RESUMO
The use of layer-by-layer (LbL) deposition technique allows materials, such as drugs, to be self-assembled in multilayers with other electrolytes by combining their properties in a nanostructured system. Triclosan (TCS) is commonly used as a drug because of its bactericidal action, while erythrosine (ERY) has been used as a photosensitizer in photodynamic therapies because of its high light absorptivity in the visible region of the electromagnetic spectrum. The major advantage of investigating systems immobilized in LbL films is the benefit of characterizing the interaction through available substances in solid state techniques. It was possible to immobilize in LbL films, ERY, and ERYâ¯+â¯TCS. The results show that the growth of the films was linear, indicating the deposition of the same amount of material from the first bilayer without substrate interference. The release analysis showed slow kinetics, which occurred more rapidly for ERY LbL films, probably due to apparent activation energy, which were higher for films with TCS. The combination of TCS, ERY, and laser light (532â¯nm) for photodynamic inactivation of the fungus Candida albicans was analyzed, and the results were promising for future studies in applications, such as coating surfaces of dental implants.
Assuntos
Candida albicans/efeitos dos fármacos , Eritrosina/uso terapêutico , Fotoquimioterapia/métodos , Fármacos Fotossensibilizantes/uso terapêutico , Triclosan/uso terapêutico , Preparações de Ação Retardada , Relação Dose-Resposta a Droga , Eritrosina/administração & dosagem , Eritrosina/farmacocinética , Luz , Fármacos Fotossensibilizantes/administração & dosagem , Fármacos Fotossensibilizantes/farmacocinética , Triclosan/administração & dosagem , Triclosan/farmacocinéticaRESUMO
This work focuses on the preparation and characterization of nanoparticles containing triclosan. Additionally, in vitro percutaneous permeation of triclosan through pig ear skin was performed, and comparisons were made with two commercial formulations: An o/w emulsion and a solution, intended for the treatment of acne. The nanoparticle suspensions were prepared by the emulsification-diffusion by solvent displacement method, using Eudragit® E 100 as polymer. All batches showed a size smaller than 300 nm and a positive Zeta potential, high enough (20-40 mV) to ensure a good physical stability. Differential scanning calorimetry (DSC), transmission electron microscopy (TEM), and scanning electron microscopy (SEM) studies suggested that triclosan was molecularly dispersed in the nanoparticle batches containing up to 31% of triclosan, with good encapsulation efficiency (95.9%). The results of the in vitro permeation studies showed the following order for the permeability coefficients: Solution>cream≈nanoparticles; while for the amount retained in the skin, the order was as follows: cream>nanoparticles≈solution. Nanoparticles, being free of surfactants or other potentially irritant agents, can be a good option for the delivery of triclosan to the skin, representing a good alternative for the treatment of acne.