地塞米松-葡聚糖酯大鼠体内结肠靶向性

目的：建立地塞米松—葡聚糖酯(DSD)体内含量测定方法，并考察DSD体内结肠靶向性。方法：以Sprague-Daule雄性大鼠为实验动物，灌胃给药法分别给予DSD(实验组)和相当剂量的地塞米松(DEX)(对照组)，高效液相色谱法(HPLC)考察血液、胃、近端小肠、运端小肠、育肠、结肠内容物中DEX分布情况。结果：DSD给药后，血液及胃内容物中游离DEX含量显著低于对照组，盲肠、结肠中药物含量百分率分别为44．35％-83.31％，10．22％-20．52％，远过错高于对照组(盲肠，结肠药物含量百分率分别为0．05％-24．67％，0．79％-3．15％)。结论：DSD经盲肠、结肠中特异性酶类水解后释放出游离DEX，大大降低了DEX的全身吸收，具有良好的结肠靶向性。

Study on the function of dexamethasone-succinate-dextran for colon targeting in rats

OBJECTIVE To develop a sensitive RP-HPLC method for the determination of dexamethasone-succinate-dextran (DSD) in rats,and to evaluate the colon targeting property of DSD. METHODS Distribution of Dexamethasone (DEX) in plasma and lumina contents of GI tract was measured by HPLC after oral gavage of DSD or equivalent dose of DEX to male Sprague-Dauleg rats. RESULTS After oral administration of DSD, the recovery of DEX in plasma and gastric contents was significantly lower than that of control group, while the percentage of DEX content in caecum and colon (44. 35% ~83.31% and 10.22% -20.52% respectively) was much higher than that of control group(0.05% ~24.67% and 0.79% ~3.15% respectively). CONCLUSIONS DSD can obviate drug absorption in upper GI tract and shows a good colon targeting property.