Anti-inflammatory effects and acute oral toxicity of Copaifera spp. essential oil-loaded nanoemulsion

Abstract

Copaifera spp. essential oil (EOC) was extracted by hydrodistillation of Copaifera oleoresin (COR). The EOC was characterized by GC/MS and a novel EOC-loaded nanoemulsion was developed to enhance the EOC solubility and to evaluate its utility as antinflammatory. EOC contain 14 volatile compounds (including β-caryophyllene: 51.52%) having a required HLB of 11. The Surfactant: EOC: Water ratio of 13:15:75 (%, w:w:w) produced the optimal formulation (particle size: 94.47 nm). The EOC-loaded nanoemulsion presented a pseudoplastic/thixotropic behavior with excellent shelf stability for 6 months. The anti-inflammatory effect of the nanoemulsion was more potent than that of the EOC, and statistically equal to diclofenac (50 mg/kg). The EOC-loaded nanoemulsion showed no oral acute toxicity (in mice) at 2000 mg/kg; hence, it is considered a nontoxic product. The development of the EOC-loaded nanoemulsion added value to both the COR and the EOC by providing a suitable formulation that could be used as an anti-inflammatory product.