RP-HPLC法同时测定桂枝茯苓胶囊中3种成分的含量

目的建立RP-HPLC法同时测定桂枝茯苓胶囊中没食子酸、白芍苷和芍药苷含量。方法色谱柱:大连中汇达C18柱(4.6 mm×250 mm,5μm),流动相:乙腈-体积分数为0.1%的磷酸溶液,梯度洗脱,流速:1.0 mL.min-1,检测波长:230 nm,柱温:40℃。结果没食子酸、白芍苷和芍药苷的线性分别为0.69~6.87 mg.L-1(r=0.999 6)、0.88~8.80 mg.L-1(r=0.999 6)和2.00~20.00 mg.L-1(r=0.999 5)。平均回收率:没食子酸为99.7%(RSD=1.0%,n=9)、白芍苷为101.5%(RSD=1.5%,n=9)、芍药苷为100.0%(RSD=0.7%,n=9)。结论此方法可为桂枝茯苓胶囊的质量控制提供方法。     

Simultaneous determination of seven major diterpenoids in Pseudolarix kaempferi by high-performance liquid chromatography DAD method

A reversed phase high-performance liquid chromatography method was established for the first time to simultaneously qualify the seven major diterpenoids in Pseudolarix kaempferi, namely pseudolaric acid B O-beta-D-glucopyranoside (1), pseudolaric acid C2 (2), pseudolaric acid C1 (3), deacetylpseudolaric acid A (4), pseudolaric acid A O-beta-D-glucopyranoside (5), pseudolaric acid B (6) and pseudolaric acid A (7). The optimal conditions of separation and detection were achieved on an Inertsil ODS-3 column with gradient elution of methanol and 0.5% aqueous acetic acid (v/v) at the flow rate of 0.6 ml min(-1) within 40 min and detection wavelength set at 262 nm. All calibration curves showed good linear regression (r2>0.9999) within test ranges. This method provided good accuracy with recoveries in the range of 94.3-106.1% and good precision with R.S.D.s of repeatability and intermediate precision less than 0.57% and 4.67%, respectively. The method was successfully applied to qualitative and quantitative determination of 20 P. kaempferi among the 54 samples collected from different areas. The results revealed that the commercial crude drugs were seriously confused and the developed HPLC assay could be used as a suitable qualitative and quantitative determination method for P. kaempferi.     

RP-HPLC法同时测定心宁片中芍药苷、阿魏酸和芦丁的含量

目的建立同时测定心宁片中芍药苷、阿魏酸和芦丁含量的RP-HPLC法。方法采用RP-HPLC法,以甲醇-乙腈-质量分数为1%的冰醋酸水溶液(体积比为25∶3∶70)为流动相,色谱柱为Diamonsil C18(200 mm×4.6 mm,5μm),流速为1.0 mL.min-1,柱温为35℃,检测波长为230nm。结果芍药苷、阿魏酸和芦丁分别在51.02~510.20、1.08~10.80和19.04~190.40 mg.L-1内,质量浓度与峰面积呈良好的线性关系,相关系数分别为0.999 9、0.999 9和0.999 6。方法平均回收率(n=9)分别为100.5%(RSD=1.0%)、100.4%(RSD=0.8%)和100.4%(RSD=0.9%)。结论RP-HPLC法可为心宁片的质量控制提供依据。     

Simultaneous determination of mepivacaine,tetracaine, and p-butylaminobenzoic acid by high-performance liquid chromatography

