Rare Earth-Modified Faujasites for Sustained Antibiotic Release: Insights Into Trimethoprim Delivery

The study explores the potential of zeolites as carriers for controlled trimethoprim (TMP) release. Zeolites of types X and Y were ion-exchanged with lanthanum (La³⁺) and cerium (Ce³⁺) ions and characterized to evaluate their efficacy in TMP sorption and delivery. Although type X zeolites were ineffective, type Y zeolites demonstrated significant TMP retention, with CeY adsorbing 0.95 mg (58%) and LaY adsorbing 0.78 mg (49%) of TMP per gram. Characterization techniques, including nitrogen adsorption/desorption, FT-IR, EDS, and SEM, confirmed TMP adsorption within the zeolite structure without altering its morphology. TMP release studies conducted in simulated body fluid (pH 7.4) and acidic conditions (pH 5) revealed sustained release profiles, with CeY outperforming LaY in both environments. The results highlight the potential of CeY and LaY zeolites as carriers for TMP, enabling controlled drug delivery while minimizing burst release. These findings offer a promising approach to improving antibiotic treatment and combating antibiotic resistance development.