Armi FS, Uju U, Tarman K. Optimization of the functional beverage formula from nipah leaves (Nypa fruticans) using simplex lattice design method and in vitro immunostimulatory activity: Optimasi formula minuman fungsional dari daun nipah (Nypa fruticans) menggunakan metode simplex lattice design dan aktivitas imunostimulatori in vitro. JPHPI. 2026;29(8):740-754. doi:10.17844/j50e3f37