The high speed liquid chromatography (HSLC) was adapted for the stability test of hydrocortisone acetate (HA) in emulsion.
The HSLC conditions were as follows : Model : JASCO FLC-350, Detector : UVIDEC-1, wavelength : 242 nm, Column : JASCOPACK-SV-02-500, Mobile phase : MeOH : H2O (6 : 4), Flow rate : 1 ml/min, Pressure : 70 kg/cm2 and Chart speed : 1 cm/min (at room temperature). Thymolphthalein (TF) was used as a internal standard material. The extracted HA was directly injected to the HSLC column, in which the stationary phase was supported by octadecylsilane.
Six kinds of emulsions containing 1 % HA, which are absorption and hydrophilic ointment of improved, pharmacopeia and commercial grades, were exposed to air at 10°C or 40°C, and then measured their stability to the oxidation by using HSLC.
The result showed that the amount of HA in W/O emulsion decreased, but in O/W emulsion did not change.
Aging effect on the oxidation of six kinds of emulsions was investigated by measuring peroxide value (POV). It was found that POV of W/O emulsions increased and that of O/W emulsions were constant.
