The drug olsalazine (H(4)olz) was employed as a ligand to synthesize a new series of mesoporous metal-organic frameworks that are expanded analogues of the well-known M-2(dobdc) materials (dobdc(4-) = 2,5-dioxido-1,4-benzenedicarboxylate; M-MOF-74). The M-2(olz) frameworks (M = Mg, Fe, Co, Ni, and Zn) exhibit high surface areas with large hexagonal pore apertures that are approximately 27 angstrom in diameter. Variable temperature H-2 adsorption isotherms revealed strong adsorption at the open metal sites, and in situ infrared spectroscopy experiments on Mg-2(olz) and Ni-2(olz) were used to determine site-specific H-2 binding enthalpies. In addition to its capabilities for gas sorption, the highly biocompatible Mg-2(olz) framework was also evaluated as a platform for the delivery of olsalazine and Other encapsulated therapeutics. The Mg-2(olz) material (86 wt % olsalazine) was shown to release the therapeutic linker through dissolution of the framework under simulated physiological conditions. Furthermore, Mg-2(olz) was used to encapsulate phenethylamine (PEA), a model drug for a broad class of bioactive compounds. Under simulated physiological conditions, Mg-2(olz)(PEA)(2) disassembled to release PEA from the pores and olsalazine from the framework itself; demonstrating that multiple therapeutic components can be delivered together at different rates. The low toxicity, high surface areas, and coordinatively unsaturated metal sites make these M-2(olz) materials promising for a range of potential applications, including drug delivery in the treatment of gastrointestinal diseases.