A Simultaneous Analysis by High Performance Liquid Chromatography of Bamipine Combined with Tricyclic Antidepressants and/or Antipsychotics in Dosage Forms

Abstract

A reversed phase high-performance liquid chromatographic method is described for the simultaneous determination of antihistamines, tricyclic antidepressants and anti-psychotics in pharmaceutical formulations and in spiked placebos. The separation was performed on an octadecyl-silica column using acetonitrile: tetrahydrofuran: 0.015 M aqueous ammonium acetate (53:42: 5) as mobile phase. The presence of ammonium acetate both shortens the elution time and improves the symmetry of the chromatographic peaks. Measurements were made at 251 nm.     

液相色谱法测定血浆中三环类抗忧郁药物

用高效液相色谱法测定了血浆中４种三环类抗忧郁药物：卡马西平、氯氮平、多虑平和阿米替林。方法采用Ｃ_（１８）色谱柱分离,二极管阵列检测器检测,流动相为甲醇：０．５ｍｏｌ／Ｌ三乙胺－０．５ｍｏｌ／Ｌ冰醋酸的水溶液（９０：１０,Ｖ／Ｖ;ｐＨ７．５）。标准曲线的线性范围为０～１０ｍｇ／Ｌ,相关系数在０．９９以上。方法的最小检出浓度为１０～４０μｇ／Ｌ血浆。血中药物经溶剂萃取后,药物的回收率为７３．６７％～９８．２４％,血中杂质不影响药物的检测。方法简便、快速,适用于临床中毒样品的分析。     

Reversed Phase High - Performance Liquid Chromatographic Analysis of Tricyclic Antidepressants in Plasma

Abstract

A reversed phase HPLC procedure is described for measuring the plasma concentration of four commonly used tricyclic anti-depressants (TCA): amitriptyline, desipramine, imipramine and nortriptyline in the range of 25 to 800ng per ml. The procedure involves rapid extraction, and HPLC analysis using a μBondapak C-18 column at 50°C, and a 254nm detector. Coefficients of variation are less than 5% for within run, and 7% for day-to-day experiments. Detection limits are: desipramine -0.5ng, nortriptyline or imipramine -0.6ng, and amitriptyline -0.7ng. Propoxyphene interferes with amitriptyline while chlorpromazine interferes with clomipramine. The procedure is easily adapted for clinical drug monitoring of TCA.     

High Performance Liquid Chromatographic Analysis of Rifampin and Related Impurities in Pharmaceutical Formulations

Abstract

High pressure liquid chromatography was employed for the assay of rifampin in capsules. A reverse phase RP-2 column and a mobile phase of 48% methanol, 5% tetrahydrofuran and 47% 0.05 M ammonium formate (pH 7.3) were used with detection at 254 nm. Rifampin was separated from all its major degradation products and quantitated.     

Determination of Reserpine in Pharmaceutical Formulations by High Performance Liquid Chromatography

Abstract

High performance liquid chromatography was employed in the assay of reserpine in tablet formulations. A reverse-phase RP-8 column was used and reserpine was separated from its major degradation products and quantitated by peak-height measurement using ultraviolet detection at 254 nm and fluorescence at 330 nm excitation. Tablets analysed were within the official limits even after more than ten years following manufacture.     

High Performance Liquid Chromatographic Determination of Flurbiprofen in Pharmaceutical Dosage Forms

Abstract

A rapid, specific and reliable high performance liquid chromatographic assay of flurbiprofen in dosage forms has been developed. Reversed-phase chromatography was conducted using a mobile phase of 0.05 M ammonium acetate and acetonitrile, (40% v/v) PH 5.2 and detection at λ 247 nm. The recovery and coefficient of variation from six placebo tablets spiked with 100 mg of flurbiprofen were 100.1% and 0.4% respectively. Replicate regression analyses of three standard plots in the concentration range 0.5 - 9 mcg/ml obtained on three different days gave a correlation coefficient (0.99996) and the coefficient of variation of the slopes 0.159%. The assay was precise within day and between days as indicated by ANOVA test. It is suggested that the proposed HPLC method should be used for routine quality control and dosage form assay of flurbiprofen.     

Reverse-Phase High Performance Liquid Chromatographic Determination of Clidinium Bromide and Chlordiazepoxide in Tablet Formulations

Abstract

Clidinium bromide is a quaternary ammonium anticholinergic agent with peripheral effects. It is commercially available in combination with chlordiazepoxide. There is no official compendial method available for the analysis of both compounds concurrently. Conventional methods for determining both compounds involve extensive extraction and thus are time-consuming, and lack precision. The analytical scheme described in this paper provides a fast and reliable reverse-phase HPLC for chlordiazepoxide and clidinium bromide in pharmaceutical combinations. The mobile phase was 0.04 M ammonium acetate in 70% acetonitrile solution with 1% dimethylformamide (pH 6). The column was microPak MCH-10 (300.0 mm × 4.0 mm), UV detection at 254 nm and benzophenone was used as internal standard. The method was confirmed for linearity, recovery, specificity, accuracy, and applicability.     

