氯吡格雷硫酸盐阿司匹林复合片体外溶出度测定

目的建立氯吡格雷硫酸盐阿司匹林复合片体外溶出度测定方法,比较自制片与市售片的体外溶出行为。方法采用紫外-可见分光光度法测定自制片与市售片体外溶出度,用?_2相似因子法评价自制片与市售片溶出曲线的相似性。结果氯吡格雷硫酸盐的质量浓度在2.5～30.0 mg·L^(-1)内与吸光度呈良好的线性关系(r=0.999 9),阿司匹林的质量浓度在5.0～200.0 mg·L^(-1)内与吸光度呈良好的线性关系(r=0.999 7),氯吡格雷硫酸盐与阿司匹林的平均回收率分别为98.76%和99.02%。自制片与市售片在不同介质中?_2相似因子均大于50,两者具有体外溶出一致性。结论所建立的溶出度测定方法高效简便,可用来测定氯吡格雷硫酸盐阿司匹林复合片的溶出度。

联苯双酯固体分散体的制备及表征

目的制备联苯双酯固体分散体,以提高联苯双酯的体外溶出度。方法以聚乙二醇6000(Polyethylene glycol 6000,PEG6000)、聚维酮K30(Povidone K30,PVP K30)和泊洛沙姆188(Poloxamer188,P188)为载体,采用溶剂挥发法制备联苯双酯固体分散体。同时,采用差示扫描量热法(Differential scanning calorimetry,DSC)、X射线粉末衍射法(X-ray powder diffraction,XRPD)和红外光谱法(Infrared Spectroscopy,IR)等技术对固体分散体进行表征。结果在三种载体制备的固体分散体中,联苯双酯的体外溶出度明显提高,且三种载体对联苯双酯的增溶效果依次为:P188>PVP K30>PEG6000。DSC、XRPD和IR结果表明,联苯双酯以分子形式或无定型存在于固体分散体中。结论采用溶剂挥发法制备联苯双酯固体分散体,能明显提高联苯双酯体外溶出度。

EXISTENCE OF SOLUTIONS OF STURM-LIOUVILLE BOUNDARY VALUE PROBLEMS FOR NONLINEAR SECOND ORDER IMPULSIVE DIFFERENTIAL EQUATIONS IN BANACH SPACES

Abstract In this paper, the fixed point theorem is applied to investigate the existence of solutions of Sturm Liouville boundary value problems for nonlinear second order impulsive differential equations in Banach spaces.

PERIODIC BOUNDARY VALUE PROBLEMS FOR FIRST ORDER FUNCTIONAL DIFFERENTIAL EQUATIONS

In this paper, we investigate the periodic boundary value problems for nonlinear first order functional differential equations. By establishing a new comparison result, criteria on the existence of maximal and minimal solutions are obtained.