Mesoporous silica nanoparticles have emerged as promising nanodelivery systems due to their ability to incorporate small molecules as well as biomacromolecules. Their preparation is simple, reproducible, cost-effective, and well-known. By coating a magnetic nanoparticle core with a mesoporous silica shell, the combined benefits of magnetic nanoparticles and mesoporous silica nanoparticles can be harnessed. This study aimed to develop a method for loading a poorly soluble model drug (ibuprofen) into the mesoporous silica coating of magnetic nanoparticles and to couple the drug loading with subsequent drying of the dispersion using the electrospinning method. The drug loading process was based on the drug adsorption from solution. During the development and optimization of the procedure, various parameters affecting drug loading and the electrospinning drying method were investigated. The primary building block of the nanofibers was hydrophilic polyethylene oxide, supplemented with poloxamer 188 to enhance nanofiber dissolution and stabilize the reconstituted magnetic nanoparticle dispersion. The prepared electrospun products were characterized regarding their morphology, magnetic nanoparticle and drug content, disintegration, potential chemical interactions between the components, nanoparticle size after reconstitution and drug release. The drug loading method was based on the incubation of magnetic nanoparticles in ibuprofen solution, employing ultrasound followed by overnight shaking. After the drug loading, the magnetic nanoparticles were magnetically separated from the ethanol solution with excess of ibuprofen and redispersed in an acidic polymer solution using a vortex mixer and sonication. Electrospinning of the prepared dispersion of ibuprofen-loaded magnetic nanoparticles enabled the formation of a solid, non-powder product, from which magnetic nanoparticles can be easily and rapidly reconstituted. The optimized procedure was tested on two types of magnetic nanoparticles with mesoporous silica coating with different pore sizes, demonstrating correlation between the ibuprofen loading and the capacity of pores in the silica coating of magnetic nanoparticles. The prepared nanofibers contained ~20% (w/w) of magnetic nanoparticles, which were loaded with up to ~20% (w/w) of ibuprofen. We have thus prepared a solid non-powder formulation with magnetic nanoparticles and loaded drug, which enables rapid and simple reconstitution of the ibuprofen-loaded nanoparticles just prior potential parenteral application.
|
