内盐凝胶的制备及对烟酰胺的控释

以甲基丙烯酸二甲基氨基乙酯（DMAE-MA）、衣康酸（IA）、亚甲基双丙基酰胺（BIS）和过硫酸钾（KPS）为原料在室温下制备内盐凝胶。研究了原料配方对凝胶形成的影响、内盐凝胶的吸水动力学及溶胀机制、凝胶的pH值敏感性以及对烟酰胺的负载与负载凝胶在不同pH值介质中的释放行为,并用红外光谱对凝胶结构进行了表征。结果表明,n（IA）/n（DMAEMA）〉1后将降低单体的转化率,不利于凝胶的形成;内盐凝胶不具有高吸水性,其吸水溶胀机制符合Fickian扩散;在pH值为12的缓冲溶液中溶胀率比在pH值为3的缓冲溶液中高;凝胶对烟酰胺的负载率可以超过200%。在25℃下,烟酰胺在pH值为3的介质中释放比在pH值为12的介质中释放快。

Preparation of internal salted hydrogels and controlled release of nicotinamide

Internal salted hydrogels were prepared at room temperature using 2-(dimethylamino) ethyl methacrylate(DMAEMA) and itaconic acid(IA) as monomers,N,N-methylene bis(acrylamide)(BIS) as crosslinker,potassium persulfate(KPS)as initiator.The influence of recipe on the formation of hydrogels,the swelling kinetics and swelling mechanism in water,pH sensitivity and their loading and release behavior of nicotinamide in media of different pHs were investigated.The chemical structure of hydrogel was characterized by FT-IR.The results showed that the total monomer conversion reduced and the formation of hydrogels was more difficult when n(IA)/n(DMAEMA) was more than 1.The internal salted hydrogels were not of super water–uptake–ability and their swelling mechanism was fit for Fickian process.The swelling ratio of internal salted hydrogels in pH value 12 buffer solution was higher than that in pH value 3 buffer solution.The nicotiamide loading rate of internal salted hydrogels could exceed 200%.At 25℃,the release of nicotiamide in pH value 3 medium was faster than that in pH 12 value medium.