P(AA-co-PEGLA)凝胶对吡罗昔康的控释作用

将两亲性大单体聚氧乙烯月桂醇醚丙烯酸酯（PEGLA）与丙烯酸（AA）通过UV引发聚合，制备了水凝胶P(AA-co-PEGLA)。以水难溶性吡罗昔康为模型药物，研究了凝胶中PEGLA含量对载药量的影响。结果表明：吡罗昔康的载药量随着PEGLA含量的增加而提高，当凝胶中的PEGLA的摩尔分数(x)从0增加到60%时，载药量从1.24 mg/g提高到17.36 mg/g。吡罗昔康体外释放研究表明：P(AA-co-PEGLA)凝胶可保护药物不被胃酸等破坏，而在肠中释放。药物的释放速率随着凝胶中PEGLA含量的增加而降低，表现出明显的缓释作用。用Weibull方程拟合释放曲线，指数因子(b)0.88~0.97，表明对吡罗昔康释放的控制是扩散和高分子链松弛协同作用的结果。

Controlled Release of Piroxicam with P(AA-co-PEGLA) Hydrogels

P(AA-co-PEGLA) hydrogels were prepared through UV initiated polymerization of acrylic acid (AA) and amphiphilic macromonomer polyethylene glycol monolaurylether monoacrylate (PEGLA). A poorly water-soluble drug piroxicam was chosen as model drug and the drug loading was investigated. The loading of piroxicam is increased with the increasing of PEGLA content. When the mol fraction of PEGLA increase from 0 to 60%, the loading amount of piroxicam increase from 1.24 mg/g to 17.36 mg/g. The drug release behavior shows that piroxicam is protected in gastric condition and release in intestinal condition. With the increasing of PEGLA content in the hydrogels, the release rate reduces. The Weibull equation was used to fit the release data. The estimated b ranges between 0.88 and 0.97, indicating that drug transport mechanism involved both the Fickian diffusion and polymer chain relaxation.