离子敏感鼻用原位凝胶的制备及其兔消除动力学

 目的制备离子敏感型鼻用原位凝胶剂,研究其在家兔鼻腔内的在体消除动力学。方法采用去乙酰结冷胶为材料制备离子敏感型原位凝胶。考察原位凝胶的微观结构、流变性、持水能力,以^99mTc-DTPA为示踪剂用γ-闪烁照相技术评价原位凝胶在家兔鼻腔中的滞留时间,计算其消除动力学参数。结果0.5%去乙酰结冷胶可制备原位凝胶,其微观结构是由阳离子与去乙酰结冷胶链上的羰基络合形成的双螺旋结构逆向聚集而成的三维网络结构。原位凝胶可明显提高药物在鼻腔内的滞留时间,其AUC_0-t和AUC_0-∞分别是对照制剂的2和7倍。结论应用0.5%去乙酰结冷胶可成功制备离子敏感型鼻用原位凝胶,其在鼻腔中的滞留时间有较显著的延长。

Preparation of Ion-Activated in Situ Gel Systems for Nasal Use and Its Elimination Pharmacokinetic Study in Rabbits

OBJECTIVE To prepare ion-sensitivity in situ gels and investigate its elimination pharmacokinetics in rabbits.METHODS Gels with deacetylated gellan gum (DGG) were prepared.Microstructure of gels was studied by optical microscope.The rheology and the water holding capacity of gels were investigated by viscosity and centrifugal experiement.99mTc-DTPA was used as model drug to investigate the nasal residence time.RESULTS The microstructure of gels was formed by the aggregation of the double helical segments to form a three-dimensional network.The use of polymer such as 0.5% deacetylated gellan gum in nasal dosage forms increased the residence time within the nasal cavity and provided the opportunity for sustained nasal drug delivery.CONCLUSION The gels with 0.5% deacetylated gellan gum are prepared successfully.