The Formation of β-Cyclodextrin Complexes with Levofloxacin and Ceftriaxone as an Approach to the Regulation of Drugs’ Pharmacokinetic

Levofloxacin-Fatty Acid Systems: Dual Enhancement Through Deep Eutectic Formation and Solubilization for Pharmaceutical Potential and Antibacterial Activity

Fatty acids, including medium-chain saturated and polyunsaturated fatty acids, are known for their broad health benefits, including antimicrobial activity. Through their green properties, deep eutectic systems have been heralded as having the potential to be at the forefront of pharmaceutical applications. In this work, capric acid and geranic acid, two examples of medium-chain saturated and polyunsaturated fatty acids, were employed to enhance the pharmaceutical properties and the antibacterial activity of levofloxacin. To this end, levofloxacin formulations with either capric or geranic acid were prepared and characterized using appropriate techniques. Levofloxacin was utilized to create innovative deep eutectic systems in conjunction with capric acid at three different molar ratios: 1:9, 2:8 and 3:7. This was confirmed through a rigorous analysis involving nuclear magnetic resonance, infrared spectroscopy and differential scanning calorimetry. Furthermore, it is noteworthy that geranic acid demonstrated an impressive threefold improvement in levofloxacin's solubility compared to its solubility in aqueous solutions. The antibacterial activity of the novel combinations of levofloxacin with either fatty acid was evaluated using a checkerboard titration assay. Gratifyingly, both formulations exhibited synergistic effects against a panel of levofloxacin-sensitive and resistant Gram-negative bacteria. In conclusion, the observed superior antibacterial activity of levofloxacin illuminates the potential use of fatty acid-based formulations and deep eutectic systems as green and innovative strategies to combat the global antimicrobial resistance problem.

Cyclodextrins and Their Polymers Affect Human Serum Albumin's Interaction with Drugs Used in the Treatment of Pulmonary Infections

Respiratory infectious diseases have challenged medical communities and researchers. Ceftriaxone, meropenem and levofloxacin are widely used for bacterial infection treatment, although they possess severe side effects. To overcome this, we propose cyclodextrin (CD) and CD-based polymers as a drug delivery system for the drugs under consideration. CD polymers demonstrate higher binding affinity for levofloxacin (Ka ≈ 10⁵ M) compared to drug-CD complexes. CDs slightly alter the drugs' affinity for human serum albumin (HSA), whereas CD polymers increase the drugs' binding affinity up to 100 times. The most significant effect was observed for more the hydrophilic drugs ceftriaxone and meropenem. The drug's encapsulation in CD carriers leads to a decrease in the degree of change in the protein's secondary structure. The drug-CD carrier-HSA complexes demonstrate satisfying antibacterial activity in vitro, and even a high binding affinity does not decrease the drug's microbiological properties after 24 h. The proposed carriers are promising for a drug form with a prolonged drug release.