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Zeta potential is an essential characteristic of particles that can be easily calculated with a zetasizer tool [92]. It is an important aspect to understand particle stability. In drug delivery applications, the particle charge is an important factor. “Zeta potential is the potential differentiation between the surface and the stationary fluid layer connected to the dispersed sample.” The particle surface is surrounded by ions charged opposite to each other, which generates the thin stern layer adsorbing non-hydrated co-ions and counter ions at the surface. The next layer consists of the hydrated/partially hydrated counter ions, and the last layer consists of co-ions; this layer is known as the diffuse layer. This layer is attached to the slip plane, an imaginary plane that separates mobile ions from immovable ions on the surface. A stable dispersion has zeta potential ideally from -30 to +30 mV. Repulsion occurs between particles with a strong positive or negative surface charge; it results in reduced stability span of dispersion through flocculation or aggregation by particles [107]. The pH of the dispersion is the factor that mostly affects the zeta potential [108].