HPLC法测定复方对乙酰氨基酚片中对乙酰氨基酚、乙酰水杨酸及咖啡因的含量

目的:采用高效液相色谱法测定复方对乙酰氨基酚片中对乙酰氨基酚、乙酰水杨酸及咖啡因的含量。方法:采用 Li-chrospher C_(18)(5 μm,4.6 mm×250 mm)色谱柱,以甲醇-水-冰醋酸(40:60:0.3)为流动相,流速1.0 mL·min~(-1),检测波长272 nm,柱温35℃。结果:对乙酰氨基酚线性范围为19.93～199.32μg·mL~(-1)(r=0.9998),平均回收率(n=9)为99.2%;乙酰水杨酸线性范围为36.00～359.96μg·mL~(-1)(r=0.9999),平均同收率(n=9)为99.7%;咖啡因线性范围为4.90～49.04μg·mL~(-1)(r=0.9998),平均同收率(n=9)为98.8%。结论:方法简使,结果准确,适用于该产品的质量控制。     

The wetting of powders of acetylsalicylic acid,salicylic acid,phenacetin and paracetamol

The wetting of powders of acetylsalicylic acid, salicylic acid, phenacetin and paracetamol has been assessed using methanol-water mixtures to give a range of surface tensions. The results have been interpreted in terms of the critical surface tension, adhesion tension and spreading coefficients. The critical surface tension values are surprisingly low which may be due to adsorption of the methanol at the solid surface, exposing its CH₃ group to the liquid. The adhesion tension and spreading coefficient values could be useful guides in formulation.     

The wetting of powders of acetylsalicylic acid, salicylic acid, phenacetin and paracetamol.

The wetting of powders of acetylsalicylic acid, salicylic acid, phenacetin and paracetamol has been assessed using methanol--water mixtures to give a range of surface tensions. The results have been interpreted in terms of the critical surface tension, adhesion tension and spreading coefficients. The critical surface tension values are surprisingly low which may be due to adsorption of the methanol at the solid surface, exposing its CH3 group to the liquid. The adhesion tension and spreading coefficient values could be useful guides in formulation.     

HPLC assay of acetylsalicylic acid,paracetamol, caffeine and phenobarbital in tablets

This paper present a HPLC method for simultaneous determination of acetylsalicylic acid, paracetamol, caffeine and phenobarbital in tablets, using chromatographic system consisting a Bio Rad 18 01 solvent pump, Rheodine 71 25 injector and Bio Rad 18 01 UV-Vis Detector. Separation was achieved using Bio SiL HL C18, 5 microm, 250 x 4.6 mm column. Mixture of acetonitrile-water (25:75 v/v) adjusted to pH 2.5 with phosphoric acid was used as a mobile phase at a flow rate of 2.0 ml min(-1). UV detection was at 207 nm range 0.01 AUFS. Under the same conditions it was possible to determine the level of salicylic acid. The chromatographic parameters such as retention times, capacity factor, peak asymmetry, selectivity factor and resolution factor was determined. The validation parameters: linearity (r > 0.998), intra-day precision (RSD: 0.36-1.89%) and inter-day precision (RSD: 0.58-2.18%), sensitivity (LOD: 9 x 10(-5)-1.7 x 10(-4) mg ml(-1) and LOQ: 2.5 x 10(-4)-5.6 x 10(-4) mg ml(-1)), accuracy (recoveries: 98.35-99.14%) and reproducibility (recovery values: 98.74-102.08% for acetylsalicylic acid, 99.93-102.11% for paracetamol, 98.25-102.12% for caffeine and 98.15-102.3% for phenobarbital) (RSD: 1.21-1.85%) were found to be satisfactory. The proposed HPLC method has been applied for the determination of acetylsalicylic acid, paracetamol, caffeine and phenobarbital in Malophenum tablets. The obtained RSD values were within 0.99-1.21%. The developed method is rapid and sensitive and therefore suitable for routine control of these drugs in dosage form.     

