維生素C、熊果素以及對苯二酚都是化粧品或是藥品中常見的美白劑，但是這些成分的功效往往會隨著儲存時間增加而逐漸衰退。為了瞭解這些常見的美白劑的活性可以維持多久的時間，因此本研究將三種美白成分置於不同的溶劑環境中並以紫外光可見光分光光度計和酪胺酸酶活性抑制實驗來測試這些成分的安定性。研究結果顯示，維生素C在溶劑為純水/丙二醇（純水等比例混合丙二醇）相對於純水或丙二醇時有較好的安定性以及較高的抑制酪胺酸酶能力。而熊果素與對苯二酚則是在溶劑為丙二醇時，有較好的安定性也呈現較好的抑制酪胺酸酶能力。本研究也提出這三個美白劑在環境中衰退的分子機制，可以提供研究人員以及相關產業人士更進一步瞭解這些美白劑在產品中應用的特性。

Vitamin C, arbutin and hydroquinone were frequently used skin whitening agents of cosmetics and drugs. However, the whitening effect of these molecules is decreased with the storage time. Thus, to establish the relationships between activity and storage time of these skin whitening agents, we analyzed the UV spectrograms and tyrosinase inhibition activity of these whitening agents in different solvents to realize their stability. Our results indicated that vitamin C has the best stability and tyrosinase inhibition activity when it is dissolved by water/propylene glycol (1:1). Besides, arbutin and hydroquinone have the best stability and tyrosinase inhibition activity when they are surrounded by pure propylene glycol. This study also provides the proposed decay mechanisms for vitamin C, arbutin and hydroquinone.which can make people to further understand the application characteristics of them.