FORMULATION AND PHYSICAL STABILITY TESTING OF A FACIAL SERUM GEL CONTAINING GOTU COLA (Centella asitica (L.)) LEAF EXTRACT WITH VARIYING OF CARBOMER CONCENTRATIONS AS A GELLING AGENT. OPTIMAL [Internet]. 2026 Feb. 27 [cited 2026 Apr. 14];3(1). Available from: https://proceedings.nuansafajarcemerlang.com/index.php/ico/article/view/178