多元回归分光光度法测定复方乙酰水杨酸片中的非那西丁和咖啡因的含量

目的：观察灯盏花素治疗脑梗塞的疗效。方法：１８０例脑梗塞病人,其中男９５例,女８５例。年龄（６２±７３）ａ。采用灯盏花素注射液１０～２０ｍｌ加入生理盐水５００ｍｌ,静脉滴注,每天１次,１４ｄ为１疗程。隔２～３ｄ进行第２疗程。对照组１１０例,男６８例,女４２例。年龄（６１８±６８）ａ。采用低分子右旋糖酐５００ｍｌ静滴,方法、疗程同治疗组。结果：灯盏花素组总有效率８５％,显效率７３％。右旋糖酐组总有效率７０％,显效率３５％,经Ｒｉｄｉｔ分析：Ｐ＜００５。同时还显示灯盏花素对血脂、血液流变学均有显著改善（Ｐ＜００５）。该药不良反应少。结论：灯盏花素是治疗脑梗塞的良好药物。     

Gas chromatographic analysis of acetylsalicylic acid, phenacetin, caffeine, and codeine in APC and codeine tablets

All active ingredients in APC and codeine tablets are determined by gas chromatographic procedures after separation of acetylsalicylic and phenacetin from caffeine and codeine.     

激素治疗中的药物经济学分析

目的：探讨复方乙酰水杨酸片中非那西丁和咖啡因的含量测定方法。方法：在乙醇中溶解样品,用０２ｍｏｌ／ＬＮａＯＨ水解乙酰水杨酸后,以ｐＨ６５磷酸盐缓冲液为溶剂进行定量,采用多元回归分光光度法。结果：非那西丁和咖啡因的平均回收率分别为９９８％和９９９％,ＲＳＤ为０７２％和０５２％。结论：样品的测定结果同部颁标准法比较在准确度上无显著差异。     

N-way PLS applied to simultaneous spectrophotometric determination of acetylsalicylic acid, paracetamol and caffeine

In this work, a simple and rapid analytical procedure was proposed for simultaneous determination of acetylsalicylic acid (ASA), paracetamol (PRC, also known as acetaminophen) and caffeine (CAF) in pharmaceutical formulations based on multivariate calibration and UV spectrophotometric measurements (210-300 nm). The calibration set was constructed with nine solutions in the concentration ranges from 10.0 to 15.0 microg x ml(-1) for ASA and PRC and from 2.0 to 6.0 microg x ml(-1) for CAF, according to an experimental design. The procedure was repeated at four different pH values: 2.0, 3.0, 4.0 and 5.0. Partial least squares (PLS) models were built at each pH and used to determinate a set of synthetic mixtures. The best model was obtained at pH 5.0. An N-way PLS model was applied to a three-way array constructed using all the pH data sets and enabled better results. This calibration model provided root mean squares errors of prediction (RMSEP) from 11.5 to 35% lower than those obtained with PLS at pH 5.0, depending on the analyte. The results achieved for the determination of these drugs in commercial tablets were in agreement to the values specified by the manufactures and the recovery was between 94.7 and 104.5%.     

Effects of caffeine and paracetamol alone or in combination with acetylsalicylic acid on prostaglandin E(2) synthesis in rat microglial cells

Paracetamol has mild analgesic and antipyretic properties and is, along with acetylsalicylic acid, one of the most popular "over the counter" analgesic agents. However, the mechanism underlying its clinical effects is unknown. Another drug whose mechanism of action is unknown is caffeine, which is often used in combination with other analgesics, augmenting their effect. We investigated the inhibitory effect of paracetamol and caffeine on lipopolysaccharide (LPS)-induced cyclooxygenase (COX)- and prostaglandin (PG)E(2)-synthesis in primary rat microglial cells and compared it with the effect of acetylsalicylic acid, salicylic acid, and dipyrone. Furthermore, combinations of these drugs were used to investigate a possible synergistic inhibitory effect on PGE(2)-synthesis. Both paracetamol (IC(50)=7.45 microM) and caffeine (IC(50)=42.5 microM) dose-dependently inhibited microglial PGE(2) synthesis. In combination with acetylsalicylic acid (IC(50)=3.12 microM), both substances augmented the inhibitory effect of acetylsalicylic acid on LPS-induced PGE(2)-synthesis. Whereas paracetamol inhibited only COX enzyme activity, caffeine also inhibited COX-2 protein synthesis. These results are compatible with the view that the clinical activity of paracetamol and caffeine is due to inhibition of COX. Furthermore, these results may help explain the clinical experience of an adjuvant analgesic effect of caffeine and paracetamol when combined with acetylsalicylic acid.     

