Objective: Doxorubicin (DOX), one of the most effective anticancer drugs frequently is used in breast cancer treatment. However, its clinical use is restricted by toxicity to normal cells and its low specificity against cancer cells. As an alternative, nanoparticle drug delivery systems such as Solid Lipid nanoparticles (SLN) is used to overcome these limitations in cancer therapy. This work is intended to develop and evaluate a SLN system that can efficiently load and release DOX and enhance its efficacy against MDA-MB-231 cancer cell line. Materials and Methods: The SLN drug delivery system has been prepared by a new strategy based on microemulsion system. Particle size and zeta potential were evaluated using dynamic light scattering (DLS), and drug release rate from the system was investigated in vivo and in vitro. Safety of the DDS and its gradient was checked using bone marrow mesenchymal stem cells (BMSCs) and red blood cells (RBC). MDA-MB-231 cell line was used to check the DDS+ DXR and CXR only. Results: The particle size was reported to be approximately 145 nm and its poly dispersity index (PDI) was 0.238. It was observed that the system and its components are completely nontoxic. In addition, the drug loading rate was 93% and the releasing percentage of the drug after 24 h through mouse skin and dialysis membrane was obtained as 38 and 56 %, respectively. The half maximal inhibition concentration (IC50) of the drug for 48 and 72 hours of treatment was calculated to be 1.19 and 0.94 μM respectively. Conclusion: Safeness, drug carrier capacity and its releasing rate of the newly developed SLN showed that this system is a suitable carrier for doxorubicin.
