US Patent 8361446 Use of benzotriazole derivatives for photostabilisation

Use of benzotriazole derivatives of formula (1), wherein R1 is C1-C30alkyl; C1C5alkoxy; C1-C5alkoxycarbonyl; C5-C7cycloalkyl; C6-C10aryl; aralkyl; —SO3M; a radical of formula (1a) R3 is hydrogen; C1C5alkyl; C1C5alkoxy; halogen, preferably Cl; or hydroxy; R4 and R5 are each independently of the other hydrogen; or d-C5alkyl; m is 1 or 2; n is O or 1; if m=1, R2 is hydrogen; unsubstituted or phenyl-substituted d-C1-C12alkyl; or C6-C10aryl; if m=2, R2 is the direct bond; or —(CH2)p—; and p is 1 to 3; for enhancing the photostability of cosmetic or dermatologic compositions comprising at least one further organic UV absorber.