Nanonization of Insulin from Dimethylsulfoxide Solution Using Supercritical Carbon Dioxide as an Antisolvent

Insulin was precipitated from solution in dimethylsulfoxide using supercritical carbon dioxide as an antisolvent. Solution enhanced dispersion by supercritical fluids (SEDS) process was applied to produce nano‐size insulin particles. We used dimethylsulfoxide to help the supercritical carbon dioxide to extract water from the aqueous protein solution. Various sizes of insulin nano‐particles were successfully prepared with a narrow particle size distribution from aqueous dimethylsulfoxide solution without using any additive. The theoretical particle sizes were deduced from the calculated droplet sizes based on a modified Jasuja's equation. The calculated mean particle sizes and the experimentally obtained ones were compared and the results showed an excellent correlation coefficient (R2) of 0.9738.