Phosal® Curcumin-Loaded Nanoemulsions: Effect of Surfactant Concentration on Critical Physicochemical Properties

Curcumin is a well-known and widely used substance of natural origin. It has also been found to be helpful in the treatment of liver diseases. Unfortunately, curcumin has very low bioavailability and a sensitivity to external agents. Improving these parameters is the subject of many studies. One way to overcome these problems may be to use Phosal® Curcumin as a source of curcumin and encapsulate this dispersion into a nanoemulsion using different types and concentrations of surfactants and co-surfactants, thus manipulating the physicochemical parameters of the nanoemulsion. The present study aimed to develop curcumin-loaded nanoemulsions for intravenous administration and to investigate the effect of Kolliphor HS15 concentration on their critical quality attributes. Methods: Phosal® Curcumin-loaded nanoemulsions with different concentrations of Kolliphor HS15 were prepared by high-pressure homogenization. The effect of Kolliphor HS15 on emulsion physicochemical properties such as mean droplet diameter (MDD), polydispersity index (PDI), zeta potential (ZP), osmolality (OSM), and pH, as well as encapsulation efficiency (EE) and retention rate (RR) of curcumin, were determined. Mid-term stability studies and short-term stress tests were conducted to evaluate the impact of Kolliphor HS15 on the critical quality attributes of the curcumin-loaded nanoemulsions stored under various conditions. Results: Five nanoemulsions with increasing Kolliphor HS15 concentrations were developed. Their MDD ranged from 85.2 ± 2.0 to 154.5 ± 5.1 nm, with a PDI from 0.18 ± 0.04 to 0.10 ± 0.01 and ZP from −15.6 ± 0.7 to −27.6 ± 3.4 mV. Depending on the concentration of Kolliphor HS15, the EE ranged from 58.42 ± 1.27 to 44.98 ± 0.97%. Conclusions: The studied parameters of the developed nanoemulsions meet the requirements for formulations for intravenous administration. Using the appropriate concentration of Kolliphor HS15 allows for a formulation that presents a protective effect against both curcumin and emulsion degradation.