Determination of pravastatin by high performance liquid chromatography

BACKGROUND: Pravastatin is a hydrophilic liver-specific inhibitor of the enzyme 3-hydroxy-3-methylglutaryl coenzyme A reductase. It effectively lowers plasma cholesterol and low-density lipoprotein concentrations in humans. Pharmacokinetic studies of pravastatin have been mostly performed by means of radioactively labelled drug or by measuring plasma concentrations with gas chromatography and mass spectrometry. AIMS OF THE STUDY: Aim of our study was to develop a simple, but reliable method which allows the determination of pravastatin plasma concentrations under clinical routine conditions. SUBJECTS, MATERIALS AND METHODS: Samples were prepared by solid-phase extraction on cyclohexyl bond elut cartridges. Chromatography was carried out on an octyl matrix. Triamcinolone acetonide was used as internal standard. The method was linear within the range of 5 to 200 microg/l pravastatin. The coefficient of variation depended on the pravastatin concentration, but was less than 10% throughout. The pharmacokinetics of pravastatin were determined in healthy individuals. Five healthy subjects received single oral doses of pravastatin (60 mg) and one of these subjects additionally received a dose of 80 mg at three different study days. In all subjects blood was sampled 0, 30, 60, 90, 120, 150, 180, 240 and 300 min after drug intake. RESULTS: Peak plasma concentrations of pravastatin were found between 60 min and 120 min after oral administration of 60 mg and reached values between 37 microg/l and 126 microg/l. The calculated AUCs were between 52 ng/ml x h and 311 ng/ml x h and the corresponding plasma elimination half-life times were between 95 min and 165 min. In all subjects plasma concentrations of pravastatin 5 hours after oral drug administration were near the detection limit of the method (5 microg/l). Intraindividually, there was only little variation in the kinetics of pravastatin. However, marked differences were encountered between the subjects studied. CONCLUSION: The data suggest that the determination of pravastatin plasma concentrations by means of a HPLC system can be used for routine analysis of pravastatin plasma concentrations. The obtained pharmacokinetic data in healthy individuals stand in ample agreement with the results of prior studies in which the concentrations of pravastatin were determined by other more sophisticated methods.     

高效液相色谱法测定莫西沙星制剂含量

目的 :建立高效液相色谱法测定莫西沙星制剂的含量。方法 :采用InertsilODS 2色谱柱 (5 μm ,2 5 0mm× 4.0mm) ,流动相为 1%三乙胺溶液 (磷酸调pH值至 4.5 )—乙腈 (84∶16,v/v) ;柱温 :40℃ ;检测波长 :2 96nm ;流速 :1.0ml/min。结果 :线性范围 0 .4～ 3 μg ,r =0 .9999,平均回收率为 10 0 .7% (RSD =0 .7% )。结论 :方法简单 ,专属性好 ,可用于莫西沙星制剂的含量测定。     

高效液相色谱法测定三磷酸腺苷二钠含量

目的建立三磷酸腺苷二钠含量的测定方法。方法采用高效液相色谱法 ,以弱碱性离子交换球状硅胶为固定相 ;检测波长 2 5 9nm ;流动相为磷酸盐缓冲液 (pH 7.0 ) ;柱温 35℃。结果此法可将三磷酸腺苷二钠与一磷酸腺苷、二磷酸腺苷二钠盐分离。结论该法专属性强 ,灵敏、快速     

高效液相色谱法测定马拉韦罗片的含量

目的建立高效液相色谱法测定马拉韦罗片的含量。方法色谱柱:Shimadzu C18柱(250 mm×4.6 mm,5μm),流动相:乙腈-0.01 mol.L-1磷酸二氢钾溶液(25∶75,V/V),柱温:(35.0±1.0)℃,流速:1.0 mL.min-1,检测波长:197 nm。结果马拉韦罗的线性范围为0.1～0.5 g.L-1(r=0.999 7),平均回收率为(99.83±0.60)%(n=9)。结论本方法简便、准确,可用于马拉韦罗片的含量测定。     

HPLC法测定淫羊藿苷微乳的含量

目的 建立高效液相色谱法测定淫羊藿苷微乳的含量.方法 采用色谱柱:ASMKromasil C18(150 mm×4.6 mm,5μm);流动相:乙腈-水(体积比30∶70:):流速:1.0 ml·min-1;检测波长:270 nm;柱温:25℃.结果 淫羊藿苷在0.55～1.45μg范围内的线性关系良好,r=0.9996.加样回收率为99.12％,RSD为0.32％.结论 本测定方法快捷、简便、准确,可用于淫羊藿苷微乳的质量控制.     

