DEVELOPMENT AND IN VITRO EVALUATION OF MULTILAMELLAR LIPOSOMES OF LEVOFLOXACIN AGAINST MYCOBACTERIUM TUBERCULOSIS

Tuberculosis (TB), caused by Mycobacterium tuberculosis, remains one of the main global public health challenges, worsened by the emergence of strains resistant to conventional treatments. Levofloxacin (LEVO), a fluoroquinolone antibiotic, is an alternative for treating resistant forms of TB. However, it has limitations such as low solubility, plasma half-life, and adverse effects. Thus, the development of nanostructured systems such as multilamellar liposomes emerges as an alternative to improve the therapeutic efficacy of antibiotics. Therefore, this study aimed to produce multilamellar liposomes containing LEVO and evaluate their in vitro antimycobacterial activity. Liposomes were prepared according to Beaumont et al. (2021) by mixing soy phosphatidylcholine (Lipoid S-100), Tween 80, and LEVO at a concentration of 1 mg/mL. The formulations were evaluated for mean diameter (Z-Ave) and zeta potential (ZP) by DLS. In vitro antimycobacterial activity was determined against the drug-susceptible Mtb strain H37Ra by plate microdilution, using resazurin as the indicator solution. The liposomes showed a Z-Ave distribution above 500 nm, with ZP greater than -5 mV, indicating colloidal stability. The MIC of the formulation containing LEVO was 0.031 µg/mL against the H37Ra strain, while free LEVO showed an MIC of 0.5 µg/mL. The liposomal levofloxacin formulation demonstrated stability and in vitro antimycobacterial activity superior to the free drug. These results reinforce its potential as a promising candidate for continued testing, aiming at its application in tuberculosis treatment.