C 60 and C 70 solubility in a stable excipient for drug delivery

Fullerenes are lipophilic. Thus, vegetable oils or synthetic esters like ethyl oleate have been used as vehicles for both C60 and C70 fullerenes for in vitro and in vivo experimentation for instance in the inhibition of tumour growth and as anti-inflammatory drugs. The problem with these excipients is their sensitivity to autoxidation which is transferred to the fullerene solutes and the presence of other undesired components and by-products. It is shown that medium chain triglycerides (MCT) is an ideal vehicle for both C60 and C70 drug delivery since MCT are fully saturated and resistant to autoxidation. The solubility of C60 and C70 in MCT estimated through the Van Krevelen and the more sophisticated Hansen models predict just a border line solubility. Instead, it was experimentally found that C60 reaches a concentration of 210 mg/ml in MCT and C70 a concentration of 98 mg/L. This discovery paves the way to a new, effective, stable solutions to delivery fullerenes in vitro and in vivo, per os and through injection, without the drawbacks faced with any other lipophilic excipient tested till now. The MCT thermal behaviour was studied with DSC and its polarity evaluated through the Reichard’s ET(30) scale and also through the Nile Red polarity scale E(NR).