Topically applicable, stable, UV-photoprotective cosmetic/dermatological compositions well suited for the photoprotection of human skin and/or hair against the damaging effects of UV-A and UV-B irradiation, comprise (a) an effective UV-photoprotecting amount of at least one dibenzoylmethane UV-sunscreen compound and (b) an effective dibenzoylmethane compound (a) photostabilizing amount of at least one benzalmalonate silane having the structural formula (I): ##STR1##

As composições tòpica aplicáveis, estáveis, uV-photoprotective-photoprotective de cosmetic/dermatological jorram servido para o photoprotection da pele humana e/ou o cabelo de encontro aos efeitos prejudiciais do irradiation de UV-A e de UV-B, compreende (a) um uma quantidade uV-photoprotecting-photoprotecting eficaz ao menos de um composto uV-sunscreen-sunscreen do dibenzoylmethane e (b) uma quantidade photostabilizing do composto do dibenzoylmethane (a) eficaz ao menos de um silane do benzalmalonate que tem a fórmula estrutural (i): ## do ## STR1