灵芝发酵液酸性醇提物抗慢性支气管炎疗效的研究

通过灵芝发酵液酸性醇提物对小鼠的镇咳、祛痰实验,及烟熏小鼠肺部组织的形态学观察,研究灵芝酸性醇提物抗慢性支气管炎的疗效。灵芝发酵全液,不同剂量的灵芝酸乙醇提取物、灵芝酸正丁醇提取物均能显著延长二氧化硫诱发的小鼠咳嗽潜伏期,并显著抑制小鼠咳嗽次数,有明显的镇咳作用。60mg/kg给药量的正丁醇提取物使小鼠气道酚红排泄量较对照组提高了50.7%,祛痰疗效也明显优于双黄连口服液。肺组织切片病理检查表明,灵芝酸性提取物明显减轻烟熏小鼠的气管、支气管粘膜损伤,慢性支气管炎的组织病理学变化明显轻于单纯烟熏模型组,且抗炎、抗损伤作用与双黄连相当,这可为灵芝酸产品的研究开发提供一定的药理依据。     

Characterization of Streptozotocin-induced Diabetic Rats and Pharmacodynamics of Insulin Formulations

Morphological and functional changes of rat pancreatic islets caused by administration of streptozotocin (STZ) and the bioavailability of insulin formulations administered to STZ-induced diabetic rats with fasting (12 h) or non-fasting were investigated. Islets isolated from normal rats maintained a good three-dimensional structure and the islet yield was 962.5±86.5 islet equivalent number (IEQ, islets converted to an average diameter of 150 μm). In the diabetic group (>500 mg/ml blood glucose), the islet yield was only 44.4±8.3 IEQ and the islet was severely damaged. The minimum reduction of blood glucose of each formulation, such as insulin solution, microcrystal, and insulin microcrystal capsule, was shown to be 11.3, 11.0, and 16.3 mg/dl, respectively, at 6 h in fasting with diabetic rats. These results indicated that the administration of insulin formulations to the fasting groups increased the severe hypoglycemic effect of insulin action more than in non-fasting diabetic rats. The diabetic rat with fasting has a regulatory disorder in maintaining the blood glucose level. Accordingly, the validity of pharmacological availability as an optimal modeling of insulin formulations is best in non-fasting STZ-induced diabetic rats.     

Enantioselective pharmacokinetics of (R)‐ and (S)‐ketamine after a 5‐day infusion in patients with complex regional pain syndrome

Introduction: This study determined the pharmacokinetics and pharmacodynamics of (R)‐ and (S)‐ketamine and (R)‐ and (S)‐norketamine following a 5‐day moderate dose, as a continuous (R,S)‐ketamine infusion in complex regional pain syndrome (CRPS) patients. Materials and methods: Ketamine was titrated to 10–40 mg/h and maintained for 5 days. (R)‐ and (S)‐Ketamine and (R)‐ and (S)‐norketamine pharmacokinetic and pharmacodynamic studies were performed. Blood samples were obtained on Day 1 preinfusion, and at 60–90, 120–150, 180–210, and 240–300 min after the start of the infusion, on Days 2, 3, 4, 5, and on Day 5 at 60 min after the end of infusion. The plasma concentrations of (R)‐ and (S)‐ketamine and (R)‐ and (S)‐norketamine were determined using enantioselective liquid chromatography–mass spectrometry. Results: Ketamine and norketamine levels stabilized 5 h after the start of the infusion. (R)‐Ketamine clearance was significantly lower resulting in higher steady‐state plasma concentrations than (S)‐ketamine. The first‐order elimination for (S)‐norketamine was significantly greater than that of (R)‐enantiomer. When comparing the pharmacokinetic parameters of the patients who responded to ketamine treatment with those who did not, no differences were observed in ketamine clearance and the first‐order elimination of norketamine. Conclusion: The results indicate that (R)‐ and (S)‐ketamine and (R)‐ and (S)‐norketamine plasma concentrations do not explain the antinociceptive activity of the drug in patients suffering from CRPS. Chirality, 2011. © 2010 Wiley‐Liss, Inc.     

