Abstract:
OBJECTIVE To develop a determination method for the entrapment efficiency of ketoconazole ethosomes. METHODS The content of ketoconazole was determined by HPLC. The minicolumn of filling dextran gel was adopted to separate the free ketoconazole from ethosome dispersions by centrifugation. Chromatographic conditions were as follows: column was Sinochrom ODS-BP(4.6 mm×200 mm, 5 μm) and the mobile phase was acetonitrile-water-triethylamine (60∶40∶0.5, adjust to pH 8.6 using phosphate) with the flow rate of 1.0 mL·min
-1, and detection wavelength was 243 nm. The Dextran G-50 minicolumn was spinned at 2 000 r·min
-1 for 3 min for removing excess amount of water. The 0.2 mL sample added on prepared column was centrifuged at 2 400 r·min
-1 for 5 min, and then washed for 3 times by 0.2 mL of distilled water. RESULTS By flowing through the Dextran G50 minicolumn, the free ketoconazole was adsorbed more than 99.30%, while the average recovery of blank ethosomes was more than 99.49%. CONCLUSION This method is technically simple and rapid to determine entrapment efficiency of ketoconazole ethosomes.