高效液相色谱法测定血浆中法莫替丁的浓度

目的:用高效液相色谱法测定血浆中法莫替丁浓度。方法:以对乙酰氨基酚为内标,血浆经乙腈提取,HPLC测定。流动相0.01m o l.L-1磷酸二氢钾-乙腈(91.5:8.5),流速1.0m l.m in-1,C 18色谱柱A lltech A po llo(4.6mm×150mm),检测波长266nm。结果:法莫替丁和内标与内源性杂质分离良好;5~160 ng.m-l 1浓度范围内线性关系良好;检测限2.5 ng.m-l 1;日内精密度RSD为1.5%~6.7%(n=6),日间精密度RSD为0.2%~14%(n=6)。结论:本法简便、灵敏度较好,可用于法莫替丁血药浓度的测定。     

反相高效液相色谱法测定盐酸乙哌立松片剂的含量

目的：建立高效液相色谱法测定盐酸乙哌立公片含量的方法。方法：酸盐乙哌立松片加甲醇,超声振荡,过滤后以ODS C18为分析柱,以甲醇－水－三乙胺（80：19．5：0．5,V／V）为流动相,托哌酮为内标,于254nm波长检测。结果：盐酸乙哌立松在0．4－1．6mg/ml浓度范围内线性关系良好（r=0.9999),平均回收率98．4％,RSD,1．2％,三批协酸乙哌立松片含量测定结果分别为标示量的97．8％,98．3％和98．9％,结论：方法快速,准确,专一性强,适用于盐酸乙哌立松片的含量测定。     

高效液相色谱法测定米非司酮的血药浓度

目的　建立测定米非司酮血药浓度的方法。方法　以乙腈∶水 (70∶3 0 )为流动相 ,炔诺酮作内标 ,血浆样品经用乙醚萃取后上样 ,经C18柱分离后 ,在紫外波长 3 0 2nm处检测米非司酮 ,在 2 40nm处检测炔诺酮。结果　线性范围 0 .0 5～ 10 .0 μg·mL-1(r =0 .9995 )。平均相对回收率在 95 %～ 110 %之间 ,日内和日间RSD均小于 6%。米非司酮最低检出限为 0 .0 1μg·mL-1,萃取回收率大于 90 %。结论　本法快速、简便、准确、灵敏 ,可用于米非司酮的药物动力学研究     

Determination of clonazepam in serum by high performance liquid chromatography

A simple, specific, and sensitive high-performance liquid chromatography (HPLC) method has been developed for the routine monitoring in serum of the benzodiazepine anticonvulsant, clonazepam. Serum spiked with internal standard, methylclonazepam, was vortex-mixed for 1 min with chloroform at an alkaline pH. The evaporated extract was dissolved in the HPLC mobile phase consisting of sodium phosphate buffer, acetonitrile, and methanol. Analytics were resolved at ambient temperature on a 5-micron Supelcosil LC-PCN column (150 X 4.6 mm) equipped with a guard column. Flow rate was 2.0 ml/min, and monitoring was at 306 nm. The calibration curve was linear from 2 to 200 ng/ml. This method provides selectivity and sensitivity with a precision of 3.5%, average recovery of 99%, and no interference from 42 commonly administered drugs.     

用高效液相色谱法测定兔血清中硫酸庆大霉素的含量

本文以高效液相色谱法测定血清中硫酸庆大霉素的含量。加内标物茴香胺。乙腈沉淀蛋白质等干扰物，室温下进行邻苯二醛衍生化，醋酸乙酯提取后进样，用紫外３３０ｎｍ检测。     

苯磺酸氨氯地平胶囊的高效液相色谱法测定

目的:建立高效液相色谱法测定苯磺酸氨氯地平胶囊含量,为质量控制提供有效的分析手段.方法:色谱柱:Phenomenex ODS C18( 5μm、4.6mm ×150mm);流动相:甲醇-0.03mol·L-1磷酸二氢钾溶液(65:35);检测波长:2 39nm.结果:制剂中辅料和有关物质对主药无干扰,苯磺酸氨氯地平在浓度9.952～99.520μg·ml-1范围内线性关系良好,相关系数r＝0.9999(n=6);平均回收率分别为99.09%、100.4%、101.2%,RSD为0.12%.结论:本法专属性好,准确,简便.杂质,可有效控制本品质量.     

Determination of yohimbine in serum by high performance liquid chromatography

An automated method for determination of yohimbine (Yoh) in the serum was developed by means of column switching high performance liquid chromatography (HPLC). TSK-precolumn BSA-ODS and TSK-gel ODS-120T were used as a precolumn and analytical column, respectively. The wavelengths of detection were used at 280 nm (excitation) and 360 nm (emission). A 100 microliter serum sample is directly injected onto the precolumn. Yoh is then eluted within 30 min with an methanol-potassium phosphate buffer mixture. The analytical recoveries (99.3-110.4%), reproducibilities (within-run, C.V. less than 2.27%), and detection limit (0.80 ng/ml, S/N = 3) indicate that this system is suited for determination of Yoh. The five healthy volunteers received a single oral dose 10 mg of HYoh powder. The average of the maximal serum concentration and the area under the curve (AUC) from 0 to 4 h were 10.3 +/- 0.88 ng/ml and 19.70 +/- 0.87 ng.h.ml-1, respectively. The elimination rate constant (Kc1) was 0.52 +/- 0.03 h, and biological half-life (t1/2el) was 1.32 +/- 0.12 h.     

