Nano-delivery systems based on carvacrol prodrugs and fibrous clays

The fibrous silicates, Palygorskite and Sepiolite, were investigated as low-cost nanocarriers for three carvacrol prodrugs to ameliorate their pharmacokinetic and biopharmaceutic profiles. Adsorption equilibrium studies were performed in order to obtain a drug-clay hybrid system. These hybrid systems were characterized by thermal analysis, X-ray diffraction, and Fourier transform infrared spectroscopy, to study the degree and kind of interactions between the organic and inorganic components. In vitro release and chemical stability of prodrug-clay hybrids were studied in physiological gastrointestinal simulated fluids. The results showed an improvement of the chemical stability of prodrugs in hybrids systems, as well as a sustained release and a retained bioconversion of the prodrugs into the pharmacologically active carvacrol, to improve the antimicrobial activity.