INTRODUCTION: The purpose of the present study was to develop a simple method for the simultaneous determination of mepivacaine, tetracaine, and p-butylaminobenzoic acid (BABA) in human plasma using high-performance liquid chromatography (HPLC) with a multiwavelength detector. METHODS: Human blood samples containing heparin, as an anticoagulant, and physostigmine (100 microg/ml), as an anticholinesterase, or human plasma containing physostigmine were spiked with various concentrations of mepivacaine, tetracaine and, in some cases, BABA. Blood samples were centrifuged and plasma was deproteinized with trifluoroacetic acid (TFA; 7%). After centrifugation, the pH was adjusted to 4.5 and an aliquot of 20, 50 or 100 microl was injected into the HPLC apparatus. The detection was done simultaneously at wavelengths of 214 and 300 nm. Analytical chromatography was done on a Waters microBondapak C(18) reverse-phase column (3.9 x 300 mm; particle size 10 microm) with a 30-min increasing linear gradient of 20-40% acetonitrile+0.05% TFA in H(2)O+0.05% TFA at a flow rate of 1 ml/min. The Waters HPLC system included two pumps, an automatic injector, a column oven, and a M490 multiwavelength detector. Quantification was done using integration of peak areas with peaks of authentic mepivacaine, tetracaine, and BABA standards. RESULTS: Calibration curves for standards of mepivacaine, tetracaine, and BABA were linear in the concentration ranges from 0.1 to 100 microg/ml, and the correlation coefficients exceeded.99 for all compounds. The lower limits of detection were 100 ng/ml for mepivacaine and 50 ng/ml for tetracaine and BABA. The yields for mepivacaine, tetracaine, and BABA were 91+/-2.1%, 82+/-3.3%, and 88+/-2.0% (mean+/-S.E.M., n=6), respectively. Degradation of tetracaine by human plasma at 37 degrees C was inhibited by physostigmine. DISCUSSION: The method is sensitive enough to allow blood concentration determinations of mepivacaine and tetracaine or its metabolite, BABA, following local anesthesia induced by these two drugs, especially when their toxic effect may be present. This method also may be useful in forensic medicine for determination of the cause of death after local anesthesia with mepivacaine and/or tetracaine.     

HPLC-PDA法同时测定更年宁中芍药苷、阿魏酸、黄芩苷和丹皮酚的含量

目的建立HPLC-PDA法同时测定更年宁中芍药苷、阿魏酸、黄芩苷和丹皮酚的含量。方法采用Phenomsil C18(4.6 mm×250 mm,5μm)色谱柱;流动相:以乙腈为流动相A,以0.15%磷酸为流动相B,采用梯度洗脱;流速为1.0 mL·min~(-1);柱温为35℃;芍药苷的检测波长为230 nm,阿魏酸的检测波长为320 nm,黄芩苷的检测波长为280 nm,丹皮酚的检测波长为274 nm。结果芍药苷、阿魏酸、黄芩苷、丹皮酚浓度分别在5.077～50.77、0.297～2.97、8.976～89.76、3.37～33.70μg·mL~(-1)与峰面积线性关系良好,平均回收率分别为98.5%(RSD=0.83%)、98.4%(RSD=1.5%)、98.9%(RSD=1.1%)、98.4%(RSD=1.0%)。结论该方法简便、灵敏、结果准确可靠,可为其提高质量控制标准提供参考。     

超高效液相色谱法同时测定白芍中芍药苷和芍药内酯苷的含量

目的 采用超高效液相色谱法(UPLC)同时测定白芍中芍药苷和芍药内酯苷的含量.方法 采用Agilent Extend-C18(4.6 mm×50 mm,1.8μm)色谱柱,以流动相乙腈(A)-0.2％乙酸溶液(B)梯度洗脱;柱温30℃;流速0.5 mL·min-1;检测波长230 nm.结果 芍药苷和芍药内酯苷分别在0.011 6～1.45(r=0.999 9)、0.008～lmg·mL-1(r=0.999 9)呈良好的线性关系;平均回收率分别为98.6％、97.5％,RSD分别为1.4％、2.2％.结论 该法快速简便,灵敏度高,准确可靠,可用于白芍中有效成分含量的快速测定及白芍的质量控制.     

Simultaneous analysis of dehydroacetic acid, benzoic acid, sorbic acid and salicylic acid in cosmetic products by solid-phase extraction and high-performance liquid chromatography

A high-performance liquid chromatographic (HPLC) method for simultaneous determination of dehydroacetic acid (DHA), benzoic acid (BA), sorbic acid (SOA) and salicylic acid (SA) was developed for application to cosmetic products. Isocratic reversed-phase HPLC was employed for quantitative analysis using tetra-n-butylammonium (TBA) hydroxide as an ion-pair reagent. Cosmetic samples were purified by solid-phase extraction using Bond-Elut SI cartridges. Four acidic preservatives were eluted with methanol from cartridges. The HPLC assay was carried out using TSK gel ODS-80TM column (5 microm, 150 x 4.6 mm I.D.). The mobile phase consisted of a mixture of water and methanol (65:35, v/v) containing 2.5 mM TBA hydroxide adjusted with phosphoric acid to pH 7.0. The calibration curves of these preservatives showed good linearity with UV detection (235 nm). The correlation coefficients were better than 0.999 in all cases. The lower limits of detection (defined as a signal-to-noise ratio of about 3) were approximately 2.5 ng for DHA, 4.0 ng for BA, 2.0 ng for SOA and 5.5 ng for SA. The procedure described here is simple, selective and is suitable for quality control of finished cosmetic products.     

