RESUMEN
This study aimed to optimize Cymbopogon citratus essential oil loaded into PLGA-nanoparticles by investigating the effect of processing variables (sonication time, ultrasound power, and essential oil/polymer ratio) on encapsulation efficiency and particle mean hydrodynamic diameter using Box-Behnken design. Nanoparticles were prepared by an emulsification/solvent diffusion method and physicochemically characterized by FTIR, DSC and TGA/DTA. Cytotoxicity was evaluated in human HaCat keratinocytes by WST-1 and LDH assays. The optimized formulation had a hydrodynamic mean diameter of 277â¯nm, a polydispersity index of 0.18, a Zeta potential of -16â¯mV and an encapsulation efficiency of 73%. Nanoparticle characterization showed that only citral was incorporated in nanocarriers, with some amount adsorbed on their surface, and highlighted the potential in increasing the oil thermal stability. The drug release profile demonstrated a biphasic pattern with a substantial sustained release depending on diffusion from the polymeric matrix. Toxicity effects on cell viability of pure essential oil at low concentrations were significantly eliminated when encapsulated. Results revealed the ability of PLGA-nanoparticles to improve essential oil physicochemical characteristics, by controlling release and reducing toxicity, suggesting their potential use in pharmaceutical preparations.
Asunto(s)
Nanopartículas/química , Aceites Volátiles/farmacología , Ácido Poliglicólico/química , Línea Celular , Membrana Celular/efectos de los fármacos , Supervivencia Celular/efectos de los fármacos , Cymbopogon/química , Portadores de Fármacos/química , Liberación de Fármacos , Humanos , Cinética , Aceites Volátiles/química , Tamaño de la Partícula , Propiedades de SuperficieRESUMEN
Abstract This study aimed to prepare hydrogel containing Cymbopogon citratus (DC.) Stapf, Poaceae, volatile oil encapsulated in poly (d,l-lactide-co-glycolide) nanoparticles and to evaluate its in vitro anti-herpetic activity. Polymeric nanoparticles were prepared by solvent emulsification-diffusion method and incorporated in carbomer hydrogels. In vitro release profiles for the nanogel, loaded nanoparticles and hydrogel containing free oil were evaluated by dialysis. Inhibitory activities against Herpes simplex for the formulations were investigated in Vero cells. Hydrogel was developed using nanoparticles with mean diameter of 217.1 nm and negative Zeta potential (−20.5 mV). Volatile oil release profile showed a biphasic pattern with an initial faster release and subsequent sustained phase in all formulations. Nanogel strongly inhibited virus in a non-cytotoxic concentration, 42.16 times lower than free oil, 8.76 and 2.23 times than loaded nanoparticles and hydrogel containing free oil, respectively. These results highlight the potential of nanogel to protect oil against volatilization, control release and improve its anti-herpetic activity.