 The study aimed to optimize the chitosan nanoparticles, CSNPs, to enhance the topical delivery and therapeutic potential of alpha-arbutin, alpha-arbutin, a skin whitening agent used for treating melasma. The study found that the pH of chitosan and tripolyphosphate, TPP, solutions affects the particle size, polydispersity index, and Zeta potential of the CSNPs. Additionally, the study showed that the particle size of CSNPs decreases when the pH of chitosan and TPP solutions is adjusted. Furthermore, the study demonstrated that the loading efficiency of alpha-arbutin into CSNPs is greater than that of TPP. This article was authored by Shima Hatem, Nada El-Hafi, Ria Melezebi, and others.