Controlled release potassium chloride tablets

A process for preparing a controlled release tablet of potassium chloride comprising:

• (a) microencapsulating potassium chloride crystals with an inner membrane of ethylcellulose by coacervation or phase separation to form potassium chloride microcapsules;
• (b) coating said potassium chloride microcapsules with an outer membrane comprising a plasticized polymer to form compressible coated microcapsules;
• (c) preparing a compressible blend comprising said compressible coated microcapsules, microcrystalline cellulose (compression aid), and colloidal silicon dioxide;
• and
• (d) compressing said compressible blend into tablets,
• wherein the tablet hardness is at least about 14 kP, the friability of the tablets does not exceed about 0.3% and the tablets exhibit a dissolution profile substantially corresponding to the following pattern when tested by USP Apparatus 2 (Paddles @ 50 rpm) in purified water:
• after 2 hours, about 30% to about 50% of the total potassium chloride is released;
• after 4 hours, about 60% to about 75% of the total potassium chloride is released;
• and
• after 8 hours, not less than 80% of the total potassium chloride is released.