Metformin hydrochloride (Met) was combined with iron(III) chloride and trimesic acid (1,3,5-benzene tricarboxylic acid, BTC) as an organic linker in a short and simple method, providing a MOF in which the drug is a part of the constituent. For stabilization and pH-controlled release properties, sodium alginate was applied to coat the MOF surface; this approach led to an increase in drug loading, a decrease in Met release in media having pH similar to stomach pH, a decrease in potential side effects, and an increase in its bioavailability in the intestine.