Preparation and Characterization of Nanoemulsion Containing a Natural Naphthoquinone

Abstract

publicado na web em 07/06/2018 Natural naphthoquinones such as lapachol (Lp) have demonstrated promising biological activities. However, these quinones present low systemic biodisponibility due to its poor aqueous solubility. To overcome this problem, nanoemulsions (NE) formed by oily core are able to incorporate hydrophobic molecules thus enabling them to be dispersed into an aqueous phase. The present study reports the development, characterization, and physical stability of NE containing lapachol. NE formulations (F1, F2, F3, F4, and F2-Lp) were prepared using emulsion phase inversion (EPI) method and characterized in relation to droplet size, size distribution (PDI), zeta potential, and physical stability. The formulation chosen to incorporate lapachol (F2-Lp) showed droplet size in nanometric scale with homogeneous size distribution (PDI < 0.2) and negative zeta potential (about −30 mV). In addition, good physical stability of F2 and F2-Lp was demonstrated using analytical centrifugation with photometric detection where the light transmission profiles did not change throughout the dispersions. Nanoemulsion containing lapachol presented a strong reddish aspect; however, the incorporation of this naphthoquinone did not alter the main physicochemical parameters of NE formulation. The in vitro release study demonstrated a sustained release profile from NE with about 60% of lapachol released within 54 h.

Nanoemulsion of Minthostachys verticillata essential oil. In-vitro evaluation of its antibacterial activity

“…The in vitro release experiments of the EO were carried out using the dialysis technique ( Rodrigues et al., 2018 ). An aliquot of nanoemulsion was placed inside a dialysis bag (cellulose membrane, molecular weight cut-off 14,000 Da, Roth®), sealed, and immersed in a vessel containing 150 mL of 10 mM phosphate buffer solution (PBS, pH 7.4).…”

Synthesis and Technology of Nanoemulsion-Based Pesticide Formulation

“…The use of a surfactant is believed to alter the electrostatic charge in the nanoemulsion which causes low aggregation [19]. The influence of single and complex surfactants in nanoemulsion formation has been studied previously [20]. Some studies have demonstrated mixed surfactant is capable to produce better hydrophilic-lipophilic balance (HLB), enhances the flexibility of the surfactant layer and ability to partition at high levels into the oil-water interface.…”

Nanoemulsion Stabilized by Safe Surfactin from Bacillus subtilis as a Multifunctional, Custom-Designed Smart Delivery System

“…The samples were stored at 25 °C for 195 days and then their stability was evaluated based on the particle size (D H ), particle size distribution and zeta potential. The literature data indicate that sufficiently high and sufficiently low potential zeta values (up to 30mV and below −30mV, respectively) enhance the stability and functionality [ 37 , 38 , 39 ]. Unfortunately, the storage period had a destructive effect on the systems with solubilized curcumin in CA—flocculation was observed, while systems with Vit C and Vit E remained clear, with slight opacity.…”