Preparation and Characterization of Pazopanib Hydrochloride-Loaded Four-Component Self-Nanoemulsifying Drug Delivery Systems Preconcentrate for Enhanced Solubility and Dissolution

The aim of this study was to develop a four-component self-nanoemulsifying drug delivery system (FCS) to enhance the solubility and dissolution of pazopanib hydrochloride (PZH). In the solubility test, PZH showed a highly pH-dependent solubility (pH 1.2 > water >> pH 4.0 and pH 6.8) and was solubilized at 70 °C in the order Kollisolv PG (5.38%, w/w) > Kolliphor RH40 (0.49%) > Capmul MCM C10 (0.21%) and Capmul MCM C8 (0.19%), selected as the solubilizer, the surfactant, and the oils, respectively. In the characterization of the three-component SNEDDS (TCS) containing Kolliphor RH40/Capmul MCM C10, the particle size of dispersion was very small (<50 nm) and the PZH loading was 0.5% at the weight ratio of 9/1. In the characterization of FCS containing additional Kollisolv PG to TCS, PZH loading was increased to 5.30% without any PZH precipitation, which was 10-fold higher compared to the TCS. The optimized FCS prepared with the selected formulation (Kolliphor RH40/Capmul MCM C10/Kollisolv PG) showed a consistently complete and high dissolution rate (>95% at 120 min) at four different pHs with 1% polysorbate 80, whereas the raw PZH and Kollisolv PG solution showed a pH-dependent poor dissolution rate (about 40% at 120 min), specifically at pH 6.8 with 1% polysorbate 80. In conclusion, PZH-loaded FCS in this work demonstrated enhanced solubility and a consistent dissolution rate regardless of medium pH.