Efficient co-delivery of immiscible hydrophilic/hydrophobic chemotherapeutics by lipid emulsions for improved treatment of cancer

Combinational nanomedicine is becoming a topic of much interest in cancer therapy, although its translation into the clinic remains extremely challenging. One of the main obstacles lies in the difficulty to efficiently co-deliver immiscible hydrophilic/hydrophobic drugs into tumor sites. The aim of this study was to develop co-loaded lipid emulsions (LEs) to co-deliver immiscible hydrophilic/hydrophobic drugs to improve cancer therapy and to explore the co-delivery abilities between co-loaded LEs and mixture formulation. Multiple oxaliplatin/irinotecan drug-phospholipid complexes (DPCs) were formulated. Co-loaded LEs were prepared using DPC technique to efficiently encapsulate both drugs. Co-loaded LEs exhibited uniform particle size distribution, desired stability and synchronous release profiles in both drugs. Co-loaded LEs demonstrated superior anti-tumor activity compared with the simple solution mixture and the mixture of single-loaded LEs. Furthermore, co-loaded nanocarriers could co-deliver both drugs into the same cells more efficiently and exhibited the optimized synergistic effect. These results indicate that co-loaded LEs could be a desired formulation for enhanced cancer therapy with potential application prospects. The comparison between co-loaded LEs and mixture formulation is significant for pharmaceutical designs aimed at co-delivery of multiple drugs.