation with DNA/RNA (CMC-tunable transfection reagent research).
Antimicrobial coatings & wound care: Incorporation into dressings/films for bacteriostatic surfaces and hemostasis.
Tissue engineering: Blends and crosslinked scaffolds (e.g., with collagen/gelatin) owing to biocompatibility and positive charge.
Colloid science & purification: Flocculant for water treatment and bioseparations; surface functionalization of nanoparticles (including Au/Ag) via amines.

Packaging & Storage

Sources: Obtained by deacetylation of chitin to chitosan, followed by protonation/neutralization with HCl to form the water-soluble chloride salt.
Storage: at room temperature, protect from moisture

References

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Sugamori T, et al. 2000: Local hemostatic effects of microcrystalline partially deacetylated chitin hydrochloride, J Biomed Mater Res. 49(2):225-32.
Kim TH, et al. 2004: Galactosylated chitosan/DNA nanoparticles prepared using water-soluble chitosan as a gene carrier, Biomaterials. 25(17):3783-92.
Jeong YI, et al. 2017: Simple nanophotosensitizer fabrication using water-soluble chitosan for photodynamic therapy in gastrointestinal cancer cells, Int J Pharm. 532(1):194-203.
Hu Y, et al. 2009: Self-aggregation of water-soluble chitosan and solubilization of thymol as an antimicrobial agent, J Biomed Mater Res A. 90(3):874-81.
Zhang Y, et al. 2014: Fabrication, characterization and antimicrobial activities of thymol-loaded zein nanoparticles stabilized by sodium caseinate-chitosan hydrochloride double layers, Food Chem. 142:269-75.
Kim MS, et al. 2002: Water-soluble chitosan inhibits the production of pro-inflammatory cytokine in human astrocytoma cells activated by amyloid beta peptide and interleukin-1beta, Neurosci Lett. 321(1-2):105-9.
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Wang B, et al. 2025: Chitosan hydrochloride coated and nonionic surfactant modified niosomes: a better way for oral administration of semaglutide, Biomed Materials. 20(3):38.