Cladribine inhibits a diltiazem-induced increase in red blood cell purine nucleotide concentrations in a zebrafish model

Minimizing drug interactions is paramount to improving the efficacy and tolerability of cancer therapy. The zebrafish represents an innovative cancer model due to highly conserved genetics and inherent capacity for high-throughput chemical screening. This pilot study extends the utility of the zebrafish to a preclinical model for pharmacodynamics by examining the interaction of the nucleoside analogue, cladribine with the calcium channel blocker, diltiazem. Cladribine (0.7–3.5?mM) and/or diltiazem (2.4?mM), was injected intraperitoneally into adult zebrafish and red blood cell (RBC) lysates were assayed by HPLC for levels of purine nucleotides (e.g. ATP), potential biomarkers of cardiovascular health. Diltiazem increased RBC ATP concentrations, which were inhibited by co-injection of cladribine. These results suggest a novel drug interaction and highlight the feasibility of the zebrafish as an in vivo model for pharmacodynamic studies.     

Wolman disease/cholesteryl ester storage disease: efficacy of plant-produced human lysosomal acid lipase in mice

Lysosomal acid lipase (LAL) is an essential enzyme that hydrolyzes triglycerides (TGs) and cholesteryl esters (CEs) in lysosomes. Genetic LAL mutations lead to Wolman disease (WD) and cholesteryl ester storage disease (CESD). An LAL-null (lal(-/-)) mouse model resembles human WD/CESD with storage of CEs and TGs in multiple organs. Human LAL (hLAL) was expressed in Nicotiana benthamiana using the GENEWARE expression system (G-hLAL). Purified G-hLAL showed mannose receptor-dependent uptake into macrophage cell lines (J774E). Intraperitoneal injection of G-hLAL produced peak activities in plasma at 60 min and in the liver and spleen at 240 min. The t(1/2) values were: approximately 90 min (plasma), approximately 14 h (liver), and approximately 32 h (spleen), with return to baseline by approximately 150 h in liver and approximately 200 h in spleen. Ten injections of G-hLAL (every 3 days) into lal(-/-) mice produced normalization of hepatic color, decreases in hepatic cholesterol and TG contents, and diminished foamy macrophages in liver, spleen, and intestinal villi. All injected lal(-/-) mice developed anti-hLAL protein antibodies, but suffered no adverse events. These studies demonstrate the feasibility of using plant-expressed, recombinant hLAL for the enzyme therapy of human WD/CESD with general implications for other lysosomal storage diseases.     

Time-kill assay of itraconazole against Malassezia species

The in vitro pharmacodynamic activity of itraconazole against Malassezia was determined by time-kill methods. Itraconazole showed fungistatic activity at concentrations greater than 2x minimum inhibitory concentration (MIC) for each of the isolates of all nine Malassezia species associated with humans. A concentration exceeding 4x MIC decreased the growth to less than the inoculum amount (1 x 10(5) cells/ml).     

Influence of nicorandil on the pharmacodynamics and pharmacokinetics of gliclazide in rats and rabbits

Chronic diabetes precipitates ischaemic heart disease (IHD) and many other disorders. IHD inturn is shown in the form of angina initially. According to EUROPA study, the incidence of angina is high in type II diabetics. Gliclazide, a second generation sulphonylurea derivative is widely used in the treatment of type-II diabetes and is known to release insulin by K⁺ channel inhibition. Nicorandil, a newer antianginal drug widely used now a days acts by opening potassium channels in the cardiac muscle cell and also by releasing nitric oxide. However its action on pancreatic cell K⁺ channel is not known. Since there is possibility for drug interaction leading to decreased activity of gliclazide the present study was conducted to evaluate the effect of the combination.Studies in normal and alloxan induced diabetic rats were conducted with oral doses of 2 mg/kg bd. wt. of gliclazide, 1.8 mg/kg bd. wt. of nicorandil and their combination with adequate washout periods in between treatments. Studies in normal rabbits were conducted with 5.6 mg/1.5 kg bd. wt. of gliclazide, 1.4 mg/1.5 kg bd. wt. of nicorandil and their combination given orally. Blood samples were collected in rats from retro orbital puncture at 0, 1, 2, 3, 4, 6, 8, 10 and 12 h and by marginal ear vein puncture in rabbits at 0, 1, 2, 3, 4, 6, 8, 12, 16, 20 and 24 h. All the blood samples were analysed for glucose by GOD/POD method. The blood samples of rabbits were analysed by HPLC for gliclazide.Gliclazide produced hypoglycaemic/antidiabetic activity in normal and diabetic rats with peak activity at 1 h and 8 h and hypoglycaemic activity in normal rabbits at 3 h, while nicorandil alone produced significant hyperglycaemia at 4 h and reduced the effect of gliclazide with no significant change in pharmacokinetics when administered in combination. The interaction observed appears to be pharmacodynamic at the receptor level as expected.     

