Synthesis of Thiomer/Nanoclay Nanocomposites as a Potential Drug Carrier: Evaluation of Mucoadhesive and Controlled Release Properties.

Novel thiomer/nanoclay nanocomposites based on a thiomer and montmorillonite (MMT) were prepared in order to obtain a mucoadhesive material with controlled release properties for its potential use as drug carrier. The thiomer was synthesized by immobilization of L-cysteine in alginate mediated by carbodiimide reaction and further characterized by FT-IR and Ellman's reaction. Nanocomposites with growing concentrations of thiomer and MMT were prepared and analyzed by XRD, TGA and TEM. Rheological behavior of nanocomposite in contact with mucin and intestinal mucus were studied as in vitro and in situ mucoadhesion approach, showing until ∼10-fold increasing in the complex viscosity and ∼27-fold in elastic modulus when the amount of thiomer is increased. Higuchi and Korsmeyer-Peppas kinetic models were evaluated in order to study the release of deltamethrin from nanocomposite films. Release profiles showed a retard in the migration of the drug influenced by the amount of MMT (P < 0.05). Diffusion coefficient (D) showed a significant decrease (P < 0.0001) when concentration of MMT is increased reaching D = 4.18 × 10^-7 m² h^-1, which resulted ∼7-fold lower in comparison with formulation without MMT. This hybrid nanocomposite can be projected as a potential mucoadhesive drug carrier with controlled release properties.