Study on Dispersion Technology of Pigment Powder and Its Interaction Based on Octenyl Succinate Starch and Arabic Gum Complex

High concentrations of pigment powders present significant challenges for dispersion stability in cosmetic formulations, the dispersion of iron oxide yellow paste may lead to flocculation, reducing its stability. This study employed octenyl succinate starch (OSA starch) and Arabic gum (AG) as composite wall materials to encapsulate iron oxide yellow and to optimize the dispersion system for water-soluble pigment powders. Transmission electron microscopy (TEM) and scanning electron microscopy (SEM) confirmed the formation of a well-structured microcapsule, significantly smaller than the original iron oxide yellow particles. Accelerated stability tests indicated that the microcapsule structure enhanced system stability, with improved performance observed at higher OAF solution concentrations. The contact angle measurements, which were consistently below 90°, demonstrated that the microcapsule structure enhanced the wettability and hydrophilicity of the OAF solution, thereby improving skin adhesion. The encapsulation of iron oxide yellow using OSA starch and AG underscores the potential application of natural hydrocolloids and modified starches in the cosmetics industry.