DEVELOPMENT OF OIL VEHICLE SCREENING METHOD FOR BROMO ACID DYE-BASED COLOR-CHANGING COSMETICS FORMULATION

• Main Author: Rana Wulan Sujilah, Ajeng
• Format: Theses
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/82663
• Institution: Institut Teknologi Bandung

Bromo acid dyes, such as Red 21 are recently gaining attention in color-changing cosmetic formulations. The critical aspect in the development of cosmetic products using this dye group is the selection of its oil vehicles. In previous research, oils screening method have been developed through the approach of determining the correlation between the relative polarity of oil vehicle and the solubility of Red 21. The results of the correlation are considered moderate and sufficient to predict the compatibility of oil vehicle with Red 21 dye. Oil carriers must possess the capability to dissolve bromo acid dyes, produce mixes with low color intensity and exhibit color alteration in response to variations of environment and pH. This study devised a screening technique to evaluate the color-changing ability of oil carriers in cosmetics. The method employed solubility characteristics and absorption spectrum analysis. The screening procedure involved conducting the Red 21 solubility test at a concentration of 0.02%, examine the absorption spectrum of Red 21 in oil carriers and their interactions, as well as the Red 21 color-changing test. The test results were classified into four distinct categories:soluble and interaction (SI), soluble and no interaction (SNI), insoluble and interaction (NSI), and insoluble and no interaction (NSNI). The SI group provides a clear and mild-color solution, while the SNI group gives a vibrant color. Oils classified as SI and SNI induce color alteration in the aqueous phase indicating the significant role of solubility on color change. The SI and SNI groups are suitable oil vehicle for bromo acid dye-based color-changing cosmetics because it dissolves bromo acid and produces a transparent liquid that changes colour when exposed to skin pH.