Producing chitosan derivatives useful in cosmetic or pharmaceutical compositions comprises reacting chitosan having defined properties with a carboxymethylating agent and reducing the resulting imine

摘要

Producing chitosan derivatives comprises reacting chitosan with a carboxymethylating agent and reducing the resulting imine. Either the chitosan has a weight-average molecular weight (Mw) of 50000-160000 and/or a degree of acetylation (DA) of at least 12% or the chitosan has a Mw and/or DA such that a 1% solution of the chitosan in 1% aqueous acetic acid has a viscosity of 4 mm2>/s at 25[deg]C. Independent claims are also included for: (1) chitosan derivatives of formula (I); (2) cosmetic or pharmaceutical composition containing (I); (3) cosmetic treatment for care, cleansing or make-up of keratinic materials by applying a composition as above. x : 12-27; y : 60-81; z : 3-17; x+y+z : 100.