HPLC法测定灰指灵药膏中间苯二酚、水杨酸、苯甲酸的含量

目的：建立灰指灵药膏中间苯二酚、水杨酸、苯甲酸的含量测定方法。方法：采用高效液相色谱法，以C18为固定相，甲醇-磷酸二氢钠(40：60)为流动相，测定波长为254nm。结果：间苯二酚、水杨酸、苯甲酸分别在40．0～200．0μg／mL范围内，其峰面积值与浓度具有良好的线性关系(r=0．9999、0．9997、0．9999)，平均回收率分别为98．1％、97．9％、97．7％。RSD分别为1．88％、1．82％、1．46％。结论：该方法可靠，精密度高，可作为该制剂的质量控制方法。     

Simultaneous determination of procainamide and N-acetylprocainamide in plasma by high-performance liquid chromatography

A sensitive, specific, high-performance liquid chromatographic procedure is described for the simultaneous determination of procainamide and its metabolite, N-acetylprocainamide, in plasma. Basic plasma (2.0 ml), containing pheniramine maleate as an internal standard, is partitioned with methylene dichloride. The organic extract is concentrated to between 0.3 and 0.5 ml, and 100-microliter aliquots are chromatographed on a microparticulate silica gel column using 0.1% acetic acid-20% 0.1 M ammonium acetate in acetonitrile as the mobile phase. With a fixed-wavelength (254-nm) UV detector, both compounds can be quantitated in the 0.1-8.0-microgram/ml of plasma range.     

Simultaneous determination of losartan and hydrochlorothiazide in tablets by high-performance liquid chromatography

A method for the simultaneous determination of losartan potassium and hydrochlorothiazide in tablets is described. The procedure, based on the use of reversed-phase high-performance liquid chromatography, is linear in the concentration range 3.0-7.0 microg ml(-1) for losartan and 0.5-2.0 microg ml(-1) for hydrochlorothiazide, is simple and rapid and allows accurate and precise results. The limit of detection was 0.08 microg ml(-1) for losartan and 0.05 microg ml(-1) for hydrochlorothiazide.     

Simultaneous determination of nitrate and nitrite in toothpastes by high-performance liquid chromatography

A stability-indicating analytical method is described for the simultaneous determination of nitrate, and if present, its reductive degradation product, nitrite, in toothpastes. Nitrate and nitrite were extracted from the toothpaste using distilled water and separated from other water-soluble excipients by two RP-8 columns (250 mm X 4 mm i.d.) using a mobile phase containing 0.2% (w/v) sodium acetate and 2.5% (v/v) glacial acetic acid in distilled water. A UV detector set at 313 nm was used for quantitation. The method was applied to commercial toothpastes containing 5% potassium nitrate and yielded an average recovery of 100.1% with a relative standard deviation of 1.43%. Average recovery of nitrate and nitrite from spiked samples were 100.6% and 96.4%, respectively. The minimum detectable concentration for nitrite was 50 micrograms/g of toothpaste.     

Simultaneous determination of codeine and ibuprofen in plasma by high-performance liquid chromatography

A procedure is described for the simultaneous determination of codeine and ibuprofen in human plasma following the administration of the two substances in a proposed combination dosage form. The two substances were extracted separately from plasma and then determined together by high-performance liquid chromatography (HPLC) using a fluorescence detector. The codeine was first extracted from alkalinized plasma with hexane-dichloromethane (2:1, v/v) and then washed with sodium hydroxide solution. The ibuprofen was then extracted with hexane from the plasma acidified with sulphuric acid. The organic layers were collected, evaporated to dryness and the reconstituted residue was subjected to HPLC. The detection limit for codeine was 8 microg 1(-1) and for ibuprofen 1 mg 1(-1).     

