33 factorial design-based optimization of the formulation of nitrofurantoin microcapsules

A microcapsule form of nitrofurantoin was prepared by a simple coacervation method with carboxymethylcellulose and aluminium sulfate. 3³ factorial design was performed for three independent variables, namely, the particle size of the drug, the size of the microcapsules and the pH of the dissolution medium. The dissolution tests with the formulated microcapsules were carried out according to the United States Pharmacopeia XXII rotating basket method at pH 1.2, 5 and 7.5, which represent the pH of gastrointestinal fluids. Release data were examined kinetically and the ideal kinetic models were estimated and t _63.2 values obtained from RRSBW distribution were used in the factorial design experiment. The influence of the independent variables on the dissolution of nitrofurantoin microcapsules could be expressed as the pH of the dissolution medium > particle size of the microcapsule > particle size of nitrofurantoin. The other aim of this study was to evaluate microcapsule formulation in terms of the United States Pharmacopeia criteria with a minimum of experiments. Our findings suggest that dosage forms which comply with the pharmacopoeia criteria for dissolution can be prepared and selected by factorial design.     

蝙蝠葛酚性碱片溶出度方法考察

目的:探讨中药制剂蝙蝠葛酚性碱片的溶出度,为临床用药提供参考。方法:采用紫外分光光度法,分别对其溶出介质、转速进行考察,对累积溶出百分率进行测定,并对3批样品进行均一性试验。结果:蝙蝠葛酚性碱片在45 m in内即溶出70%以上,相对标准偏差在3.0%以内。结论:中药固体制剂蝙蝠葛酚性碱片按照《中国药典》(二部)有关溶出度测定方法控制其内在质量是可行的,可保证临床用药安全、有效。     

Proteolysis and partial dissolution of calcium oxalate: a comparative, morphological study of urinary crystals from black and white subjects

Crystal adherence to the renal epithelium is widely regarded as a probable mechanism of stone formation. Intracrystalline proteins may provide access to the core of urinary crystals and thereby facilitate the dismantling of these crystals after their attachment to and phagocytosis by renal epithelial cells. The present study investigated the role of proteolysis and limited dissolution of urinary calcium oxalate (CaOx) crystals in South Africas white and black populations with a view to understanding the remarkably low stone incidence in the black population compared with the whites. CaOx crystals were precipitated from filtered urine or ultrafiltered urine dosed with an intracrystalline protein, urinary prothrombin fragment 1 (UPTF1), isolated from white and black subjects. The crystals were fractured and subjected to proteolysis and/or limited dissolution before examination using field emission scanning electron microscopy (FESEM). FESEM data showed that CaOx crystals from white and black subjects were eroded by treatment with proteases. Cathepsin D caused the most significant crystal erosion, and more noticeable degradation of CaOx monohydrate (COM) crystals compared to CaOx dihydrate (COD). Limited dissolution studies showed the unique ultrastructures and fragmentation processes of COM and COD crystals. COM crystals appeared to be more susceptible to degradation and dissolution than CODs. Since COMs are predominant in blacks, compared with COD crystals from whites, it is speculated that the lower stone rate amongst South African blacks might be attributed partly to their more efficient destruction of retained COM crystals.     

高效液相法测定曲匹布通片含量及溶出度

目的建立HPLC法测定曲匹布通片含量及溶出度。方法选用PhenomenexCl8柱(250mm×4.60mm,5um),甲醇一醋酸钠缓冲液(取醋酸钠6.13g,加水750ml,加冰醋酸调节pH值至2.5)(60:40)为流动相,检测波长为271nm,流速:1.0mL.min-1,柱温:35℃。结果曲匹布通在7.48～37.42ug.mL-1范围内,线性关系良好,F0.9999,平均回收率为98.9%。结论该法简便、准确、专属,可用于该片的质量控制。     

