Influence of the Nanocomposite MgAl-HTlc on Gastric Absorption of Drugs: In Vitro and Ex Vivo Studies

Furosemide (FURO) is a BCS class IV drug preferentially absorbed in the gastric environment. A previous study demonstrated that its intercalation into the lamellar inorganic matrix MgAl-HTlc, giving rise to MgAl-HTlc-FURO, improves its dissolution in acidic medium. As the gastric absorption of drugs can be hindered from the biological barriers mucus and gastric mucosa, the purpose of this work was to evaluate the effect of MgAl-HTlc on gastric pH, the possible modifications induced on mucus rheology and the influence on both artificial and biological membranes. Firstly the effect of growing MgAl-HTlc concentrations on gastric pH was evaluated. Both drug flux across the mucus layer and permeability across an artificial and biological membrane (gastric mucosa) have been studied as well. The results highlighted that drug flux across gastric mucus is improved in presence of MgAl-HTlc-FURO and that MgAl-HTlc is able to modify mucus structure in a reversible manner. From permeability studies emerged that the use of a biological membrane is the most suitable for such studies and that MgAl-HTlc-FURO enhances FURO Papp. Data obtained suggest that MgAl-HTlc is a suitable material able to improve the biopharmaceutical properties of class IV BCS drugs.