In Vitro and In Vivo Assessment of Darolutamide Encapsulated Lipid-Extruded PEGylated Liposomal Formulation

Darolutamide (DA), a non-steroidal androgen receptor inhibitor, has emerged as a promising therapeutic agent for non-metastatic castration-resistant prostate cancer (nmCRPC); however, its clinical utility is limited by poor aqueous solubility and the need for high therapeutic doses. To address these challenges, PEGylated liposomes encapsulating darolutamide (DALP) were developed to improve its pharmacokinetic profile and enhance anticancer efficacy through sustained drug release. The optimized DALP exhibited a mean particle size of 107.4 ± 5.2 nm, a polydispersity index of 0.1505 ± 0.02, and a zeta potential of −19.34 ± 1.63 mV, indicating good stability and uniformity. High encapsulation efficiency (89.2 ± 0.23%) and drug loading capacity (6.67%) were achieved. In vitro release studies demonstrated a controlled and sustained release profile of DA from the liposomal system. Cytotoxicity assays revealed a 2.24-fold reduction in IC 5 0 for DALP compared to free DA, indicating enhanced antiproliferative activity. Furthermore, DALP showed significantly increased apoptotic induction and greater inhibition of cell invasion and colony formation in PC-3 prostate cancer cells. Notably, enhanced apoptosis was also observed in 3D multicellular tumor spheroids, suggesting improved therapeutic performance in physiologically relevant tumor models. Pharmacokinetic studies demonstrated a 1.98-fold prolongation in plasma half-life and a 4.04-fold increase in mean residence time (MRT) relative to free DA. Biodistribution analysis showed minimal off-target organ accumulation, and acute toxicity studies confirmed the safety of the formulation. Overall, PEGylated liposomal delivery of darolutamide offers a promising nanocarrier strategy for prolonging systemic circulation, improving therapeutic efficacy, and reducing systemic toxicity, thereby providing an advanced approach for nmCRPC treatment.