Rheological mucoadhesion and cytotoxicity of montmorillonite clay mineral/hybrid microparticles biocomposite

A biocomposite based on montmorillonite clay mineral (MMT) and hybrid biopolymer microparticles (MP) carrying atorvastatin (AC), these were designed for oral drug carrier was characterized by scanning and transmission electron microscopy (SEM &TEM), differential scanning calorimetry (DSC) and in vitro biocompatibility by cell viability on fibroblast cells. The rheological synergism relation (by linear oscillatory tests at different pH and frequency) with the mucoadhesive properties revealed interactions between isolated mucin and the MP/MMT biocomposite and those between the mucin and the individual components. Results of these tests showed that the MP/MMT biocomposite provides an improvement in the thermal stability and hence good biocompatibility exhibiting anti-proliferation effects at high concentrations. To our knowledge, no previous reports exist on the determination of the rheological synergism in biocomposites with MMT clay either alone. Moreover, we found a dependence of the rheological synergism on pH and frequency provided by linear viscoelastic data at low frequencies. The MP/MMT biocomposite possesses the highest rheological synergism related to the strongest interaction with mucin at pH 1.6. [Display omitted] •A raspberry-like structure with MMT adsorbed on the MP surface was observed•MP/MMT composite exhibited improved thermal stability•The composite showed good biocompatibility due to high cell bioavailability•Strong pH-dependence of the interaction between mucin and MP/MMT composite was observed by rheological measurements•Solid-like confirmation is proposed to avoid false-negative rheological mucoadhesive assessment