A stable galenic composition of. a compound of general formula (I) wherein R1 and Rp both represent independently of each other an alkyl, aryl, arylalkyl group, optionally substituted with one or more linear or branched groups, optionally bearing one or more heteroatoms, comprising said compound of formula I in an amount ranging from 0.01 to 15% eby weight based on the total weight of the final composition, - at least one anhydrous ester, the main chain and/or optionally the branched chains of which are free from free and/or reactive groups or functions, in an amount ranging from 0.1 to 99.9% by weight based on the total weight of the cosmetically and pharmaceutically acceptable composition, and - optionally a cosmetically and pharmaceutically acceptable excipient for completing the 100% of the total weight of the composition.
