A composition comprising an aqueous suspension comprising an incretin mimetic and an organic acid is described. The organic acid is one that (i) has a water solubility at room temperature of between about 0.01 and 10 g/L, (ii) has a molar mass of less than about 500 grams per mole, and/or (iii) maintains a pH of the suspension in its environment of use of between 3.0-6.0 for a period of at least about 30 days, and stabilizes the incretin mimetic to provide a composition that is suitable for delivering the compound in a biologically active or potent form for a sustained period of time. Devices comprising the compositions and methods of treatment are also described.