Effects of prostaglandin E1 on acid secretion, mucosal histamine content and histidine decarboxylase activity in rat stomach

1. Prostaglandin E(1) inhibits basal and pentagastrin-stimulated gastric acid secretion. The mechanism of this action is not clear. One possible explanation might be that prostaglandin E(1) interferes with the local release or synthesis of histamine which has been proposed as the mediator of the effects of gastrin on the parietal cell.2. A single injection of prostaglandin E(1) did not affect mucosal histamine content or histidine decarboxylase activity in the rat stomach. Pentagastrin lowered the histamine content and activated the histidine decarboxylase to the same extent in prostaglandin E(1)-pretreated and in control rats. We conclude therefore that the inhibitory effect of prostaglandin E(1) on basal and pentagastrin-stimulated acid secretion is not caused by inhibition of histamine release or histamine synthesis.3. Repeated injections of prostaglandin E(1) resulted in a significant elevation of the gastric histidine decarboxylase activity in normal but not in antrectomized rats. Conceivably, this increase in enzyme activity is secondary to prostaglandin E(1)-induced inhibition of acid secretion, which will stimulate release of gastrin due to the rise in intragastric pH.     

Simultaneous determination of paracetamol, caffeine and acetylsalicylic acid by means of a FI ultraviolet pls multioptosensing device

A simple and rapid analytical procedure is proposed for the simultaneous determination of caffeine (CF), acetylsalicylic acid (ASA) and paracetamol (PCT) in pharmaceutical preparations by partial least-squares (PLS) treatment of a flow-through multisensor based on the integration of the retention and UV detection of the analytes on a solid support. Diode-array spectrophotometry has been used to obtain spectra (240-350 nm) of the analytes retained on C18 bonded phase beads packed in a flow cell. By using a 0.5% pH 1 HClO4 solution as the carrier, the multisensor responds linearly in the measuring range without requiring additional reagents or derivatization processes and the active microzone is regenerated by using methanol as eluting agent. Spectra of the corresponding analytes were used to provide multivariate data for the multivariate procedure. The statistical parameters obtained by the application of PLS methods at different reaction times were analysed, from which the optimum reaction time for the simultaneous determination of the analytes was selected. In the analysis of real and synthetic samples, precise and accurate values were obtained.     

Effects of exposure period of acetylsalicylic acid, paracetamol and isopropanol on L929 cytotoxicity

An established fibroblast cell line, L929, was exposed to three substances—acetylsalicylic acid, isopropanol and paracetamol—for 24 hr, 72 hr or 13 days. The effective concentration that caused 50% inhibition of cell growth (EC₅₀) was calculated for both the 24- and 72-hr exposures using three assays—total protein (TP), neutral red uptake (NR) and enzymatic conversion of MTT to formazan. The methods determining the viability of the cells were more sensitive than measurement of total protein. Cells exposed for 13 days continued to proliferate during the entire period, although at a reduced rate, and never attained the density of the control. The relative toxic effect of the substances varied considerably as a consequence of the duration of the exposure period.     

Densitometric determination of propyphenazone, paracetamol, guaiacol glycerol ether, caffeine and acetylsalicylic acid in analgesic-antipyretic preparations with thin-layer chromatography

Optimum conditions for a simultaneous determination of propyphenazone, paracetamol, guaiacol glycerol ether, caffeine and acetylsalicylic acid were described for preparations with analgesic-antipyretic activity, which don't allow a direct determination of the active principle because of interference phenomena. Using an external standard for calibration the determination was carried out by adsorption measurement (reflectance detection) in situ. Beside the determination of the drug content the method can be used to identify substances according to their RT and RF-values as well as by on-plate spectra taken.     

Influence of paracetamol and acetylsalicylic acid on the toxicokinetics of toluene

To study the influence of paracetamol and acetylsalicylic acid on the toxicokinetics of toluene, 2 groups of 10 male volunteers were exposed to toluene vapor (3.25 mmol/m3, 4 hr) at two different exposure occasions: toluene alone and toluene + analgesics. Solvent concentrations in blood and hippuric acid concentrations in urine were measured during the exposure period and 3 hr after exposure. The concentration of toluene in blood increased after ingestion of paracetamol or acetylsalicylic acid, as compared to the control exposure. The ingestion of paracetamol significantly increased the area under the blood concentration versus time curve (P less than 0.05) and the apparent blood clearance was significantly reduced (P less than 0.05) after ingestion of paracetamol but not after ingestion of acetylsalicylic acid. No statistically significant differences in the urinary excretion of hippuric acid were found.     

Effects of caffeine on paracetamol activation in rat and mouse liver microsomes.

1. The effects of caffeine on the NADPH-dependent production of paracetamol-glutathione conjugate were studied in rat and mouse liver microsomes. 2. In the presence of caffeine, glutathione conjugate production in rat microsomes was enhanced, whereas that in mouse microsomes was not affected significantly, showing an apparent species difference. 3. The data partly explain the species difference in the effects of caffeine on paracetamol hepatotoxicity.