Experimental Design Modelling and Optimization of the Intercalation of Levofloxacin and Salicylic Acid into the Structure of ZnAl-LDH by Response Surface Method: in vitro Study of Release Kinetics, Antibacterial and Anti- Inflammatory Activities

In recent years, solid-state engineering has emerged as a promising method for improving the stability and potency of antibiotics and anti-inflammatory drugs. This study focuses on the design and optimization of the intercalation of levofloxacin (an antibiotic drug) and salicylic acid (an anti-inflammatory drug) into zinc-aluminium-layered double hydroxide galleries using response surface method. Release studies revealed that a burst release phenomenon was observed at the beginning of the release assay, and the pH value (in the range of 5.8-7.4) had very little influence on the levofloxacin and salicylic acid release efficiency. This indicates that zinc-aluminium-layered double hydroxide could be an effective inorganic carrier for levofloxacin and salicylic acid over a wide range of pH values. Four kinetic models were used to study the release kinetics and the drug release mechanism was also discussed. In addition, the intercalation of levofloxacin and salicylic acid into zinc-aluminium-layered double hydroxide exhibited enhanced antibacterial activity against Gram-positive Bacillus subtilis. The cell viability assay revealed non-toxic behavior of levofloxacin and salicylic acid intercalated into zinc-aluminium-layered double hydroxide against the monocyte/macrophage-like cell line.