Preparation of Sodium Polystyrene Sulfonate Suspension Enema for Treatment of Hyperkalemia.

Enemas of sodium polystyrene sulfonate (SPS) in 20% sorbitol (20% Sor) have regularly been administered by an irrigator for the treatment of hyperkalemia. However, intestinal necrosis, which may be caused by the high osmolality of Sor, has been reported in some patients who received enemas of SPS in Sor.We prepared several SPS suspensions using a 5% glucose solution containing methyl cellulose (MC), hydroxypropyl cellulose (HP) or Avicel RC 591 NF (AB) as a vehicle, and examined the physicochemical properties (dispersibility, osmotic pressure, viscosity and dropping time from irrigator) of each suspension. Among the suspensions tested, the 1% ABG suspension, which was prepared as follows; SPS was suspended in 5% glucose solution containing 1% AB by mixing at 5, 000 rpm for 3 min on a homo mixer, showed the best results. The 1% ABG suspension was isotonic with physiological fluid. A predominant dispersibility of SPS, a low viscosity and a short dropping time from the irrigator were all obtained using this-suspension. The suspension was quite stable for at least 90 days at room temperature.In uremic rats which were made by performing a bilateral nephrectomy, the occurrence of intestinal necrosis and the effect on the serum level of potassium were investigated after the rectal administration of SPS suspensions. No significant pathological changes were noted in rats receiving a 1% ABG suspension. In addition, the 1% ABG suspension caused a significant decrease in the serum level of potassium from the control level.These results suggest that the 1% ABG suspension for enemas of SPS can be useful in the treatment of hyperkalemia.