We report our findings on the impact of the glass composition on the corrosion of microparticles occurring during the preparation of glass-ceramics using the direct doping method. Microparticles (MPs) with the composition Sr₄Al₁₄O₂₅:Eu²⁺,Dy³⁺ with blue-green persistent luminescence were chosen as the changes in their spectroscopic properties can be related to the MPs’ corrosion. The MPs were added in phosphate-based glasses with different compositions. When using the same doping parameters, the glass system with the composition 90NaPO₃-10Na₂O (mol%) was found to be the least corrosive on the MPs whereas the glass system with the composition 90NaPO₃-10NaF (mol%) is the most corrosive on the MPs probably due to their different viscosity at 575 °C, the temperature at which the MPs are added in the glass melts.