Mixed micelles made of poly(ethylene glycol)-phosphatidylethanolamine conjugate and d-α-tocopheryl polyethylene glycol 1000 succinate as pharmaceutical nanocarriers for camptothecin

Micelles from the mixture of poly(ethylene glycol)-phosphatidyl ethanolamine conjugate (PEG-PE) and d-α-tocopheryl polyetheyene glycol 1000 succinate (TPGS) were prepared loaded with the poorly soluble anticancer drug camptothecin (CPT). The solubilization of CPT by the mixed micelles was more efficient than with earlier described micelles made of PEG-PE alone. CPT-loaded mixed micelles were stable upon storage and dilution and firmly retained the incorporated drug. The cytotoxicity of the CPT-loaded mixed micelles against various cancer cells in vitro was remarkably higher than that of the free drug. PEG-PE/TPGS mixed micelles may serve as pharmaceutical nanocarriers with improved solubilization capacity for poorly soluble drugs.