Background: Caffeic acid (CA), with antioxidant and immunomodulatory properties, was formulated in liposomes to increase its efficacy. The study targets triple-negative breast cancer (TNBC), characterized by the absence of ER, PR, and HER2 receptors. Methods: For CA-loaded liposomes, the pharmacological effects on TNBC cell lines, parental Hs578T (HS) and Doxorubicin-resistant Hs578T (HSD) cells were evaluated by determining the cell growth inhibition ratio measured by the (3-[4,5-dimethylthiazo