Assessment of the technological properties of idebenone and tocopheryl acetate co-loaded lipid nanoparticles

Abstract

Several liquid lipids have been proposed to obtain nanostructured lipid carriers (NLC) with improved efficiency. An attractive strategy is the use of oils that could elicit a synergic effect with the loaded drug. In this work, different percentages (0–4% w/w) of tocopheryl acetate (TA), an oily antioxidant, were used as liquid lipid to prepare NLC loading idebenone (IDE), a synthetic antioxidant investigated for the treatment of neurodegenerative and topical diseases. The technological properties of such NLC were evaluated, as well as the interactions among lipid core components. Loading different percentages of IDE (1–4% w/w) into NLC containing TA up to 4% w/w, no significant change of mean size and polydispersity index was observed. IDE loading capacity was 4% w/w but NLC containing IDE percentages greater than 1.5% w/w showed poor stability during long-term storage. Differential scanning calorimetry analyses highlighted linear relationships between peak temperature and TA percentages, while the enthalpy variation and recrystallization index values showed that increasing the percentage of TA led to less crystalline structure of the NLC core. Therefore, NLC co-loading IDE and TA could be useful to design new delivery systems for the treatment of diseases that could benefit from the co-administration of these antioxidants.