Nanostructured Lipid Carrier Based on Melaleuca Alternifolia and Bacuri Butter Associated with the Subdose of Amphotericin B: Cytotoxic and Antimicrobial Activity

Therefore, the purpose of this study was to develop a nanostructured lipid carrier (NLC) based on Melaleuca alternifolia and bacuri vegetable butter associated with a subdose of amphotericin B (AmB) and to investigate its physicochemical characteristics, stability, antimicrobial activity and cytotoxicity, with a view to patenting and transition to clinical trials. After obtaining the NLC, the particle size (PS), polydispersity index (PDI), zeta potential (ZP), dosage, encapsulation efficiency (EE%), pH, spread ability, texture, stability, antimicrobial activity and cell viability were analyzed using the MTT method. NLC showed a TP of 177.5 nm, PDI of 0.176 and PZ of -29.3 mV. The encapsulation efficiency was ~ 99.9%, with a pH of 5.83 and pre- and post-freeze–thaw spread ability indices of 0.49 and 0.37, respectively. The formulation showed a firmness of 966.5, consistency of 1698.1, cohesiveness of 594.4 and viscosity index of 3039.9. The NLC containing AmB exhibited an inhibitory effect against S. aureus and E. coli, as well as an inhibitory and dispersing effect against C. albicans. It also showed no cytotoxicity in mouse fibroblast cell lines. In summary, it can be concluded that NLC shows physical and chemical stability, antibacterial inhibitory potential and antifungal dispersion activity. In addition, the subdose of AmB proved to be safe in terms of cytotoxicity.