| abstract |
The present invention provides a solution, suitable for use in pharmaceutical or cosmetic compositions, comprising a) 1-40 % by weight of a compound having formula (1), in which R1, R2 and R3, independently, are H, OH, C1-C18alkoxy, NH2, NH-R4 or N(R4)2 in which R4 is C1-C18alkyl, OR4 in which R4 has its previous significance, phenyl, phenoxy or anilino, or pyrrolo, in which the respective phenyl or pyrrolo moieties are optionally substituted by one, two or three substituents selected from OH, carboxy, C1-C18alkyl or -alkoxy, C1-C18carboxyalkyl, C5-C8cycloalkyl, a methylidenecamphor group, a group -(CH=CH)nC(=O)-OR4 in which n is 0 or 1 and R4 has its previous significance or a group (a) or the corresponding alkali metal, ammonium, mono-, di- or tri-C1-C4alkylammonium, mono-, di- or tri-C2-C4alkanolammonium salts, or the C1-C18alkyl esters thereof; dissolved in b) a solvent selected from i) a C1-C8alkyl ester of a (hydroxy)polycarboxylic acid, with the exclusion of dioctyl malate; ii) a butylether; iii) an ester of a butyl ether; iv) an alcohol; v) a Guerbet alcohol; and vi) a di-(C1-C4alkyl)amide of an arylcarboxylic acid. |