Lithopone’s historical significance is further accentuated by the advancements and modifications that followed its inception. The 1874 patent by J.B. Orr, for instance, ushered in a new white pigment—Orr’s Zinc White. This innovation was attained by co-precipitating zinc sulfate and barium sulfide, followed by a calcination process. Further refinements marked the subsequent decades, the most notable being the enhancement of lightfastness achieved in the 1920s by introducing small amounts of cobalt salts before calcination.

Fig. 3. Cell survival measured on samples of MSSA with bare and functionalized P25TiO₂NPs after 6 h of irradiation. A: P25TiO₂NPs, B:vitaminB2@P25TiO₂NPs, C: vitaminC@P25TiO₂NPs in concentrations of 0.2 μg/mL (red) and 0.2 mg/mL (blue). p <0.05.