Hello, to maintain viscous properties in an organic, you might consider using ethyl cellulose (freely soluble in ethanol, methanol, toluene, chloroform, and ethyl acetate, according to PUBCHEM) or hydroxypropyl methylcellulose instead of chitosan.

Or you can try modified forms of Chitosan, like acylated, alkylated or trimethylated, which are more hydrophobic.