The subject of the present invention is a liposomal formulation containing an anti-tumour compound characterised in that it contains the active compound encapsulated in liposome vesicles forming a composition of lipid components in the ratio of 1 part by mass of the active compound per 5 parts by mass of the lipid components, preferably 1 part by mass of the active compound per 5 parts by mass of the lipid components as well as a vitamin or a derivative thereof, a method of producing it as well as composition containing the said formulation.本発明の主題は、抗腫瘍化合物を含むリポソーム製剤であって、活性化合物を、脂質成分の組成物を形成するリポソームベシクルに封入された状態で、脂質成分5質量部当たり活性化合物1質量部、好ましくは脂質成分5質量部当たり活性化合物1質量部の比率で含むとともに、ビタミン又はその誘導体を含むリポソーム製剤、その製造方法、並びに斯かる製剤を含む組成物である。【選択図】なし