Fabrication and characterization of apremilast-loaded zinc oxide-mesoporous silica nanoparticles for psoriasis treatment

<b>Aim:</b> The study was aimed to formulate and evaluate apremilast-loaded zinc oxide-mesoporous silica nanoparticles for treatment of psoriasis. <b>Materials &amp; methods:</b> Mesoporous silica nanoparticles were prepared by using sol-gel method and evaluated for particle size, <i>in vitro</i> drug release, <i>in vitro</i> cytotoxicity study and <i>in vivo</i> pharmacodynamic study. <b>Results:</b> The synthesized mesoporous silica nanoparticles showed particle size of 319.9 ± 3.9 nm, with 24 ± 0.217% of loading capacity. <i>In vitro</i> cytotoxicity study on A-431 cell line showed increased anti-psoriatic activity of apremilast-loaded zinc oxide-mesoporous silica nanoparticles. <i>In vivo</i> pharmacodynamic study and histological studies showed improved efficacy of drug in imiquimod-induced psoriasis mice model. <b>Conclusion:</b> The apremilast-loaded zinc oxide-mesoporous silica nanoparticles showed improved therapeutic efficacy, suggesting that they are promising approach for topical treatment of psoriasis. Mesoporous silica nanoparticles (MSNs) were successfully prepared by the sol gel method. The structural characterization of MSNs was confirmed by the BET analysis and TEM analysis confirmed the uniform spherical formation of the MSNs. Zinc oxide was used as anti-inflammatory agent, antibacterial agent and has high biocompatibility. It absorbs the UV rays which is used in the phototherapy for the reduction of inflammation in the psoriasis. The amino functionalization of MSNs was performed to enhance the physical and chemical properties of the MSNs, and it was found that drug loading of apremilast was enhanced, it prevented leakage of drug and prevented aggregation of the particles. The zeta analysis and ninhydrin test confirmed the amino functionalization on MSNs. The <i>in vitro</i> and <i>ex vivo</i> drug-release study showed that sustained drug release was obtained in ZnO-MSNs. The cell viability studies showed enhanced efficacy of apremilast when loaded in the ZnO-MSNs. MSNs improved efficacy of apremilast in <i>in vivo</i>, imiquimod-induced psoriasis model, as the particle size of around 300 nm retained on the skin and sustained the drug release to elicit the action of drug.