(W1130-04-20) A Nano-Emulsion-Based Formulation of Sorafenib for Oral Bioavailability Enhancement and Repurposing against Non-small Cell Lung Cancer (NSCLC)

Purpose: Lung cancer is one of the major fatal cancers in the United States, accounting for about 13% of all cancer cases. Non-Small Cell Lung Cancer (NSCLC) is about 85% of all Lung Cancer cases. NSCLC has a low 5-year survival rate for the patients based on its diagnosis either at the local stage (63%) distant stage (8%) or regional stage (35%). Current therapies include chemotherapeutic agents, targeted therapy, anti-angiogenic therapy, and immunotherapy which play a vital role in lung cancer treatment. However, these therapies are not without limitations such as resistance to the treatment, toxicity, and high cost. To address these limitations, repurposing drugs like kinase inhibitors that are effective towards NSCLC is needed. Our research group has previously established the efficacy of Sorafenib against NSCLC by formulating polymeric nanoparticles for localized effect. In this study, we aim to develop a patient complaint approach by formulating an oral nanoemulsion of sorafenib (SF) to improve its solubility and bioavailability.

Methods: Sorafenib (SF) nanoemulsion (SF-NE) was developed using low-energy and water titration methods. The compatibility of the components oil: Capmul MCM, surfactant: Tween-20, co-Surfactant: Transcutol HP, and water was assessed by preparing blank formulations. Further Pseudo-ternary phase diagrams were established for different Surfactant-Co-Surfactant (Smix) ratios: 1:1, 1:2, 2:1, and 3:1 to determine the Smix right ratio between the components (Fig. 1). The required drug (SF) was mixed with the Capmul MCM (oil) at 70⁰C at 1,000 rpm until the drug was completely solubilized in the oil. Surfactant and Co-Surfactant were added to the above mixture in a 3:1 Smix ratio to form a transparent homogeneous mixture. Water was added dropwise (Qs 2 mL) and mixed at 1,000 rpm for a few minutes until a stable nanoemulsion was formed. The prepared formulation was evaluated for physicochemical parameters such as particle size, zeta potential, polydispersity index, entrapment efficiency, and thermodynamic stability. The successful formulation was analyzed for particle morphology using TEM analysis. Further, the efficacy of SF-NE will be evaluated on NSCLC cell lines and the oral permeability assessment will be performed on Caco2 Cell lines.

Results: The pseudo-ternary diagrams were plotted to assess the NE region in different Smix ratios. Based on the ternary plots we observed (Fig.1C) has the biggest NE area and hence was chosen for further optimization. We prepared a total of 8 SF-NE formulations by varying the oil content and Smix ratio, and optimized formulation T-8 (Fig. 2A). The physicochemical characteristics of the optimized SF-NE (T-8) yielded a particle size of 41.6±22.7 nm, polydispersity index of 0.39±0.10, zeta potential of –4.7±2.0 mV, drug entrapment of 88.01±5.6 % (i.e., loading of 2 mg/ml formulation) with no phase separation (Fig. 2B). The TEM images indicate particle size morphology and droplet size of the optimized formulation (Fig. 2C). Further, the optimized formulation (T-8) was subjected to thermodynamic stability, which included six freeze-thaw cycles between 40°C and –20°C. As can be seen in (Fig. 3), the particle size was 52.5±6.6 nm, the polydispersity index was 0.35±0.04, zeta potential of –10.6±2.7 mV, entrapment of 93.0±3.0%, and % transmittance of 92.0±0.7% with no signs of physical instability. The formulation was also subjected to centrifugation at 4°C, 21,000×g for 20 minutes, which yielded a particle size of 73.8±1.7 nm, polydispersity index of 0.5±0.02, zeta potential of –10.7±0.9 mV, entrapment of 93.4±3.4%, and % transmittance of 94.9±0.8% (Fig. 3). Thermodynamic stability results show that the optimized formulation had higher stability and showed no signs of creaming, or drug precipitation.

Conclusion: The current study focuses on developing an oral nanoemulsion for Non-Small Cell Lung Cancer using a kinase inhibitor (Sorafenib). The data indicates successful development of SF-nanoemulsion with particle size below 100 nm, high encapsulation value >80%, and high thermodynamic stability. Further studies on the SF-nanoemulsions are currently being conducted to see the cell viability against the Non-Small Cell Lung Cancer cell lines. 2D and 3D in-vitro assays are required to establish the efficacy of the SF-nanoemulsion. Since this study aims to develop an oral formulation, in-vitro permeability studies will be performed on the Caco2 cells to predict the in-vivo oral absorption of the SF-nanoemulsion.

Figure 1. Representative images of Pseudo ternary phase diagrams of A) Smix ratio 1:1 B) Smix ratio 1:2 C) Smix ratio 3:1 D) Smix ratio 2:1.


Figure 2. Representative images of A) SF-NE optimization trials with 2mg/ml SF B) Physicochemical characterization of T-8 C) TEM Images of T-8


Figure 3. A) Thermodynamic Stability of T-8 (Centrifugation) and (Freeze-thaw cycle)