环境水样中痕量铜的浊点萃取-火焰原子吸收光谱测定法

目的建立环境水样中痕量铜的浊点萃取(cloud point extraction,CPE)-火焰原子吸收光谱(flame atomic absorption spectrometry,FAAS)测定法。方法样品在p H 9.5的条件下,加入0.4 ml的1 mmol/L 2-(5-溴-2-吡啶偶氮)-5-二乙氨基酚(5-Br-PADAP)溶液,0.1%氯化钙溶液0.1 ml,5%(W/V)Triton X-114溶液0.8 ml,40℃加热15 min后离心,采用火焰原子吸收光谱法进行检测。结果在2~240μg/L的线性范围内,所得回归方程为A=0.002 7c+0.024 6,r=0.995 8。以3倍信噪比计算,方法的检出限为0.62μg/L,富集倍数为36.58倍,平均加标回收率为96.28%~98.08%,RSD为1.67%~3.13%。结论该方法简单、灵敏,具有良好的重现性,适用于环境水样中痕量铜的测定。     

Biopharmaceutics classification and intestinal absorption of chikusetsusaponin IVa

The objective of this study was to investigate the absorption behavior of chikusetsusaponin IVa (CHS‐IVa) in the rat intestine using single‐pass intestinal perfusion (SPIP) and to classify CHS‐IVa into the biopharmaceutics classification system (BCS). The equilibrium solubility of CHS‐IVa was determined by the shaker method. The absorption mechanism of CHS‐IVa in the intestine was studied by comparing the P_eff of different concentrations of CHS‐IVa. The intestinal site dependence of CHS‐IVa absorption was studied by comparing the P_eff of the same concentration of CHS‐IVa in different intestinal segments. The relationship between CHS‐IVa and intestinal efflux protein was studied by perfusion with an efflux protein inhibitor. The permeability of CHS‐IVa was investigated by comparing the P_eff of CHS‐IVa and the reported value. The solubility of CHS‐IVa over the pH range 1.0–7.5 was 14.4 ± 0.29 to 16.9 ± 0.34 mg/ml. The P_eff of CHS‐IVa in the duodenum was 1.76 × 10^?3 to 2.00 × 10^?3 cm/min. The P_eff of CHS‐IVa in the jejunum was 1.26 × 10^?3 to 1.39 × 10^?3 cm/min. The P_eff of CHS‐IVa in the ileum was 1.25 × 10^?3 to 1.31 × 10^?3 cm/min. The P_eff of CHS‐IVa in the colon was 1.02 × 10^?3 to 1.08 × 10^?3 cm/min. There was no statistical difference of the P_eff in the four segments at different CHS‐IVa concentrations. The P_eff of CHS‐IVa (0.07, 0.7 and 7.0 mg/ml) were all notably smaller than the reported P_eff (3.00 × 10^?3 cm/min) in the jejunum. The P_eff of CHS‐IVa was not influenced by verapamil (P‐gp inhibitor), indomethacin (MRP inhibitor) and pantoprazole (BCRP inhibitor). CHS‐IVa was classified as high solubility, low permeability and BCS III. The main absorptive tracts were the upper intestinal tracts and the rank order of intestinal permeability was duodenum > jejunum ≈ ileum > colon. The transport mechanism of CHS‐IVa in all intestinal segments might be primarily passive transport. CHS‐IVa was not a substrate of P‐gp, MRP and BCRP.     

清热解毒液雾化吸入防治留置胃管致咽喉部不适的疗效观察

目的观察清热解毒液(中药制剂)雾化吸入对防治留置胃管致咽喉部疼痛、痰多等不适的效果。方法将80例需要留置胃管的胃肠减压的病人随机分为对照组和观察组各40例。对照组按常规的方法进行护理,观察组在常规护理的基础上加用20毫升清热解毒液雾化吸入,每日2次,持续到拔除胃管。结果观察组病人的咽喉部痰量明显比对照组少(χ2=9.0383,P<0.005);观察组病人咽喉部疼痛明显比对照组少而且轻(χ2=19.5267,P<0.005),时间还推后。结论清热解毒液雾化吸入能有效预防及减轻留置胃管致咽喉部的疼痛、咽燥、痰多等不适。     

Pharmacokinetic profile of tamsulosin OCAS

The tamsulosin oral‐controlled absorption system (OCAS®) is a new tablet formulation of the α₁‐adrenoceptor (α₁‐AR) antagonist tamsulosin, which is used for treating lower urinary tract symptoms (LUTS) suggestive of benign prostatic hyperplasia (BPH). The tablet uses the OCAS technology, which was specifically designed to give a more continuous 24‐h release of tamsulosin, resulting in a more consistent and continuous 24‐h plasma concentration, a lower maximum plasma concentration (C_max) and an independence of pharmacokinetics (PKs) on food intake. It was expected that the improved PK profile would translate into a better control of day‐ and night‐time symptoms of BPH and a lower risk of adverse events. Phase I PK studies showed that tamsulosin OCAS indeed has a flattened PK profile with a lower C_max and a more stable and consistent 24‐h concentration of tamsulosin, independent of food intake, compared to conventional tamsulosin. A study combining γ‐scintigraphy and PK analysis of blood samples confirmed that the improved PK profile of tamsulosin OCAS is attributed to the tablet being consistently and continuously released throughout the entire gastrointestinal tract, including the colon.     

