This invention provides a soluble nano-sized particles formed of a core (water-insoluble lipophilic compound or hydrophilic compound) and an amphiphilic polymer and which demonstrated improved solubility and/or stability. The lipophilic compound within the soluble nano-sized soluble ("solu-nanoparticles") may consist of pharmaceutical compounds, food additives, cosmetics, agricultural products and veterinary products. The invention also provides novel methods for preparing the nano-sized soluble particles, as well as a novel chemical reactor for manufacturing an inclusion complex comprising the nano-sized soluble particles.