2.4.3. Nanoparticle Tracking Analysis

Nanoparticle tracking analysis (NTA) was conducted to determine the size, distribution, and concentration of nanoparticles in the developed formulations, providing a real-time concentration of nanoparticles (particles/mL) [24,25]. Measurements were performed using the NS300 equipment (NanoSight, Amesbury, UK), which was equipped with a 532 nm laser. The samples were diluted in deionized water (50,000×) and then transferred to a sample holder with a syringe. Data are expressed as the mean ± standard deviation, and measurements were performed in triplicate. Values for Span were calculated using Equation (2):

where D90, D50, and D10 are the average diameter of 90%, 50%, and 10% of the particle population, respectively.