The effect of some surfactants or polymers on the physicochem. properties of emulsion-type suppository bases was investigated.witepsol S-55 [18348884-L], Which is a trilauryl acid glycerin ester derivative, was used as the oil phase.The emulsifiers used were com. grade Amisoft: CS-11, GS-11, and HS-21, and the polymers used were Na alginate [9005-38-3], Na CM-cellulose [9004-32-4] and Na polyacrylate [9003-04-7].In addition, the emulsion stability was evaluated in terms of (1) the rheol. properties, (2) the particle size and its distribution, (3) the mean and distribution of electrophoretic mobility.Amisoft surfactants are excellent emulsifiers when compared with Na dodecyl sulfate or Tweens based on the particle size and viscosity measurements, and the addition of aqueous polymers is effective in stabilizing emulsion bases.Accordingly, emulsion-type bases should be suitable for pharmaceutical use in suppository products.