Interaction of a Cationic Dye “Nile Blue A”
with Bile Salts

Abstract

Bile salts are biologically produced amphiphilic molecules capable of forming micelles. The physiological importance of bile salts lies in their ability to solubilise and emulsify cholesterol, dietary lipids and fat-soluble vitamins in the gastrointestinal tract. Bile salts also have got much recognition as delivery systems for medicines, cosmetics and several other chemicals. The prime factor that makes bile salts good vehicles for drug delivery is its ability to solubilise hydrophobic drugs. Thus, interaction studies of several drugs and model drugs with various bile salts are essential. Nile blue A is a cationic benzophenoxazine dye. The present work aims at the study of the interaction of the cationic dye Nile blue A with bile salts. Absorption studies suggested that bile salts below CMC induce aggregation in the dye. Nile blue showed similar behavior in an anioinic surfactant SDS.