Simultaneous determination of plasma prednisolone, prednisone, and cortisol levels by high-performance liquid chromatography

Recipients of organ transplants remain particularly dependent on prednisolone as part of their maintenance immunosuppression. Despite this, the pharmacokinetics of prednisolone have never been fully characterized in these patients, and consequently dosing remains empirical. Accurate monitoring of prednisolone, its primary metabolite prednisone, and endogenous cortisol suppression in such patients may provide a means of improving the clinical outcome by adjusting for variability in prednisolone pharmacokinetics and pharmacodynamics. Measurement of endogenous cortisol may provide an independent marker of prednisolone pharmacodynamics. A simple isocratic reverse-phase high-performance liquid chromatography procedure, using betamethasone as an internal standard, was developed to quantify plasma prednisolone, prednisone, and cortisol simultaneously. The steroids were extracted from 0.5 mL plasma with 3 mL (1:1 v/v) ethyl acetate/tert-methyl butyl ether and 0.1 mL phosphoric acid, washed in 0.1 mol/L NaOH before a final drying step and reconstitution in mobile phase for injection. Separation was achieved using a Supelcosil LC-18-DB, 150 x 4.6-mm, 5-microm particle size, reverse-phase column attached to a Newguard 15 x 3-mm, RP8 guard column maintained at 25 degreesC, with ultraviolet detector set at 254 nm. The mobile phase consisted of 16% isopropanol in water containing 0.1% trifluoroacetic acid, set at a flow rate of 1.2 mL/min. The assay was linear up to 1,002 microg/L for prednisolone, 982 microg/L for prednisone, and 545 microg/L for cortisol. Mean intra-assay and interassay imprecision levels were 6.0% and 7.2%, respectively, for prednisolone, 5.8% and 7.2% for prednisone, and 5.6% and 7.9% for cortisol. Intra-assay inaccuracy was <7% of nominal values for prednisolone, prednisone, and cortisol. The lower limit of quantification was 7 microg/L for prednisolone and prednisone and 10 microg/L for cortisol. Corticosteroid recoveries were 73%, 74%, and 90% for prednisolone, prednisone, and cortisol, respectively. The authors describe a robust, inexpensive, and simple method suitable for therapeutic drug monitoring or pharmacokinetic studies of prednisolone; it may also be used to measure the suppression of endogenous cortisol production.     

Simultaneous determination of hydrochlorothiazide and triamterene in capsule formulations by high-performance liquid chromatography

A stability-indicating, high-performance liquid chromatographic method is presented for the simultaneous determination of hydrochlorothiazide and triamterene in two-component capsule formulations. An aliquot of the sample is dissolved in a mixture of acetonitrile and aqueous acetic acid, mixed with m-hydroxacetophenone as an internal standard, and chromatographed on octadecylsilane bonded to microparticulate silica using 80% acetate buffer (pH 5.0, 0.004 M)-15% acetonitrile-5% methanol as the mobile phase. The relative standard deviations are +/- 1.1-1.6% for hydrochlorothiazide and +/- 1.7-2.2% for triamterene for two formulations. Recoveries of the two drugs added to placebos ranged from 98.4 to 101.7%.     

Simultaneous determination of cefepime and grepafloxacin in human urine by high-performance liquid chromatography

A liquid chromatographic method with UV detection for simultaneous determination of cefepime and grepafloxacin has been developed. The method uses a C18 column, equipped with a pre-column of the same material, and acetonitrile-0.1 M phosphoric acid/sodium hydroxide buffer (pH 3.0)-0.01 M n-octylamine (pH 3.0) as mobile phase in gradient mode. Mobile flow rate and sample volume injected were 1.3 mL min(-1) and 20 microL, respectively. Detection wavelengths were 259 nm for cefepime and 278 nm for grepafloxacin. The retention times were 4.03 min for cefepime and 8.85 min for grepafloxacin, with detection limits of 1.0 and 1.1 microg mL(-1), respectively. The method was applied to the determination of both antibiotics in spiked samples of human urine.     

Simultaneous determination of amoxicillin and ranitidine in rat plasma by high-performance liquid chromatography

A high-performance liquid chromatography method using ultraviolet detection at 230 nm for the simultaneous determination of amoxicillin and ranitidine in rat plasma has been validated. Plasma samples after pretreatment with acetonitrile to effect deproteinization were dried under N2 and reconstituted with water. The standard calibration curves for amoxicillin and ranitidine were linear (r2=0.9999) over the concentration range of 0.2-20 microg ml-1 and 0.03-6 microg ml-1 in rat plasma, respectively. The intra- and inter-day assay variability range for amoxicillin was 2.4-8.5% and 3.2-11.7%, and for ranitidine was 1.7-9.0% and 4.5-10.1%, respectively. This method has been successfully applied to a pharmacokinetic study after oral coadministration of amoxicillin and ranitidine to rats.