Matondang , F.H., Lubis, M.S., Yuniarti , R. and Rani, Z. 2025. Formulation of used tea bags nano powder facial mask and antibacterial activity against Propionibacterium acnes and Staphylococcus epidermidis. Journal of Pharmaceutical and Sciences. 8, 1 (Jan. 2025), 1–21. DOI:https://doi.org/10.36490/journal-jps.com.v8i1.685.