HPLC法测定复方地塞米松乳膏中地塞米松的含量

复方地塞米松乳膏是由地塞米松、薄荷脑及樟脑制成的外用制剂,具有抗炎、抗过敏、止痒、抑制角化异常等作用,主要用于治疗各种类型的湿疹和皮炎[1].由于复方地塞米松乳膏中主药含量低,基质干扰严重,紫外分光光度法难以进行分离和测定,计算分光光度法又存在基质成分复杂、组分质量时有差异,致使测定结果误差较大等问题[2,3].因此本研究建立了一种快速、简便、专属性较强的测定乳膏中地塞米松含量的HPLC方法,适用于含地塞米松制剂的含量测定.     

高效液相色谱法测定瑞巴匹特血浆浓度

目的 :建立测定血浆内瑞巴匹特浓度的高效液相色谱法。方法 :KromasilC18色谱柱 ,甲醇 -0 .0 5mol·L- 1磷酸二氢钾 (55∶45,pH3.0 )为流动相 ,并由序贯单纯形法确定此为最佳配比点 ,流速 1 .0ml·min- 1,检测波长 2 30nm。结果 :瑞巴匹特在 1 5～ 1 2 0 0 μg·L- 1范围内 ,血浆药物浓度C与色谱峰高H呈现良好线性相关 ,血浆中瑞巴匹特平均相对回收率为(97.5± 0 .5) %(n =5) ,平均绝对回收率为 (90 .3± 1 .8) %(n =5) ;平均日内和日间RSD分别为 4.6 8%和 5.6 6 %(n =5) ;方法对血浆瑞巴匹特最低检出浓度为 2 μg·L- 1。结论 :本方法适于血浆中瑞巴匹特的测定。     

Determination of leflunomide in tablets by high performance liquid chromatography

In the present study, a reverse phase high performance liquid chromatography (HPLC) method was validated and applied for the determination of leflunomide in tablets. Chromatographic separation of leflunomide and oxazepam as an internal standard was carried out on a C(18) column (50 mm, 3 mm i.d.) using a mobile phase, consisting of methanol and water (60:40, v/v), at a flow rate of 0.5 ml min(-1) and UV detection at 260 nm. The retention times for oxazepam and leflunomide were 2.6 and 5.2 min, respectively. The validated quantification range of the method was 2.7 x 10(-6) to 5.5 x 10(-5) M for leflunomide. The results of the developed procedure in tablets were compared with those of UV spectrophotometry to assess active leflunomide content.     

高效液相色谱法测定交沙霉素血药浓度

目的建立测定人体内血清中交沙霉素(Jos)浓度的方法.方法采用改进的HPLC法,色谱柱为SUPELCODiscovery     

氯沙坦钾片的HPLC测定

目的:建立高效液相色谱法测定氯沙坦钾片含量,为质量控制提供有效的分析手段.方法:色谱柱:Phenomenex ODS C18(5μm、4.6mm×150mm);流动相:乙腈-0.1%磷酸溶液(55:45);检测波长:230nm.结果:制剂中辅料和有关物质对主药无干扰,氯沙坦钾在浓度100.2～350.8μg/mL范围内线性关系良好,相关系数r＝0.9999;平均回收率分别为99.36%、99.68%、99.40%,RSD为0.42%.结论:本法专属性好,准确,简便.     

高效液相色谱法分析胸苷衍生物BOC-FLT含量

目的:建立一种HPLC法分析正电子发射断层(PET)肿瘤诊断药物18F-FLT标记前体BOC-FLT的含量,为药盒质量控制提供有效的检测手段。方法:乙腈作为溶剂,235nm作为检测波长,乙腈-水(85∶15)作流动相,HPLC法分析BOC-FLT含量。结果:主峰保留时间为6.6min,杂质峰保留时间为4.5min,分离度大于1.5,BOC-FLT在100~500mg.L-1试验范围内呈良好的线性关系,回归方程为y=3E+06x-301 953,R2=0.999 5。FLT-BOC最小检出量为2.5ng(S/N≥3);杂质最小检出量为1.2ng(S/N≥3)。结论:方法简便、可靠,重复性好,能够为药盒的质量控制提供有效的分析手段。     

去甲斑蝥素片的高效液相色谱质量检测

目的 研究去甲斑蝥素片的质量控制方法。方法采用HPLC法,色谱柱Polarls C_(18)柱(5 μ,4.6mm×250mm),检测波长为211 um,流动相为:水:乙醇(85:15),以磷酸调节pH至3.1。结果 去甲斑蝥素在25～1000mg·L~(-1)范围内呈线性系统,r=0.9 999,最低检出限为0.2mg·L~(-1),平均回收率为100.84％,平均RSD为1.335％。结论 该方法快速、准确,重现性好,适用于该制剂的含量测定。