The present invention is directed to multiple a-lipoic acid-containing hydrophobic compounds (mALAs) capable of acting as scavengers of free radicals, metals and reactive oxygen species (ROS). Methods of synthesizing novel antioxidant mALAs, spontaneous emulsification or nanoprecipitaion thereof to produce antioxidant nanospheres and their use in preventing or treating diseases or conditions caused by oxidative stress and other free radical mediated conditions are also described. Another aspect of this invention is the use of these antioxidant nanospheres for the preparation of antioxidant particulate delivery system of therapeutic agents.