Abstract：
The utilization of Hydroquinone (HQ) in over-the-counter skincare items is subject to restrictions. Consequently, Arbutin (AR) serves as a reliable alternative for addressing hyperpigmentation in non-prescription topical formulations. Nevertheless, AR undergoes decomposition into HQ and p-Benzoquinone (BZ) when exposed to temperature stress, ultraviolet light, or dilution in an acidic environment, all of which can induce skin toxicity. The intention of this paper is to investigate the effect of extraction procedure on the conversion of AR to HQ and or BZ and to evaluate kinetics of AR hydrolysis to HQ. Meanwhile this study aims to evaluate AR and BZ interference with the United States Pharmacopoeia (USP) identification and assessment method for HQ Hydrolytic stress during extraction conditions underwent optimization through systematic screening tests. Subsequent assessment of the residual drug and its degradation products were achieved by HPLC method. The resulting data were meticulously fitted to various kinetic models. To analyze the potential interference of AR in HQ measurement using USP method, the standard concentrations of AR and HQ were analyzed through UV-VIS spectrophotometry. For enhanced certainty, a validated HPLC method analysis was also conducted. Notably, the acid hydrolysis of AR exhibited independence from its initial concentration. So, the hydrolytic degradation of AR exhibited a Zero-order kinetic profile. Furthermore, the proven interference of AR in the UV-VIS spectrophotometry method was identified within the context of the USP method. This study successfully utilized an adopted HPLC method for the concurrent quantification of AR, HQ, and BZ. The potential interference of AR in the UV-VIS spectrophotometric assay for HQ may lead to false results especially for regulatory purposes.
摘要：
在非处方护肤产品中使用氢醌(HQ)受到限制。因此,熊果苷（AR）是解决非处方局部制剂中色素沉着过度的可靠替代品。然而，当暴露于温度胁迫时，AR会分解为HQ和对苯醌（BZ），紫外光,或者在酸性环境中稀释，所有这些都会引起皮肤毒性。本文的目的是研究提取程序对AR转化为HQ和或BZ的影响，并评估AR水解为HQ的动力学。同时，本研究旨在评估AR和BZ干扰与美国药典（USP）鉴定和评估方法对HQ水解应激提取条件进行了系统的筛选试验优化。随后通过HPLC方法对残留药物及其降解产物进行评估。将所得数据精心拟合到各种动力学模型中。使用USP方法分析AR在HQ测量中的潜在干扰，通过UV-VIS分光光度法分析AR和HQ的标准浓度。为了增强确定性，还进行了验证的HPLC方法分析。值得注意的是,AR的酸水解表现出与其初始浓度无关。所以,AR的水解降解表现出零级动力学特征。此外，在USP方法的背景下，确定了AR在UV-VIS分光光度法中的经证实的干扰。本研究成功地利用采用的HPLC方法同时定量AR，HQ,BZ。在用于HQ的UV-VIS分光光度测定中AR的潜在干扰可能导致错误的结果,特别是对于监管目的。
