A unit dosage form, such as a tablet for delivering potassium into the body in a controlled release fashion, comprises of a multiplicity of microencapsulated potassium chloride crystals, which are further coated with a plasticized polymer to improve compressibility of the microcapsules. The compressible microcapsules are blended with a compression aid, such as microcrystalline cellulose and a glidant, such as colloidal silicon dioxide, to form controlled release potassium chloride tablets. The tablets may optionally include other excipients such as surfactants and disintegrants. The tablets thus produced exhibit not only high crushing strength and low friability but also release potassium in humans in a desired controlled release fashion similar to commercially available potassium chloride tablets.