Mesoporous silica core–shell composite functionalized with polyelectrolytes for drug delivery

•Mesoporous SiPs with high surface area were synthesized for drug delivery system.•The adsorbed amount of IBU is 1600 mg/g SiPs based on adsorption and TG method.•The 2D hexagonal structure of the SiPs and the fractal dimension were determined.•The IBU release is controllable by the formation of the core–shell structures.•The kinetic models well describe to release mechanism.

Porous, spherical (d ≈ 400 nm) polyelectrolytes-coated silica particles (SiPs) with high surface area (1254 m2/g) have been synthesized for controlled release of ibuprofen (IBU) in aqueous dispersion. The zeta potential of the SiPs was negative (−77 mV) at pH 5.5, so the shells, as a positively charged polyethylenimine (PEI) and a negatively charged poly(sodium-4-styrenesulfonate) (PSS) bind through electrostatic interactions. The adsorbed amount of IBU is 1666 mg/g and 1618 mg/g SiPs based on adsorption method in aqueous media and thermogravimetric (TG) measurement, respectively. The SiPs was characterized by using low temperature N2 adsorption/desorption method. The well-ordered structure of SiPs and the fractal dimensions of the core–shell composites were determined by small angle X-ray scattering (SAXS) measurement. Finally the release properties of the IBU have been investigated; kinetic models were used to describe the release mechanism. The results of this study highlighted that the SiPs and the core–shell particles are well applicable as dissolution-enhancing systems for encapsulation of poorly soluble drugs.

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