Factors affecting the pharmacokinetics and pharmacodynamics of liposomal drugs

Various attempts to increase the therapeutic index of the drug while minimizing side effects have been made in drug delivery systems. Among several promising strategies, liposomes represent an advanced technology to target active molecules to the site of action. Rapid clearance of circulating liposomal drugs administered intravenously has been a critical issue because circulation time in the blood affects drug exposure at the target site. The clinical use of liposomal drugs is complicated by large intra- and interindividual variability in their pharmacokinetics (PK) and pharmacodynamics (PD). Thus, it is important to understand the factors affecting the PK/PD of the liposomal formulation of drugs and to elucidate the mechanisms underlying the variability in the PK/PD of liposomal drugs. In this review article, we describe the characteristics of liposome formulations and discuss the effects of various factors, including liposome-associated factors, host-associated factors, and treatment on the PK/PD of liposomal agents.     

Bioanalytical strategy used in development of pharmacokinetic (PK) methods that support biosimilar programs

The development of biosimilar products is expected to grow rapidly over the next five years as a large number of approved biologics reach patent expiry. The pathway to regulatory approval requires that similarity of the biosimilar to the reference product be demonstrated through physiochemical and structural characterization, as well as within in vivo studies that compare the safety and efficacy profiles of the products. To support nonclinical and clinical studies pharmacokinetic (PK) assays are required to measure the biosimilar and reference products with comparable precision and accuracy. The most optimal approach is to develop a single PK assay, using a single analytical standard, for quantitative measurement of the biosimilar and reference products in serum matrix. Use of a single PK assay for quantification of multiple products requires a scientifically sound testing strategy to evaluate bioanalytical comparability of the test products within the method, and provide a solid data package to support the conclusions. To meet these objectives, a comprehensive approach with scientific rigor was applied to the development and characterization of PK assays that are used in support of biosimilar programs. Herein we describe the bioanalytical strategy and testing paradigm that has been used across several programs to determine bioanalytical comparability of the biosimilar and reference products. Data from one program is presented, with statistical results demonstrating the biosimilar and reference products were bioanalytically equivalent within the method. The cumulative work has established a framework for future biosimilar PK assay development.     

PPARα转基因小鼠在药物评价中的应用研究

目的研究过氧化物酶体增殖激活受体α激动剂药物在PPARα转基因小鼠体内对肝肾功能、血脂指标的影响,以评价该模型能否能应用于药效学研究中。方法选择27只6周龄的PPARα小鼠给予高脂饲料喂养一个月,随机分成3组,9只/组,分别为对照组1,高剂量组（非诺贝特60 mg/kg）和低剂量组（30 mg/kg）。同时选择9只C57BL/6小鼠作为对照组2。连续灌胃一个月,在动物给药前后分别检测肝功能指标、肾功能指标和血脂指标,并观察动物的一般生长情况。结果①给药后各组比较：与对照组1比较,非诺贝特各剂量组在PPARα转基因小鼠体内均能明显升高血脂中CHO和HDL-C（P〈0.05）,明显降低TG（P〈0.05）。各组之间的体重没有明显的差异（P〉0.05）。②给药前后比较：与给药前比较,给药后高剂量组能明显降低ALT、AST、ALP、BUN、TG（P〈0.05）;能明显升高CHO、HDL-C（P〈0.01）。而低剂量组能明显降低ALP（P〈0.05）;能明显升高CHO、HDL-C（P〈0.05）。结论 PPARα转基因小鼠评价PPARα激动剂药物比常规C57BL/6小鼠更敏感,是一个新的动物模型。