分光光度法测定阿司匹林片剂中乙酰水杨酸含量的不确定度评定

采用分光光度法测定阿司匹林片剂中乙酰水杨酸的含量,按照测量不确定度的传播规律建立数学模式,讨论了不确定度分量的来源及评定,通过对各相对不确定度分量分析计算,求出合成不确定度(uc)和扩展不确定度(U).建立一种仪器分析实验室不确定度的评定方法.     

红外光谱仪使用中的若干问题

针对红外光谱分析在高校实验教学和科研中,如在有机化学、生物化学、药物学等专业类的实验教学及科研项目中的重要作用及遇到的一些实际问题,根据自己在实际工作中的经历,介绍红外光谱解析的步骤、红外光谱解析中要注意的事项及制样中的一些技巧等.     

Chitosan-g-PAA Hydrogels for Colon-Specific Drug Delivery: Preparation, Swelling Behavior and in vitro Degradability

A series of cross-linked hydrogels for colon-specific drug delivery were synthesized by graft copolymerization of Chitosan and acrylic acid using N, N'-methylene-bis-(acrylamide) as a cross-linker. Their swelling behavior in different pH buffer solutions and colonic enzymatic degradability were studied. The obtained results show that these hydrogels have good pH sensitivity which can avoid drug release in stomach, and their swelling kinetics in stimulant intestinal environment follow second-order swelling k...     

Chitosan-g-PAA hydrogels for colon-specific drug delivery: Preparation,swelling behavior and in vitro degradability

A series of cross-linked hydrogels for colon-specific drug delivery were synthesized by graft copolymerization of Chitosan and acrylic acid using N, N′-methylene-bis-(acrylamide) as a cross-linker. Their swelling behavior in different pH buffer solutions and colonic enzymatic degradability were studied. The obtained results show that these hydrogels have good pH sensitivity which can avoid drug release in stomach, and their swelling kinetics in stimulant intestinal environment follow second-order swelling kinetics equation. The factors influencing the swelling kinetics include the degree of cross-linking and the composition, which may control no release or a little amount release of drug inside the hydrogels in the small intestine by tailoring these factors. The gels are degradable by colonic enzymes and there is a correlativity between the degradation of networks and the swelling degree of the gels, which may trigger the release of drug in the colon. The hydrogels show a great potential for their application in oral colon-specific drug delivery system.     

高效液相色谱仪常用检测器的使用与维护

高效液相色谱是高等院校、药业、食品、环保等各个领域常用的仪器之一。笔者对常用检测器的故障进行分析、同时对示差折光检测器的原理及使用等进行介绍,旨在给从事液相色谱仪使用的人员提供一点参考。