Solubility and Distribution of Dexamethasone Acetate in Oil-in-Water Creams and Its Release from the Creams
キーワード:
vasoconstrictor activity
1985 年 33 巻 9 号 p. 3929-3934
詳細
1985 年 33 巻 9 号 p. 3929-3934
Oil-in-water creams having various capacities to dissolve dexamethasone acetate (DA) were prepared by changing the concentration of polysorbate 80. The solubility of DA in the creams and the distribution of DA in each phase of the creams were examined to see how they influenced DA release from the creams. The solubility of DA in the creams was obtained by calculation from the solubility of DA in each component of the cream. These results on DA release were compared with data on the human vasoconstrictor activity of these creams. In creams of low DA concentration, DA was solubilized, and the DA release rate decreased as the concentration of polysorbate 80 increased, being inversely proportional to the solubility of DA in the cream. On the other hand, in creams of high DA concentration, DA was present partially in the soild state, and the DA release rate increased as the concentration of polysorbate 80 increased. The release rate was dependent on the ratio of solubilized DA in the cream. However, vasoconstrictor activity was dependent on the concentration of free DA in the aqueous phase of the cream.
