Phase behavior characterization of propylene glycol, white petrolatum, surfactant ointments

Abstract

Ointment vehicles consisting of moderate amounts of propylene glycol (5–10%) and large amounts of white petrolatum (greater than 80%) were investigated by determining the ternary phase behavior between these two components and each of five surfactants exhibiting a range of physical properties. The commercial anionic surfactant Pationic SSL performed better as an emulsifier for propylene glycol and white petrolatum than did Lexamul 515, Lexamul AR, Arlacel 20, or Grilloten ZT 40. From this study a formulation consisting of 7% propylene glycol, 90% petrolatum, and 3% Pationic SSL was considered to be an optimized propylene glycol/white petrolatum ointment base.