Estimation of Sodium Lauryl Sulphate Concentration in Marketed Formulations by Stability Indicating ‘Green’ Planar Chromatographic Method

Abstract

Sodium lauryl sulphate [SLS] is a most commonly used toothpaste detergent and responsible for wetting and cleansing action but slightly higher concentration in toothpaste may cause harmful effects. A newly developed ‘green’ high performance thin layer chromatographic (HPTLC) process for the fast estimation of SLS in bulk form and in marketed products was established and validated by using silica gel as the stationary phase. The mobile phase employed for this study is a mixture of environment-friendly solvents butanol, hexane, and glacial acetic acid in 7:2:1 (V/V/V) ratio. The developed method was validated for various validation parameters like linearity, accuracy, precision, robustness, solution stability, recovery and specificity. The very good linearity was obtained between the linear regression data for the calibration plots. LOD as well as LOQ were calculated and found to be 31 and 92 ng/band respectively. Statistical treatment of the obtained data for different validation parameters indicated that the developed ‘green’ HPTLC process is appropriate, reproducible and selective for the quantification of SLS in bulk as well as in marketed products. The utility of the developed method was tested by an assay of SLS in commercially available toothpaste. One of the most striking features of this study was the use of environmentally benign solvents as eluent to explore the migration behavior of SLS.