Effect of Peppermint Oil on the Characteristics and Physical Stability of Nanostructured Lipid Carrier-CoQ10

Peppermint oil (PO) is one of the essential oils used as a enhancer in nanostructured lipid carriers (NLC), which affects the characteristics and stability of NLC. This study was aimed at determining the effect of PO on the characteristics and stability of NLC-coenzyme Q10 (NLC-CoQ10). NLC containing 1% CoQ10 was added to various concentrations (0, 1, 1.5, and 2%) of PO, namely F1-F4, respectively. The characteristics (odour, shape, viscosity, pH, particle size, and polydispersity index) of F1, F2, F3, and F4 were determined. Physical stability, centrifugation, and thermal cycle tests were performed. The results showed that adding 1-2% PO caused NLC-CoQ10 to have a distinctive PO odour, a spherical shape, and viscosity values of 329.1±10.5, 307.6±27.4, 220.4±4.0, and 219.9±2.2 cps for F1, F2, F3, and F4, respectively. The pH values ranged from 6.33 to 6.36, while the particle sizes were 188.25±13.22, 197.80±14.19, 190.90±9.47, and 187.50±8.71 nm, respectively. The polydispersity index was below 0.3; and the zeta potential values ranged from –44.30 mV to –52.74 mV. F1, F2, and F3 remained stable after 30 days, whereas F4 became more fluid. The formulas performed well in a centrifuge test. The F2, F3, and F4 thermal cycle tests were all stable, but the F1 separated in the first cycle. The addition of 1, 1.5, and 2% PO did not affect the spherical morphology, the pH value, particle size, or the polydispersity index. The addition of 1.5 and 2% PO reduced viscosity, while the addition of 1 and 1.5% reduced zeta potential but increased stability.