氟罗沙星的体内外试验相关性研究

本文研究了新型喹诺酮类药物氟罗沙星体外溶出与体内吸收之间的相关性。实验表明，本品口服吸收在血清中达峰时间较快，作用持久，消除半衰期为９．６０ｈｒ。在人工胃液中溶出速率较快，在血清达峰之前，体内吸收与体外溶出量之间呈现良好的相关性。     

白霉素片溶出度实验研究

本文采用转蓝法紫外分光光度法测定了三家药厂七批白霉素片体外溶出度,求得T_(50),Td威布尔函数参数具有显著差异,表明不同厂家所生产的白霉素片的溶出度相差显著,提出了影响药物溶出的某些因素,建议国产白霉素片有必要制定溶出标准。     

Gallstone recurrence after direct contact dissolution with methyltert-butyl ether

To determine the rate and characteristics of gallstone recurrence after direct contact dissolution with methyltert-butyl ether, 60 consecutive patients were followed for up to 4.5 years (median 2.2 years) after complete disappearance of all stone residues and debris and cessation of adjuvant bile acid therapy. Initial gallstones had been multiple in all but four patients. Twenty-eight of the 60 patients developed recurrent gallstones. The cumulative risk of gallstone recurrence (actuarial analysis) was 23±6%, 34±7%, 55±8%, and 70±9% at one, two, three, and four years, respectively. The recurrent stones were usually multiple and small (6±4 mm). Gallstone recurrence was associated with recurrent biliary pain in two patients, one of whom developed acute cholecystitis. Recurrent stones were cleared completely by bile acid medication with or without shock-wave lithotripsy in 61±15% of patients at one year (actuarial analysis). In conclusion, gallstone recurrence after successful contact dissolution of multiple stones with methyltert-butyl ether has to be expected in a high percentage of patients. Most patients, however, remain free of biliary pain during long-term follow-up.     

A polyexponential deconvolution method. Evaluation of the “gastrointestinal bioavailability” and meanin vivo dissolution time of some ibuprofen dosage forms

A new deconvolution algorithm (DCON) suitable for pharmacokinetic applications is presented. It requires that both the impulse and input responses, typically systemic drug levels, be well described by polyexponential equations. DCON has a wider range of applications than an earlier method (DECONV) from which it is derived. A FORTRAN program is provided, making implementation of the technique a simple matter. DCON is demonstrated to evaluate the GI bioavailability, defined as the rate and the extent of gastrointestinal drug release, of various ibuprofen dosage forms. The GI drug release kinetics exemplifies a pharmacokinetic system which cannot be evaluated using the previous deconvolution algorithm (DECONV) because of an initial zero drug level response. This limitation is not found in DCON. It is also demonstrated how the mean in vivo dissolution time MDT can be evaluated by deconvolution.     

Dissolution test for felodipine tablets using chemical oxidation in situ to maintain 'sink conditions'

A test model is described for the determination of the dissolution rate of the vasodilator, felodipine, a derivative of dihydropyridine that is practically insoluble in water. ‘Sink conditions’ are maintained by means of an oxidizing agent, ceric sulphate, which reacts rapidly with dissolved drug molecules in the dissolution fluid. A pyridine derivative is formed quantitatively in the oxidation reaction. The amount of dissolved felodipine is calculated from the concentration of the pyridine derivative, as determined by reversed-phase liquid chromatography. Dissolution rates depend on the concentration of the oxidizing agent so that high concentrations accelerate dissolution. The dissolution test suggested for 25-mg felodipine tablets is performed in 500 ml fluid that contains 5 mM ceric sulphate in 0.12 M sulphuric acid. The test is performed on single tablets with USP paddle equipment. Dissolution rates for nine different tablet compositions are correlated to such bioavailability parameters as maximum plasma concentration and total area under the plasma concentration—time curve. Interferences and limitations of the method are discussed.     

甲硝唑口颊片的工艺研究

采用正交试验设计,考察处方工艺中羧甲基纤维素钠的用量、筛网的大小和片剂的硬度对甲硝唑口颊片的质量影响,从而优选甲硝唑口颊片的最佳处方和制备工艺。制备的甲硝唑口颊片各项指标均符合质量标准,20、50和90min的释放度分别为33．4％、54．3％和74．1％。     

葛根黄豆苷元分散片的制备及其溶出度测定

对葛根黄豆苷元片进行工艺改进,制成分散片,以提高其溶出度,并通过探讨葛根黄豆苷元片溶出度检查方法的稳定性、均一性、重现性、回收率试验等,确立测定葛根黄豆苷元片溶出度的最佳条件。     

高效液相色谱法考察复方头孢氨苄胶囊的溶出度

采用反相高效液相色谱外标法,对复方头孢氨苄胶囊溶出度进行考察。方法：采用转篮法,以4％乙酸溶液为溶剂,转速为100r/min,时间为45min。色谱条件：C18反相谱柱为固定相,V（水）：V（甲醇）：V(3．86％乙酸钠溶液）：V(4％乙酸溶液）＝742：240：15：3为流动相,流速为1.2mL/min,紫外检测波长为254nm,在此条件下头孢氨苄淀两组分能很好地分离。本法的线性范围分别是头孢氨苄为：27．6－276μg/mL,甲氧苄啶为：5．56－ 55．6μg/mL,平均回收率为头孢氨苄：99．32％,RSD＝0．78％;甲氧苄啶：100．1％,RSD＝0．57％。     

光纤化学传感器—计算机联用实时在位测定氧氟沙星片体外溶出度

目的：探索一种连续在位测定固体制剂溶出度的新方法和新理论。方法：应用芘丁酸光纤化学传感器和计算机联用在线技术及中国药典（1995版）规定的紫外分光光度法（UV）分别测定氧氟沙星片剂的体外溶出度。结果：在药典规定的测定浓度范围内有良好的线性,相关系数0．9980。方法的日内、日间精密度（RSD）分别为1．18％和1．56％,当信噪比为3时检测限为0．56μg/ml。用中国药典（1995版）规定的紫外分光光度法作对照并进行评价,P＞0．05,显示两种方法所得结果无显著性差异。结论：本法改变传统的取样分析模式,实现了响应快速、准确、灵敏的过程分析。     

尼莫地平固体分散片溶出度比较

以进口尼莫地平薄膜包衣片为参考 ,比较国内两厂家的尼莫地平固体分散片溶出度。以乙醇∶水 (15∶85 )为溶出介质 ,在 (37± 0 5 )℃下 ,浆法 ,进行溶出实验 ,采用紫外分光光度法测定并计算结果。各厂家尼莫地平片 30min内溶出度不低于 70 %。经t检验 ,3种样品组间 4 5min溶出度无显著性差异 (P >0 0 5 )。