(371) Development of a High-Concentration Fulvestrant Depot Formulation with Sustained Release Properties
Introduction: Fulvestrant is a selective estrogen receptor degrader used in the treatment of ER-positive, HER2-negative breast cancer. The current oil-based sustained-release formulation requires two 5 mL intramuscular injections (250 mg/5 mL each) due to its poor solubility, often causing injection-site pain, discomfort, and reduced patient compliance. To address this limitation, we developed a high-concentration formulation (500 mg/5 mL) with enhanced solubility and a comparable PK profile, enabling a single 5 mL injection. This approach aims to reduce patient burden and potentially improve adherence.
Learning Objectives:
Describe the formulation strategy and interpret PK data to assess fulvestrant depot bioequivalence.
Identify key formulation and study design factors for sustained-release intramuscular injections.
