(M1330-07-40) Enteric Coating and Evaluation of Optimized Curcumin-Loaded Nanostructured Lipid Carriers

Purpose: Curcumin (CUR) is a polyphenol extracted from turmeric roots. It has a variety of pharmacological activity, such as anti-inflammatory, anti-bacteria, anti-cancer, and anti-alzheimer's. However, CUR has a very low solubility in the acidic environment due to large particles and fat-soluble ingredients. In addition, there is a disadvantage that it is quickly metabolized with curcumin sulfate and curcumin glucuronide and is absorbed only 1% in oral administration. In this study, to overcome the limitations of CUR, nanostructure lipid carriers (NLC) and enteric coating were used to improve bioavailability and increase absorption of CUR.

Methods: The optimization was performed by using the Box-Behnken design and each factor was set as total lipid amount, liquid lipid ratio, and surfactant percentage. The response was the particle size, polydispersity index and the encapsulation efficiency (EE). CUR-NLC was prepared using the hot homogenization method and was coated with Eudragit S100 (EUD) using the solvent evaporation method.

Results: The optimized total lipids were 300 mg, the ratio of the liquid lipid was 80%, the surfactant was 1.35%, the paricle size was 157.8 ± 2.15 nm, the polydispersity index was 0.125 ± 0.02, and the EE was 97.5 ± 0.04%. The error rate for the response was less than 10%. TEM image showed the spherical shape corresponding to the particle size. Differential scanning calorimetry, Fourier transform infrared spectroscopy, and X-ray diffractometer were carried out that there were no chemical bonds in the manufacturing process and proved that CUR was successfully encapsulated. In EUD-CUR-NLC released 58.64% of CUR in pH 6.8 buffer, about 2.7 times compared to pH 1.2. In the Caco-2 cells, the IC₅₀ of EUD-CUR-NLC was 9.156 µg/mL in 24 h, 7.534 µg/mL in 48 h.

Conclusion: Curcumin-loaded nanoparticles with small particle size, PDI, and high EE were optimized through the Box-Behnken design. Based on the in vitro release test results, it was concluded that the enteric coating of curcumin-loaded NLCs was successfully prepared.

References: 1. Lee, Hyeonmin, et al. "Development and Evaluation of Tannic Acid-Coated Nanosuspension for Enhancing Oral Bioavailability of Curcumin." Pharmaceutics 13.9 (2021): 1460.
2. Mishra, Rakesh Kumar, et al. "Lipid-based nanocarrier-mediated targeted delivery of celecoxib attenuate severity of ulcerative colitis." Materials Science and Engineering: C 116 (2020): 111103.