A process for preparing a base formulation for a dermatological sunscreen composition comprising base formulations comprising oil and water phases and containing a plurality of UV-absorbing substances and at least one amphiphilic substance which forms lamellar structures.本發明提供一種製備包含起始製劑之皮膚防曬組成物之起始製劑之方法,該起始製劑包含油相及水相,並含有複數種UV吸收性物質及至少一種形成層狀結構之兩親媒性物質。