Abstract
W/O/W type double emulsions stable for a long time were prepared by two-step emulsification procedures using an oily lymphographic agent, Lipiodol Ultra-Fluid, and a derivative of hydrogenated castor oil (HCO-10) as an oil phase. The yield of W/O/W type double emulsions was about 90%. Although the yield was not lowered by vigorous dispersion with a homogenizer, the size of oil droplets was decreased and the release rate of cytarabine was enhanced. Neither the concentration of cytarabine in, nor the volume of, the inner aqueous phase affected the release pattern of cytarabine from W/O/W type double emulsions. The release rate of 5-fluorouracil (5-FU) from the W/O/W type double emulsion was so fast that the release was completed within 1 h. The release of cytarabine and glucose was sustained and peplomycin was hardly released from the W/O/W type double emulsion. W/O type emulsions or W/O/W type double emulsions prepared in this study might be suitable as carriers of drugs such as peplomycin.
