Formulasi serum penghambat kerja tirosinase yang mengandung fitosom ekstrak biji lengkeng (Dimocarpus longan Lour) menggunakan Eksipien Koproses Kasein-Xanthan Gum = Formulation of serum for tyrosinase inhibition containing phytosome of longan seed extract (Dimocarpus longan Lour) using coprocessed of Casein-Xanthan Gum as excipient / Noorviana Farmawati