Preparation and evaluation of tamsulosin hydrochloride sustained-release pellets modified by two-layered membrane techniques

The aim of the present study was to develop tamsulosin hydrochloride sustained-release pellets using two-layered membrane techniques.Centrifugal granulator and fluidizedbed coater were employed to prepare drug-loaded pellets and to employ two-layered membrane coating respectively.The prepared pellets were evaluated for physicochemical characterization,subjected to differential scanning calorimetry(DSC)and in vitro release of different pH.Different release models and scanning electron microscopy(SEM)were utilized to analyze the release mechanism of Harnual■ and home-made pellets.By comparing the dissolution profiles,the ratio and coating weight gain of Eudragit■ NE30D and Eudragit■ L30D55 which constitute the inside membrane were identified as 18:1 and 10%-11%.The coating amount of outside membrane containing Eudragit■ L30D55 was determined to be 0.8%.The similarity factors(f_(2))of home-made capsule and commercially available product(Harnual■)were above 50 in different dissolution media.DSC studies confirmed that drug and excipients had good compatibility and SEM photographs showed the similarities and differences of coating surface between Harnual■ and self-made pellets before and after dissolution.According to Ritger-Peppas model,the two dosage form had different release mechanism.

泛昔洛韦缓释微丸体内测定方法的建立及药动学研究

目的：建立泛昔洛韦（FCV）缓释微丸体内血药浓度的测定方法并进行体内药动学研究。方法：以甲醇和0.02mol/L磷酸二氢钾（9∶91）为流动相,选择6条家犬口服泛昔洛韦缓释微丸375mg后,利用高效液相色谱法（HPLC）测定6条家犬的血药浓度并对其进行药动学的研究。结果：本法的线性范围为0.1-10μg/ml,r=0.9943,日内及日间RSD均小于10%。FCV缓释微丸在体内的代谢产物喷昔洛韦（PCV）的tmax为（4.80±0.84）h,Cmax为（2.61±1.37）mg/L,AUC0→∞为（25.59±7.58）mg/h/L,MRT为（9.85±2.47）h。结论：本方法简便快速,无干扰,重现性好,可用于泛昔洛韦在体内的药动学研究,并且通过本实验的体内测定方法得到了家犬体内的药动学参数。

泛昔洛韦缓释微丸的研制

以Eudragit RSPO和RLPO为缓释材料,采用流化床包衣技术制备了泛昔洛韦缓释微丸。采用单因素试验筛选了增塑剂种类及用量、抗黏剂粒度、Eudragit RSPO和RLPO的配比及老化时间。所得优化参数为两种包衣材料配比19∶1,增塑剂为10%聚乙二醇6000,抗黏剂为20%滑石粉(1 250目),包衣增重25%,老化12 h。所制缓释微丸在1.5 h(0.1 mol/L盐酸)、3 h和8 h(pH 6.8磷酸盐缓冲液)的累积释放度分别为10%～30%、30%～70%和70%以上。药动学研究表明,本品与泛昔洛韦普通片相比具有明显的缓释特征。