Separation of Dyes by Mixed Hydrotropic Thin Layer Chromatography

Abstract

Now a days, aqueous solubility of drugs is major problem in pharmaceutical field. Generally for solubilization of drugs organic solvents generally prefer. But these solvents are toxic in nature, high cost, flammable and acts as pollutants. Organic solvents are not environment safe. Hydrotropic method is used to enhance water solubility of poorly water soluble drug by using various hydrotropes instead of organic solvents. As a Model sample Bromocresol green and phenol red was selected. To increase water solubility of poorly water soluble dyes, single and mixed hydrotropic method was selected. Both dyes soluble in optimized single hydrotropic solution like as 20% niacinamide, 25% niacinamide, 10% sodium benzoate and mixed hydrotropic solution like 10% Sodium citrate and 10% urea. For separation of both dyes from mixture Thin layer chromatography have been used. Silica gel G used as stationary phase on glass slide and hydrotropic solution used as a mobile phase in which sample was completely soluble. When single hydrotropic solution used as a mobile phase, separation of dyes was not obtained from mixture. Mixed hydrotropic solution of 10% sodium citrate and 10% urea used as mobile phase gives better result. Rf value of Bromocresol green and phenol red in mixed hydrotropic solution was found to be 0.51 and 0.82 respectively.