The procedure to prepare herbal cream was as
follows. Salicylic acid was dissolved in propylene glycol
and glycerin in a beaker. Salicylic acid, as a keratolyic
agent, was used in an acceptable means as suggested
by Thai FDA that salicylic acid in cosmetics with
concentrations of 1 to 1.5% (pH 2.8) was allowed.12 The
oil phase (as shown in Table 1) was melted by heating a
beaker to 65 °C using a water bath. Water phase (as
shown in Table 1) was heated in a separate beaker to 70°C. Once the desired temperature was reached, the oil
phase was added into the water phase. When the
mixture temperature decreased to 40 °C, Germaben II
was added and the mixture was homogenized for 30
min. This resulting smooth cream was then tested for its
viscosity, particle size, pH, physical appearance and
antioxidant activity.