Abstract 2193: Stabilityof injectable phospholipid nanoparticles loaded with paclitaxel: influence oflipid composition, drug concentration, storage temperature, lyophilization, andadditives

Paclitaxel is one of the most effective chemotherapeutic drugs for solid tumors including breast, lung and ovarian cancers. It has been formulated as a nanoparticle formulation, Abraxane, to improve its solublity (0.35-0.7 μg/mL) and to avoid the use of harmful solvents like cremophor EL. We previously reported the next-generation Abraxane - Cynviloq - a polymeric micelle paclitaxel formulation which uses a chemical polymer instead of biological polymer to stabilize the nanoparticle [1]. Here we investigate and report the use of phospholipids instead of a chemical polymer for the creation of the next-generation Abraxane. The effect of lipid composition on drug loading and physical stability of paclitaxel-loaded lipid-coated nanoparticle formulation was evaluated before and after lyophilization. The nanoparticles were prepared by microfluidization-solvent evaporation method. The formulation parameters included type of phospholipids, phospholipid fatty acid chain length, ratio of phospholipid and lysophospholipid combination, and drug-phospholipid ratio. The process parameters such as microfluidization pressure and number of microfluidization cycles were studied and their impact on drug loading, particle size and physical stability were evaluated. The short-term stability evaluation of nanoparticles prepared with different phospholipid ratios demonstrated that 4:1 as the optimum phospholipid-lysophospholipid ratio to achieve a loading of more than 60% paclitaxel with particle size of approximately ∼200nm. The nanoparticle size increased with an increase of carbon chain length of the phospholipid fatty acid, but no significant trends were observed for drug loading with changes in microfluidization pressure or number of cycles. The stability of the formulation was evaluated at different temperatures before and after lyophilization. The optimization of phospholipid composition, drug-lipid ratio, process parameters and additives for stability on lyophilization led to a physically stable paclitaxel-loaded phopholipid-coated nanoparticulate formulation that maintains size, charge and particulate integrity during storage. Phospholipid bound paclitaxel nanoparticle was successfully manufactured in lab scale with the desired properties. Scaling up and additional work-up for clinical evaluation is being evaluated. Reference: 1. Motamed K, Goodman Y, Hwang L, Hsiao C, Trieu V. (2014). IG-001 - A non-biologic nanoparticle paclitaxel for the treatment of solid tumors. J