Immediate release of helicid from nanoparticles produced by modified coaxial electrospraying

In this paper, a modified coaxial electrospraying process was explored for the generation of novel nanoscale composite materials. A solution comprising 5% (w/v) of the model drug helicid and 10% (w/v) polyvinylpyrrolidone (PVP) K10 in a mixture of N,N-dimethylacetamide and ethanol (4:6, v:v) was employed as the shell working liquid. This could not be processed into a solid product when processed by single-fluid electrospraying. However, when undertaking co-axial electrospraying with a core shellac solution (40% w/v in ethanol) solid particles were obtained. An extremely thin nanocoating layer of drug-polymer composite with an estimated thickness of 7 nm was deposited on a shellac core. X-ray diffraction and infrared spectroscopy demonstrated that the drug was converted into an amorphous nanocomposite with the PVP in the shell layer, losing its original crystalline state. In vitro dissolution tests revealed that all the helicid loading could be released within one minute, suggesting the particles have potential applications to deliver very rapid therapeutic effects. Mechanisms are proposed underlying the formation and functional performance of the materials.