Rhodamine B was used as a model drug in this study. V₂ phase gels were prepared by hydrating monoolein with rhodamine B stock solution in LB in a 70:30 ratio (m/v) using centrifugation. Briefly, monoolein was transferred to a centrifuge tube, followed by dye solution. The mixture was centrifuged (14,800 rpm; 10 min), mixed with a spatula, and this process repeated until homogenous. Dye-loaded gels were equilibrated at 37 ℃ for 16 h before transferring to individual mini-beakers to simulate release from a single-sided matrix (cross-sectional area: 0.532 cm²). The release matrices were stored at 37 ℃ prior to use.