The effect of aluminum hydroxide dissolution on the bleeding of aluminum lake dyes

Pharm Res. 1993 Oct;10(10):1458-60. doi: 10.1023/a:1018971208521.

Abstract

The effect of pH on the bleeding of FD&C yellow No. 5 aluminum lake and FD&C red No. 40 aluminum lake was investigated. The pH-bleeding profiles corresponded to the pH-solubility profile of aluminum hydroxide. The similarity of the bleeding profiles of both lake dyes and the pH-solubility profile of aluminum hydroxide indicates that pH related bleeding, other than that occurring by competition with anions, is a result of dissolution of the aluminum hydroxide substrate. This dissolution is related to the properties of the substrate rather than to the structure of adsorbed dye.

MeSH terms

  • Aluminum Hydroxide / chemistry*
  • Azo Compounds / chemistry*
  • Coloring Agents / chemistry*
  • Hydrogen-Ion Concentration
  • Solubility
  • Tartrazine / chemistry*

Substances

  • Azo Compounds
  • Coloring Agents
  • Allura Red AC Dye
  • Aluminum Hydroxide
  • Tartrazine