Exploration of Acemannan as a Phytomarker for Aloe barbadensis Gel and its Estimation in Different Marketed Cosmeceutical Formulations

Abstract

Aloe barbadensis (Aloe vera) is a well-known plant belonging to family liliaceae with rich source of anthraquinone glycosides and polysaccharides. Aloe vera is used extensively in the cosmetic and healthcare industries. However estimation of active constituents of aloe in any of the marketed product is not reported yet because of lack of availability of suitable phytomarker. Hence, in the present investigation attempts have been made to identify phyto-marker from the aloe juice and exploration of identified marker as tool for estimation of aloe in marketed cosmeceutical products. From the published research report it has been observed that activity of aloe vera is due to the presence of several phytonutrients and polysaccharides like acemannan. Acemannan, specifically in aloe vera has been identified but not explored extensively as a marker for detection of aloe vera gel in cosmeceutical formulations. Further, the estimation technique based on spectroscopy i.e. nuclear magnetic resonance (NMR) / fourier transform infrared (FT-IR) and chromatographic i.e. gel chromatography/size exclusion high performance liquid chromatography (SE-HPLC) has been reported for estimation of acemannan, but these techniques require sophisticated instruments and are expensive as well as laborious which make them unsuitable for routine quality control checks for acemannan in the formulations. In view of the reported constraints, the present work focuses on a development and validation very simple and sensitive colorimetric assay method for estimation of acemannan in an aloe vera containing products with extended calibration curve for improved detection. In present exploration, estimation sensitivity of acemannan was enhanced by derivatization using congo red dye which make stable congo red-aloe polysaccharide chromogenic complex. Three formulations namely Lab scale developed cream, Marketed Formulation 1 and Marketed Formulation 2 were studied with acemannan as a phytomarker for aloe vera. The developed spectrophotometric method accurately measured acemannan in the sample, which was implicated by stable red color in the presence of Congo red. Overall proposed spectrophotometric technique for determination of aloe polysaccharide in different formulations was found to be robust, accurate, sensitive and precise for routine quality analysis of aloe vera in cosmeceuticals formulation.