壳聚糖基卡托普利的合成及其释药研究
2018-07-18李和平肖青秦龙
李和平 肖青 秦龙

摘 要:克服水溶性药物的突释现象,可减少给药次数,提高疗效.本研究以卡托普利为模型药物,壳聚糖为载体,采用耦合的方法,设计合成了壳聚糖卡托普利和壳聚糖赖氨酰卡托普利两种新的键连型壳聚糖基载药体系,产物结构经IR、1H NMR和MS表征;并测试了两种化合物在PBS缓冲溶液(pH=7.4)和HCl-KCl缓冲溶液(pH=1.2)中72 h的累積释药率:壳聚糖卡托普利的累积释药率分别为59.2%和78.4%,壳聚糖赖氨酰卡托普利的累积释药率分别为55.2%和76.4%.结果表明,两种键连型载药体系均消除了突释现象,具有很好的缓释效果,这将有望成为水溶性药物的理想载药体系.
关键词:卡托普利;壳聚糖;合成;缓释
中图分类号:TB383文献标志码:A
Abstract:In order to overcome the burst release of water-soluble drugs, reduce dosing frequency and improve curative effect,two new bond-linking type drug-loaded control-releasing systems: Chitosan-Captopril and Chitosan-Lysyl-Captopril were synthesized from captopril as a model drug and chitosan as carriers. The products were characterized by IR, 1H NMR and MS. The accumulation of drug release rates of Chitosan-Captopril are 59.2% in PBS buffer (pH=7.4) and 78.4% in HCl-KCl buffer (pH=1.2). The accumulation of drug release rates of Chitosan-Lysyl-Captopril are 55.2% in PBS buffer (pH=7.4) and 76.4% in HCl-KCl buffer (pH=1.2). The results show that the two kinds of drug-loaded systems eliminate the phenomenon of burst releasing and have excellent sustained release properties, which are expected to become the ideal control-releasing system of water-soluble drugs.
Key words:captopril; chitosan; synthesis; slow-releasing
卡托普利是一种有效的血管紧张素转化酶(ACE)抑制剂,用于治疗高血压和充血性心脏衰竭[1].但游离态的卡托普利容易氧化[2],且由于卡托普利的水溶性较好导致其生物半衰期仅为1.6~1.9 h,需要日服3~4次,摄入总量达到37.5~75.0 mg[3].临床上为了保持有效治疗浓度,通常采用增加剂量以延长体内作用时间,从而导致“波峰波谷”现象,可能引起眩晕、头疼、胃肠道紊乱等不良反应.因此,通过控制药物释放速率来减少峰谷差异及给药次数,减轻不良反应的意义重大.
目前,调节卡托普利释放速率的方式主要是将其制成包衣片、微丸或微囊等缓释剂型[4] :1)将卡托普利与难溶于水的高分子化合物混合压缩成丸剂.如将卡托普利与羟丙基甲基纤维素,以及CaHPO4和 PEG 6000等辅剂混合均匀,然……
