A robust, highly water stable (up to 3 weeks), microporous MOF, [Zn₈(O)₂(CDDB)₆(DMF)₄(H₂O)] {where CDDB = 4,4′-(9-H carbazole-3,6-diyl)dibenzoic acid}, was synthesized based on an open N–H site by a solvothermal process and exhibited an outstanding loading capacity (around 53.3 wt%) and satisfactory release capability (64.9% and 81.9%) for 5-fluorouracil, constituting a negligible cytotoxicity effect.