Selective COX-2 Inhibitor Etoricoxib's Liposomal Formulation Attenuates M2 Polarization of TAMs and Enhances its Anti-metastatic Potential.

Introduction: COX-2 inhibition in pro-tumoral M2 polarization of Tumor-Associated Macrophages (TAMs) underscore the improved prognosis and response to cancer therapy. Thus, etoricoxib, a COX-2 inhibiting NSAID drug is highly effective against tumorigenesis, but its compromised solubility and associated hepatotoxicity, and cardiotoxicity limit its clinical translation.

Objective: In view of the consequences, the proposed study entails the development of a liposomal formulation for etoricoxib and evaluates its anticancer potential.

Methods And Result: Etoricoxib loaded liposome was prepared by thin layer hydration method and characterized as a nearly monodisperse system with particle size (91.64 nm), zeta potential (-44.5 mV), drug loading (17.22%), and entrapment efficiency (94.76%). The developed formulation was administered subcutaneously into the orthotopic 4T1/Balb/c mice model. Its treatment significantly reduced tumor size and skewed M2 polarization of TAMs to a greater extent against free etoricoxib. Furthermore, Tumor tissues analyzed through immunoblotting study confirmed the reduction in Akt phosphorylation at Thr308 residue and pro-tumoral VEGF, MMP-9, and MMP-2 proteins; Moreover, histology studies and microCT analysis of bones revealed the enhanced anti-metastatic potential of etoricoxib delivered through developed formulation against free etoricoxib.

Conclusion: As an epilogue, the developed formulation efficiently delivers poorly soluble etoricoxib, enhances its therapeutic potential as an anti-tumor and anti-metastatic agent, and directs explorative research for clinical translation.