Enhancing high-temperature stability of limonene-loaded nanostructured lipid carriers with various solid lipids

Abstract

In this research, nanostructured lipid carriers (NLCs) loaded with limonene were developed using various solid lipids. The impact of high temperatures on the characteristics of NLCs was investigated. NLCs exhibited zeta potential values exceeding |30| mV, indicating excellent homogeneity and stability. Increasing the carbon chain length of monoglycerides from C15 to C21 resulted in a corresponding increase in particle size of NLCs from 219.1 ± 1.1 to 243.3 ± 0.9 nm. However, the particle size remained relatively constant with an increase in the number of solid lipid carbon chains. Encapsulation efficiency of limonene increased from 66.0 ± 0.7% to 86.2 ± 0.8% with an increase in the number of solid lipid carbon chains. The result showed that more ester bonds facilitated the dissolution of the target and enhanced the interaction forces between solid lipids and the target. X-ray diffraction, Fourier transform-infra-red spectroscopy and differential scanning calorimetry analyses confirmed effective encapsulation of limonene in NLCs, resulting in good stability. NLCs prepared from various solid lipids exhibited varying properties. Glycerol triglyceride demonstrated superior stability and homogeneity of nanoparticles under high-temperature conditions compared to other solid lipids. This study provides enhancing the thermal stability of limonene-loaded NLCs and proposes a novel approach for their practical application.