wherein the formulation comprises fulvestrant dissolved in a ricinoleate vehicle, a pharmaceutically acceptable non-aqueous ester solvent, and a pharmaceutically acceptable alcohol, and wherein the formulation is
adapted for attaining a therapeutically significant blood plasma
fulvestrant concentration for at least 2 weeks.
2. Use of fulvestrant in the preparation of a pharmaceutical formulation for the treatment of breast cancer by intra-muscular administration to human patients, wherein the formulation comprises fulvestrant in solution,