Nanoparticle Production of Zingiber officinale Roscoe Rhizome Extracts by ESS (expansion of supercritical solution)

Abstract

To propose a modified RESS method of herbal pharmaceutical extracts nanoparticle production. A vast number of methods have been applied to water-insoluble pharmaceuticals to improve their solubility. Nanoparticle production of pharmaceuticals is considered as one of the high-speed ways to improve solubility. Supercritical CO2 was applied to extract Zingiber officinale Roscoe rhizome pharmaceutical. Then a modified RESS (rapid expansion of supercritical solution) method, called ESS (expansion of supercritical solution), was exerted to obtain NPs (nanoparticles) of the extracted pharmaceuticals. Initially, applying high pressure in supercritical CO2 contributed to the extract dissolution such that supercritical CO2 was saturated with the sample. Then by decreasing the pressure, an expansion occurred in the saturated medium. This expansion reduced the power of supercritical CO2 solvent and induced the sample nanoparticle nucleation in the needle valve. Unlike rapid expansion of supercritical solution methodology, in this technique, the initial and secondary pressures were permanently above the critical pressure to provide a gentle expansion, which contributes to the production of uniform and small particles. The obtained uniform NPs had a narrow size distribution. Consequently, ESS technique can be considered as an efficient technique for improving the solubility of hydrophobic pharmaceuticals such as [6]-gingerol.