Identification Retinoic Acid Content in Online Whitening Cream Sold in Samarinda City Using Thin Layer Chromatography (TLC) and Spectrophotometry UV-Visible Methods. JPS [Internet]. 2022 Jul. 30 [cited 2026 Oct. 24];5(2):174-80. Available from: https://journal-jps.com/new/index.php/jps/article/view/2121