The Study of Morphology of Hydroquinone in Whitening Creams by Microcrystalline Technique

Abstract

The purposes of this research were to study morphology of hydroquinone in whitening creams by microcrystalline technique and study reagent concentration for the hydroquinone crystallization test in whitening cream products. In this study, different reagent of sodium-mata periodate (NaIO₄) was tested by using microcrystalline technique. The observation of their color and arrangement of the forming crystals was taken under a polarized light microscope. It was found that the hydroquinone had long slender needle morphology with yellow glow. The five samples of whitening cream products in Thailand included (A) Anti-sunscreen Lotion Tree 3 Day, Pink Bottle, (B) Anti-sunscreen Lotion Tree 3 Day, White Bottle, (C) Miss Days (Day), (D) Mui Lee Haing and (E) Kai Muk Naa Dayng Cream. The optimum reagent concentration were 0.02 M, 0.03 M, 0.02 M, 0.10 M and 0.03 M. The whitening cream product of Kai Muk Naa Dayng Cream was found with no hydroquinone. The results conformed to the results from SURE kit of Faculty of Science Mahidol University. However, consumers should concern about their safety and check the product by test kit which was easy to use in a single-step protocol with clear and rapid results.