Quantification of Arbutin in Cosmetics, Drugs and Food Supplements by Hydrophilic-Interaction Chromatography

Abstract

Arbutin, the glucoside of hydroquinone, exists in two isomers, α-arbutin and β-arbutin. The synthetic α isomer is mainly used as a skin brightening agent, while β-arbutin occurs naturally, for instance in bearberry, and is used in drugs for treatment of lower urinary tract infections and as a food supplement. Since both isomers can be harmful at high concentrations, methods for their quantification are required. Classically they have been determined by reversed-phase chromatography, but separation of both isomers is often unsatisfactory. Here we present a simple and reliable method for quantification of α- and β-arbutin based on hydrophilic-interaction chromatography. Prior to analysis, interfering compounds that would frequently be present in cosmetics and drugs, particularly biopolymers, were efficiently removed by precipitation with acetonitrile. In this paper, for separation, a Cyclobond I 2000 5 µm 250 × 4.6 mm column was employed as stationary phase and acetonitrile/water 92/8 (v/v) was used as an eluent at a flow rate of 0.8 mL min−1. For quantification, a UV detector operating at 284 nm was applied. Although analysis took less than 10 min, baseline separation of α- and β-arbutin was achieved. The response was highly linear (r > 0.999) and the method had, for both α- and β-arbutin, a LOD of 0.003% (w/w) and a LOQ of 0.009% (w/w). Moreover, the method showed excellent intra-day and inter-day repeatability with relative standard deviations in the range of 0.5% to 2.3% and 1.0% to 2.2%, respectively, with cosmetics, drugs and food supplements as samples.

Cosmetic and Pharmaceutic Products with Selected Natural and Synthetic Substances for Melasma Treatment and Methods of Their Analysis

“…Arbutin, which is commonly used in skin-whitening products, has limitations on its allowable content due to the fact that it can generate hydroquinone during the decomposition process. Therefore, appropriate analytical techniques based on chromatography [198], fluorescence spectroscopy [199], and cyclic voltammetry [200] have been developed to precisely control the content of arbutin in cosmetic products.…”

Fluorescence-Coupled Techniques for Determining Rose Bengal in Dermatological Formulations and Their Application to Ex Vivo Skin Deposition Studies

“…Other investigations mainly employed the UV-Vis spectrophotometer technique to determine RB content [ 31 , 41 , 42 , 43 , 44 ]. Many dermatological formulations contain biopolymers and lipids that must be removed before the analysis to mitigate any potential interference or matrix effect, which may interfere with RB quantification [ 45 ]. However, based on the chemical profile of RB, the complete isolation from excipients is not always successful, and some undesired traces can remain in the sample for analysis.…”