Electrosprayed hydrophilic nanocomposites coated with shellac for colon-specific delayed drug delivery

Abstract Advanced medicated nanomaterials that provide time- and target-specific drug release profiles are highly desired for efficacious drug delivery. In this study, a structural nanocomposite (P2) consisted of tamoxifen citrate (TC) and polyvinylpyrrolidone (PVP) (2:8, w:w) as core and shellac as shell was designed and fabricated using a modified coaxial electrospraying process. Shellac solution, which could not be converted into solid particles individually, was explored as a shell working fluid to encapsulate the core TC-PVP blending solution, which could be electrosprayed into solid particles (P1) all alone. SEM and TEM evaluations demonstrated that the quality of the core-shell particles P2 was higher than that of the monolithic particles P1 in terms of particle diameter, size distribution and number of satellites. XRD results suggested that TC was similarly present in an amorphous state in particles P1 and P2 due to its fine compatibility with PVP, which was verified through FTIR tests. In vitro dissolution experiments suggested that P2 could provide the designed drug colon-specific delayed release characteristics, passing through acidic conditions of pH 2.0 dissolution media and freeing all of the loaded TC within 5 min at pH 7.4 dissolution media.