Slow releasing injection contg. antiparasitic medicine

A slow-releasing injection containing antiparasitic medicine is prepared from the dispersed solid particles consisting of large-ring lactone type antihelmintic and hydrogenated castor oil (HCO), the dispersing medium chosen from water, 1,2-propanediol, propanetriol and glycerine triacetate, and optional non-ionic surfactant and suspending aid. Its advantage is high slow-releasing effect.