The aqueous thermosetting neutralized chitosan composition, forming a phosphate-free transparent hydrogel at a temperature higher than 5°C, comprises 0.1 to 5.0 w/w %, based on the total composition, of a reacetylated chitosan having a molecular weight of not smaller than 100 kDa and a deacetylation degree of 40 to 70 %, neutralized with an hydroxylated base, and 1 to 30 w/w %, based on the total composition, of a complexing agent selected from polyoses and polyols derived from polyoses. Said composition is useful for the preparation of an injectable formulation.
