Effects of stabilizers and nanostructured lipid carrier entrapment on photostability of curcumin and capsaicin in extract mixture

Abstract

Nowadays, natural extracts are increasingly being used in cosmetics due to their antioxidant, anti-aging, and anti-cellulite properties. Chili peppers (Capsicum spp.) belong to the Solanaceae family. The main component of chili peppers is capsaicin. Turmeric (Curcuma longa) belongs to the Zingiberaceae family. The main component of turmeric is curcuminoids, especially curcumin. Previous studies have shown that capsaicin is unstable when exposed to light, while curcumin can be degraded by light and alkaline solutions. As a result of this problem, there are limitations to the use of these compounds in cosmetics. Therefore, this research aimed to solve this problem by increasing the stability of both extracts using antioxidants, natural sunscreen, and the delivery system on increasing the stability of chili and turmeric extracts. The half-lives of single extracts, mixed extracts, and extracts in the delivery system were evaluated after UV and white light exposure for 0, 4, and 8 h. Then the amount of active ingredients was evaluated using high-performance liquid chromatography. The results showed that chlorogenic acid was effective increasing the photostability of capsaicin in chili extract from a half-lives of 6.79 ± 0.18 h to 16.50 ± 1.11 h and increasing the photostability of curcumin in turmeric extract from a half-lives of 9.53 ± 1.51 h. to 19.25 ± 1.23 h. In addition, the use of natural sunscreen or sunflower oil also increased the half-lives of chili extract and turmeric extract to 23.10 h. Then the mixed extracts were entrapped in a nanostructured lipid carrier (NLC) delivery system. The compositions of NLCs were comprised of glyceryl distearate as a solid lipid, isopropyl myristate, sunflower oil, and olive oil as liquid lipids. The surfactants were polysorbate 80 and sorbitan 80. The formulation was prepared using a high-shear homogenizer at 20,000 rpm for 15 min. The resulting formulation possessed particle sizes of 152.63±2.41 nm, the polydispersity index was 0.21±0.06, and the zeta potential was -60.27±1.56 mV. The entrapment efficiency of chili extract and turmeric extract was 95.94 ± 0.05% and 97.79 ± 0.36%, respectively. The stability of the extract was increased when prepared in a nanostructured lipid carrier delivery system. Half-lives of chili extract was increased to 38.50 ± 0.14 h and half-lives of turmeric extract was increased to 57.75 ± 1.96 h. Therefore, chlorogenic acid, sunflower oil, and nanostructured lipid carrier delivery system can increase the photostability of curcumin and capsaicin in the extract mixtures.