Optimized hydration dynamics in mucoadhesive xanthan-based trilayer vaginal films for the controlled release of tenofovir

Karaya gum, pectin and xanthan gum have been tested as candidates for manufacturing mucoadhesive trilayer films containing ethylcellulose and chitosan for the vaginal administration of the antiviral Tenofovir (TFV). The swelling profile correlated with the amount of mobile dipoles determined by impedance spectroscopy allows the determination of the hydration dynamics of these films. The fast water penetration has been demonstrated to favor the formation of polyelectrolyte complexes (PEC) via hydrogen or ionic bonds which would favor a controlled release. The incorporation of an inorganic drug release regulator induces the weakness of the polymeric chains thus enhancing the ionic mobility via the formation of low molecular weight PECs in films manufactured with karaya gum. Due to the different mechanical properties of the individual components, pectinbased films failed for a potential pharmaceutical formulation. However, mucoadhesive trilayer films produced with xanthan gum have demonstrated a moderate swelling, improved wettability and a controlled release of TFV.

Automated summary

Karaya gum, pectin, and xanthan gum were tested as candidates for manufacturing mucoadhesive trilayer films for vaginal administration of the antiviral Tenofovir (TFV). The swelling profile of the films was determined by impedance spectroscopy, and it was found that fast water penetration facilitated the formation of polyelectrolyte complexes (PEC) and controlled release. The incorporation of an inorganic drug release regulator weakened the polymeric chains, enhancing the ionic mobility and forming low molecular weight PECs in films made with karaya gum. Pectin-based films were not suitable for pharmaceutical formulation due to their different mechanical properties. However, mucoadhesive trilayer films produced with xanthan gum showed moderate swelling, improved wettability, and a controlled release of TFV.