pH-responsive LDH-palmitic acid nanohybrids for controlled drug delivery

Abstract An effective drug delivery system enhances bioavailability to improve therapeutic outcomes. Incomplete drug administration can reduce effectiveness, requiring higher or more frequent doses. This study focuses on developing nnanocomposites that use layered double hydroxides (LDHs) as drug carriers to improve bioavailability. Zinc-aluminium (ZnAl-LDH) and calcium-aluminium (CaAl-LDH) LDHs were synthesised, and palmitic acid (PA) was intercalated into these structures using the co-precipitation method, forming ZnAl-LDH-PA and CaAl-LDH-PA nanocomposites. PXRD analysis confirmed successful intercalation, with increased interlayer spacing from 8.60 Å to 15.21 Å for 0.05 M CaAl-LDH-PA and from 8.92 Å to 14.35 Å for 0.2 M ZnAl-LDH-PA. FTIR spectroscopy further validated PA incorporation by showing the absence of nitrate peaks at 1347 cm −1 and the presence of asymmetrical and symmetrical COOˉ stretching vibrations in the 1540 to 1577 cm −1 range. Controlled release studies in simulated physiological media showed pH-responsive behaviour: CaAl-LDH-PA achieved sustained release of 75 % at pH 4.8, whereas ZnAl-LDH-PA displayed prolonged release at pH 7.4 (62 %). These findings demonstrate the potential of ZnAl- and CaAl-LDH nanohybrids as effective pH-responsive carriers for enhanced bioavailability.