Preclinical Drug Metabolism in the Age of High-Throughput Screening: An Industrial Perspective

With the advent of genomics, combinatorial paradigms and high-throughput screen (HTS)-based pharmacological testing, the number of compounds flowing through the discovery pipeline is likely to escalate. At the same time, with increased knowledge of the human drug-metabolizing enzymes and the availability of in vitro absorption-metabolism (AM) models, Preclinical Drug Metabolism is poised to meet the challenges of HTS. In order to be successful, however, a rational HTS strategy (vs. serendipitous HTS) has to be employed. Such a strategy is based on automation, validation and integration of in vitroAM models and database management (AVID). A generalized strategy for rational (AVID-based) HTS in Preclinical Drug Metabolism is described briefly.     

猕猴对不同极化方向微波辐射能量吸收的研究

为提供微波辐射安全标准必要的数据，研究了不同极化方向微波辐射能量对猕猴的影响。实验在医学微波无反射室中进行，分为电场，磁场和微波传输方向极化组，辐射频率１ＧＨｚ，用红外热图技术，对暴露在三种极化方向电磁场中猕猴面部各解剖特片部位及胸部在辐射前后进行温度变化的定量分析。     

Dermal absorption of niclosamide in rats and minipigs

The dermal absorption of niclosamide, a drug shown to prevent Schistosomiasis by blocking the dermal penetration of cercariae, has been examined in Sinclair minipigs and rats. Radioactivity in the urine and feces collected daily for 7 days after application of 14C-niclosamide accounted for less than 2 per cent and 10 per cent of the labelled compound applied to pig and rat skin, respectively. Approximately 20 per cent of the radioactivity from the dose solution was recovered on the skin excised from the area of application in both minipigs and rats. No radioactivity was detected in organs removed from the pig 7 days after application of radiolabelled drug while less than 6 per cent of the dose could be accounted for in the rat organs/carcass. Radioactivity in swine blood, removed 0.5, 1, 2, 4 and at 24 h intervals after dosing, was at or below three times background in all of the samples. Total recovery of the applied radioactivity was 78 per cent in pigs and 57 per cent in rats. These studies indicate that niclosamide is very poorly absorbed after dermal application. The results are consistent with earlier comparative studies showing that dermal penetration of xenobiotics in rats is generally higher than in swine.     

Buffering the stomach content enhances the absorption of diflunisal in man

Diflunisal, a lipophilic salicylate, is absorbed more slowly in healthy volunteers than aspirin. In this paper we report on attempts to influence diflunisal absorption by buffering the gastric milieu. Sodium bicarbonate given together and 30 min after diflunisal tablets significantly (p less than 0.05) shortened the time to reach peak plasma concentration (tmax greater than 15 per cent), raised maximum plasma concentration slightly (Cmax 6 per cent) and increased the area under the plasma concentration-time curve (AUC greater than 8 per cent). Other pharmacokinetic parameters, including terminal half-life and renal elimination of the compound, were not considerably influenced. These findings indicate that the absorption of diflunisal was enhanced by increased gastric pH, presumably a result of an increased solubility of diflunisal in the stomach together with faster transport into the small intestine. In one volunteer, after intravenous administration diflunisal plasma concentrations declined in a triphasic manner with a terminal half-life of 12.8 h. The volume of distribution was approximately 10 per cent of body weight. Based on the ratio of AUC after equivalent i.v. and oral diflunisal doses, the absolute bioavailability was 89.5 per cent.     

Validation of a Flow-Through Diffusion Cell for Use in Transdermal Research

A flow-through finite-dose diffusion cell has been designed for use in transdermal drug delivery research. The diffusion cell consists of an upper donor chamber and a lower receiver compartment through which a continuous supply of fresh solvent flows. The flow is directed to an automatic fraction collector. To validate the flow-through cell, its performance was compared directly against that of a conventional single-reservoir Franz cell. Homologous alkyl p-aminobenzoates were diffused through dimethylpolysiloxane membranes, and permeability coefficients increased with increasing chain length, reaching a plateau at the butyrate ester for both types of cells. This behavior suggests a shift from membrane-controlled diffusion to boundary layer control. Permeation of the butyrate and valerate compounds was significantly faster when the flow-through cell was used, suggesting that better mixing is obtained through the flow-through cell design. Considering the advantages offered in terms of time and labor saved through its use, the flow-through cell with automatic fraction collector appears to be a viable alternative to the conventional Franz cell.