Novel Spontaneous Nanoemulsions for Phosphorus Selenide Compounds: Toward Enhanced Solubility and Stable Aqueous...

Organoselenium compounds have been extensively studied for their potential anticancer, hypoglycemic, antimicrobial, antioxidant, and anti-inflammatory properties. However, these compounds are highly lipophilic, restricts their solubility in organic solvents and limits their administration routes. Investigating surfactant interaction with organoselenium compounds offers opportunities to enhance formulation efficacy by increasing their bioavailability and water solubility through the formation of stable colloidal systems. In this study, phosphorus selenide compounds were mixed with three commonly used surfactants: cetyltrimethylammonium bromide (CTAB), sodium dodecyl sulfate (SDS), and Tween 20 (polysorbate 20). The resulting colloidal structures were characterized by ultraviolet-visible (UV-vis) spectroscopy, dynamic light scattering (DLS), ζ-potential (ZP), Fourier transform infrared (FTIR) spectroscopy, nuclear magnetic resonance (NMR) spectroscopy, and atomic force microscopy (AFM). Improved apparent solubility was observed for all compounds, with aliphatic phosphorus selenide compounds exhibiting greater compatibility with the surfactants than aromatic variants. Formulations with SDS and CTAB were more stable than those with Tween 20, likely due to unfavorable electrostatic interactions between the nonionic surfactant and the phosphorus selenide compounds. Particle sizes ranging from 100 to 250 nm were measured and, together with conductivity and AFM analyses, indicated the formation of spontaneous nanoemulsions. Studying surfactant interactions with these compounds may improve formulations by reducing the required amount of active compound required, enabling more precise release. This approach also reduces reliance on organic solvents, thereby minimizing environmental impact and offering promising applications in diverse fields, including pharmaceuticals, pesticide formulations, and catalysis.