Aluminium and calcium lake pigments of Lac natural dye

This work presents the physicochemical properties of the prepared lac lakes. The study revealed the stability, cytotoxicity and use of lac lake pigment as a cosmetic colorant. SEM, XRD and DSC were used to study the characteristics of the lac lakes.. The color stability of lac dye and its lakes was investigated at ambient temperature and at 45 °C, in sunlight,fluorescent light and darkness, for 3 months. Cytotoxicity on human dermal skin fibroblast cell lines was tested using MTT assay and the use of the lakes as a colorant in lip color product was studied. Different metal salts resulted in lac lakes of different shades and appearance. SEM, XRD and DSC results indicated that the morphology and structure of lac dye were changed after reacting with metal salts which support the coordination of metal ion with lac dye. The lac lakes were not cytotoxic to human dermal skin fibroblast cells (0.78-100 µg/mL). Lac lakes exhibited less alteration of color shade over acidic and basic conditions when compared with the lac dye itself. Additionally, the lake pigments displayed better color stability than lac dye and produced an orange-brown shade of lip color product. The results suggest that lac lake pigments have good potential for use as cosmetic colorant.