Development and Evaluation of Talazoparib Nanoemulsion for Systemic Therapy of BRCA1-mutant Cancer.

AIM: This is a debut study report on talazoparib (BMN-673)-loaded nanoemulsion (TZNE) for parenteral administration. MATERIALS AND METHODS: TZNE (0.05% drug, 151.4±0.7 nm droplet size, polydispersity index of 0.120±0.010 and zeta potential of -33.30±1.22 mV) was designed, developed and characterized using in vitro studies. A cumulative in vitro release study was performed in physiological phosphate buffer solution at different pH (5.3, 6.5 and 7.4) using a dialysis method. Cytotoxicity and apoptosis assays were performed on MDA-MB-231, NCI/ADR-RES, 2008 C13, CP-70 and SKOV-3 cell lines using CellTiter® Blue. Quantitative and qualitative cell uptake was studied using fluorescent probe, coumarin-6 (C-6). RESULTS: The drug release form TZNE nanoemulsion was slow and sustained for 24 h. Cytotoxicity and apoptosis were found to be concentration-dependent. The half-maximal inhibitory concentration of TZNE was 0.4852 and 1.35, 11.757 and 0.4696, and 1.169 and 0.7235 µM in MDA-MB-231, SKOV-3 and NCI/ADR-RES cells with 48 and 72 h incubation, respectively. Cellular uptake studies using fluorescent probe, coumarin-6 C-6, showed higher cellular uptake of TNZE compared with free C6. Results suggest that nanoemulsion could provide a new platform for systemic delivery of talazoparib.