Studies on the stability and kinetics of drug release of dexamethasone phosphate intercalated layered double hydroxides nanohybrids

• Stabilization and release of dexamethasone phosphate.
• XRD confirmed the intercalation.
• Release study shows sustain release behaviour for nanohybrids.
• Release is due to combined effect of dissolution and inter-particle diffusion.

We report the intercalation of dexamethasone sodium phosphate drug in Mg/Al layered double hydroxides (LDHs) through co-precipitation technique. The as-synthesized nanohybrid was characterized by XRD, FTIR and thermal analysis techniques, which reveal that the dexamethasone phosphate anions are accommodated within the brucite layers. The shifting in the stretching frequency of phosphate anion of the drug provides strong evidence that the drugs are bonded to LDHs through electrostatic force. The surface charge analysis suggested the possibility of charge manipulation in LDHs system by varying intercalated anions. In-vitro release study of as-synthesized nanohybrid particles suggests a significant reduction in release rate of dexamethasone phosphate anions from Mg/Al–Dexa LDHs and is due to confinement of drugs in the interlayer. The mechanism of drugs diffusion in nanohybrid is studied by using dissolution–diffusion kinetic model, which reveals that it is probably due to dissolution and intra-particle diffusion of anions in the physiological medium.

New dexamethasone phosphate-LDHs (Mg/Al–Dexa) nanohybrid materials having single polymorphic form of drugs exhibit hydrophilic behaviour in buffer (pH 7.4) and the kinetics of drug release involves the dissolution and intra-particle diffusion process.Figure optionsDownload as PowerPoint slide