The present invention relates to the modification of hyaluronic acid (HA) with aryl/alkyl succinic anhydrides (ASA) to produce aryl/alkyl succinic anhydride HA derivatives, to the derivatives as such, and to their applications and uses, particularly in the cosmetic and biomedical industries. The ASA-HA derivatives are expected to have interesting properties that can be used for advanced formulation (bind stronger to the skin compared to non-modified HA), possibly also in delivery systems for actives or drugs by encapsulation (nano/micro capsules) or formation of nano/micro spheres. Further, the low MW ASA-HA derivatives are expected to penetrate the skin more efficiently than non-modified HA of the same MW.