Crystal dissolution of biological and ceramic apatites

Summary High resolution transmission electron microscopy (Hr TEM) studies on biological and synthetic calcium phosphate have provided information on the dissolution process at the crystal level. The purpose of this study was to investigate the dissolution of ceramic hydroxyapatite (HA) after implantation using Hr TEM. Recovered HA ceramic implanted in bony and nonbony sites in animals and in periodontal pockets in humans were used for the study. For comparison, sections of human fluorotic enamel with caries and sections of shark enameloid previously exposed to 0.1 HCl were similarly investigated. Hr TEM studies demonstrated that in both the biological and ceramic apatites, the lattice and atomic defects were the starting points in the dissolution process. However, significant differences in the process of dissolution were observed: (1) biological apatite crystals showed preferential core dissolution whereas ceramic apatite crystals showed nonspecific dissolution at the cores and at the surfaces; (2) the dissolution of biological apatites appeared to consistently extend along the crystal's c-axis whereas dissolution of the ceramic HA did not appear to be correlated with the crystal's c-axis. The observed differences in crystal dissolution between biological and ceramic apatites may be attributed to the following: (1) the unique crystal/protein interaction present with biological apatites but absent in ceramic HA; (2) differences in defect distribution between biological and ceramic apatites which are due to the differences in the original of these defects; and (3) the longer morphological c-axis of biological apatites compared with that of ceramic apatites. This study provided for the first time, information on the dissolution process of implanted ceramic HA crystals and suggests that the crystal defects resulting from the sintering processes during the preparation of ceramic HA affect itsin vivo degradation and performance.     

盐酸米诺环素软膏的释放度研究

目的探讨盐酸米诺环素缓释软膏的体外释放度及释药机制。方法制备盐酸米诺环素软膏供试品溶液和盐酸米诺环素标准品溶液。释放度采用桨法（《中国药典》2010版二部附录XD第二法）,以水为释放介质,体积为500 mL,转速为100 r/min,温度为（37.0±0.5）℃,检测波长为274 nm。采用紫外分光光度法测定释放介质中盐酸米诺环素的含量。结果盐酸米诺环素检测浓度在0.99～19.87μg/mL范围内具有良好的线性关系,线性回归方程为A=0.0301C＋0.0004,相关系素r=1,平均回收率为101.6%,相对标准偏差为1.5%。在1、4、7 h的释放度分别为13.91%、29.89%、40.76%,体外释放度有良好的缓释药物行为。体外释放特征显示该软膏制剂具有复合释药的规律,一级释放机制所占比例更大一些。结论盐酸米诺环素软膏制剂具有缓释作用,释放度测定方法操作简便、快速、准确度好。     

复方磺胺甲噁唑片体外溶出度考察

目的：测定５ 厂家的复方磺胺甲嚙唑片体外的溶出度,考察产品质量。方法：按中国药典（１９９５ 年版） 分光光度法以０．１ｍｏｌ·Ｌ－１ 盐酸为溶剂溶解。结果：５ 个厂家复方磺胺甲嚙唑的溶出参数Ｔｄ、Ｔ５０ 存在显著性差异（ Ｐ＜ ０．０１）。结论：为控制本产品的内在质量,应增加其溶出度的测定项目。     

α-TCP骨水泥体外溶解动力学研究

研究了α-磷酸三钙(α-TCP)骨水泥在生理盐水体外的溶解动力学。实验结果表明,α-TCP骨水泥静态溶解过程符合Avrami动力学模型方程式：-In(1-x)=kt^1/2,并计算出溶解过程的表观活化能约为9．87kJ／mol．此过程由沉积的羟基磷灰石(HA)固膜扩散控制。     

高效液相色谱法测定普伐他汀钠胶囊的溶出度

目的采用高效液相色谱法测定普伐他汀钠胶囊的溶出度。方法按照《中国药典》2000年版Ⅱ部溶出度测定法中的第二法,以水900 m l为溶剂,转数为50 r.m in-1,30 m in时采样。采样后以高效液相色谱法测定。色谱柱:D iamonsilTMC18(200 mm×4.60 mm,5μm),流动相:磷酸盐缓冲液-甲醇(40∶60)pH 3.5±0.05,流速:1.0 m l.m in-1,检测波长:238nm,以外标法测定普伐他汀钠胶囊的溶出度。结果线性范围为3.0~12.0μg.m l-1(r=0.999 9)。平均回收率为99.86%,(RSD=1.7%,n=6),溶出度符合规定。结论该方法简便、易行,结果准确。     

葛根芩连丸中多糖类溶出度的测定方法

目的：建立测定葛根芩连丸中多糖类溶出度的方法。方法：溶出度的测定用蒽酮硫酸法显色,紫外可见分光光度法在622nm处测定吸光度。结论：多糖的溶出度在45min内达到了70%的标准。结果：测定葛根芩连丸中多糖溶出度的方法简单,可为葛根芩连丸质量评价的研究提供新的参考指标,也为复方制剂中多糖类的含量测定提供参考。