Abstract
In general, it is recognized that emulsion-type bases have outstanding characteristics for suppository products as compared with simple hydrophilic or hydrophobic bases. The purpose of this work was to investigate the effect of some surfactants or polymers on the physicochemical properties of emulsion-type suppository bases. Witepsol S-55, which is a trilauryl acid glycerin ester derivative, was used as the oil phase. The emulsifiers used were commercial grade Amisoft ; CS-11, GS-11, and HS-21, and the polymers used were sodium alginate, sodium carboxymethylcellulose and sodium polyacrylate. In addition, the emulsion stability was evaluated in terms of (1) the rheological properties, (2) the particle size and its distribution, (3) the mean and distribution of electrophoretic mobility. It was found that (1) Amisoft surfactants are excellent emulsifiers when compared with sodium dodecyl sulfate or Tweens based on the particle size and viscosity measurements, and (2) the addition of aqueous polymers is effective in stabilizing emulsion bases. Accordingly, emulsion-type bases should be suitable for pharmaceutical use in suppository products.
