1. A pharmaceutical formulation for use in the treatment of breast cancer by intra-muscular injection, wherein the pharmaceutical formulation comprises fulvestrant, a pharmaceutically-acceptable alcohol being a mixture of 10% weight of ethanol per volume of formulation and
10% weight of benzyl alcohol per volume of formulation, and the formulation contains 15% weight of benzyl benzoate per volume of formulation and a sufficient amount of a ricinoleate vehicle so as to prepare a formulation of at least 45 mg/ml-1 of fulvestrant, wherein the
ricinoleate vehicle is castor oil, and wherein the total volume of the
formulation