RESUMO
ABSTRACT The value of propolis is scientifically and commercially measured through the content of biologically active molecules as phenolic compounds and flavonoids; on the other hand, a high percentage of waxes in the propolis composition makes it a substandard beekeeping product. Colombian propolis is characterized by a high content of waxes; however, this drawback turns into an advantage when this material is used for preparing lipid nanocarriers. Accordingly, in this research work, a propolis-extracted material obtained by Randall method is characterized by differential scanning calorimetry, infrared spectroscopy, X-ray diffraction, and 1H-Nuclear Magnetic Resonance. Then, it is used for obtaining nanostructured lipid carriers by the emulsification-diffusion technique, whose recipe and operating work conditions were established by a Plackett-Burman statistical screening design. The obtained particles exhibit sizes less than 300 nm, polydispersity indices around 0.1, zeta potential values less than ±2 mV, good physical stability and they show to be safe in the in vitro irritation test. Thus, Colombian propolis arises as an attractive natural source for obtaining lipid carriers that could be used in pharmaceutical or cosmetic industries for developing innovative products.
RESUMO
En el ámbito cosmético, la tecnología a escala nanométrica resulta atractiva para el diseño de productos novedosos y funcionales. Así, para el caso de las nanopartículas lipídicas, se ha demostrado su capacidad para incrementar la estabilidad de moléculas activas y modificar su liberación. Como un aporte en la búsqueda de alternativas innovadoras para la preparación de este tipo de transportadores (carriers), el presente trabajo propone el aprovechamiento de las ceras provenientes de propóleos para la preparación de partículas lipídicas conteniendo extracto del árbol de té. Las partículas obtenidas presentan tamaños cercanos a 200 nm con polidispersidades inferiores a 0,1. Los valores de potencial zeta cercanos a cero sugieren un mecanismo de estabilización del sistema particulado vía efecto estérico. De otro lado, la incorporación del activo dentro de la estructura de las partículas es confirmada por DSC. En conjunto, los resultados evidencian la posibilidad de generar valor agregado a un producto de la colmena reconocido y valorado por sus propiedades biológicas. Además, ofrecen un material de partida que constituye una alternativa interesante para el desarrollo de productos cosméticos novedosos en los que podrían incorporarse moléculas activas.
In the cosmetic field, the technology at the nanometric scale is attractive for designing novel and functional products. In the case of lipid nanoparticles, the ability of these carriers for increasing the stability of active molecules and modifying their release has been demonstrated. As a contribution in the research of innovative alternatives for preparing these particles, this work proposes the use of the propolis waxes as starting material. In this way, lipid nanoparticles containing tea tree oil were prepared having particle sizes close to 200 nm with polydispersity indexes less than 0.1. The zeta potential values near to zero suggest the stabilization of the lipid nanoparticles via steric mechanisms. The incorporation of the active into the nanoparticle structure is confirmed by DSC. As a whole, the results are appealing in order to give added value to beehive product, recognized in Latin America for its biological properties. Furthermore, these results offer a new alternative of lipid material which is interesting for developing pioneering cosmetic products containing active molecules.