In vitro release of RHT (3% w/w) in PBS at 37 °C from Tyr-based gel formulations (300 μL): BTyrOCH3, 0.1 (▲) and 0.05 mmol·g−1 (△); STyrOCH3, 0.1 (■) and 0.05 mmol·g−1 (□), all with a NMP/organogelator molar ratio of 3, and STyrOCH3, 0.05 mmol·g−1 (●), with a NMP/organogelator molar ratio of 6. Mean ± SEM (n = 3).