High Performance Liquid Chromatographic Determination of Pirenzepine Dihydrochloride in Its Pharmaceutical Formulation

Abstract

A high-performance liquid chromatographic procedure for the determination of pirenzepine dihydrochloride as a bulk material and in its tablet dosage form (Gastrozepin^R) is presented. Normal phase liquid chromatography has been performed on a Micro-pack Si-10 column using ammonium hydroxide (28–30% NH₃) in methanol (0.75: 99.25% v/v) as mobile phase at a flow rate of 2 ml/min. Clobazam has been used as internal standard with retention times of 1.9 and 2.8 minutes for clobazam and pirenzepine dihydrochloride, respectively at 254 nm. Analytical calibration yields a linear relationship between 5 and 25 μg/ml, with correlation coefficient of 0.999. Tablets each labelled to contain 25 mg pirenzepine dihydrochloride give mean percentage found of 99.98 ± 0.4. A plot of logarithm of concentration against time for a solution in 6 N hydrochloric acid gives a straight line with a slope of - 0.197 day^?1. The proposed method is, therefore, a stability indicating method.     

Simultaneous High Performance Liquid Chromatographic Determination of Amitriptyline Hydrochloride and Perphenazine in Tablet Formulations

Abstract

A rapid, precise, and accurate high performance liquid chromatographic procedure is presented for the simultaneous determination of amitriptyline hydrochloride and perphenazine in two component tablet formulations. The related compounds of amitriptyline hydrochloride were separated, making the determination specific for amitriptyline hydrochloride and perphenazine. The method was used for the assay and content uniformity for three commercial products. The mobile phase was 0.02 M ammonium acetate in aceto-nitrile: methanol: water (45:15:40) solution and the pH was adjusted to 5.0 by acetic acid. The column was a supelcosil (5 μm) LC-8-DB (250 mm × 4.6 mm i. d). The method was tested for linearity, recovery, and specificity.     

A Simple Liquid Chromatographic Method for the Simultaneous Determination of Antidepressants in Pharmaceutical Preparations

Fluoxetine (FT), fluvoxamine (FX), sertraline (ST) and trazodone (TD) are new type of antidepressants acting as selective serotonin reuptake inhibitors (SSRIs). In structures, they all have chromophore and can be easily monitored by UV absorption spectrophotometry. A simple isocratic high‐performance liquid chromatographic method with ultraviolet detection (215 nm) was developed for the simultaneous quantification of FT, FX, ST and TD. The determination range of the method is over 10.0–400.0 μM for each drug. The detection limits (S/N = 3, injection 20 μL) are about 0.1 μM for TD, 0.2 μM for FT, FX and ST. The relative standard deviation and relative error of the method for intra‐ and inter‐day analyses of FT, FX, ST and TD were all below 3.7%. Application of the method to the analysis of FT, FX or ST in pharmaceutical product proved feasible. The method could be used for the quality control assay of the analytes in bulk and in formulations.     

Specific and Sensitive High Performance Liquid Chromatographic Determination of Alprazolam or Triazolam

Abstract

A specific and highly sensitive liquid chromatographic procedure has been developed for the rapid determination of intact alprazolam or triazolam in dog serum, using these structurally similar triazolobenzodiazepines as mutual internal standards. The procedure consists of (1) extracting one ml of alkali buffered serum with toluene, (2) evaporating an aliquot of the toluene to dryness, and (3) quantitating the redissolved residue by HPLC using ultraviolet detection (221 nm). Samples were chromatographed on a microparticulate reverse phase column using a mobile phase composed of acetonitrile: isopropanol: water (94:5:1) and a flow rate of 0.75 ml/min. Metabolites of alprazolam and triazolam did not interfere in the assay. The lower limit of detection was approximately 1 ng/ml of serum extracted. The utility of the analytical methodology for the determination of alprazolam or triazolam in pharmacokinetic studies in the dog was demonstrated.     

High Performance Liquid Chromatographic Assay of phenylbutazone in Pharmaceutical Dosage Forms

Abstract

A simple, rapid and reliable high performance liquid chromatographic procedure for the quantitation of phenylbutazone in pharmaceutical dosage forms was developed, and compared with the U. S. P. XXI method and a spectrophotometric assay developed in this laboratory. A comparison of the three methods indicated that the HPLC method is the most rapid, simple and reproducible. The recoveries based on six placebo samples were 100.2, 99.2, and 99.4% by HPLC, UV and the U. S. P. method, respectively, and their respective CVs were 0.39, 0.73, and 1.5%. Replicate regression analyses of three standard plots in the concentration range of 0.02-0.12 mg/ml obtained using the HPLC assay on three different days yielded a correlation coefficient <0.999 and the coefficient of variation for the three slopes was 1.05%. It is suggested that the proposed HPLC method should be used for routine quality control and dosage form assay of phenylbutazone.     

High Performance Liquid Chromatographic Determination of Pentamidine in Plasma

Abstract

A high performance liquid chromatographic method for quantitating pentamidine in plasma has been developed. Sample clean-up involved precipitating plasma with acetonitrile containing the internal standard, hexamidine. The supernatant was passed through a C₈ Bond Elut column and eluted with a methanolic solution of sodium 1-heptanesulfonate. The eluate was then analyzed on an Altex C₈ column with a mobile phase consisting of 45% CH₈CN, 0.02% detramethylammonium chloride and 0.1% H₃PO₄. Using fluorescence detection (EX: 275 nm and EM: 340 nm), the detection limit was 1.25 ng/ml for 0.5 ml of plasma. The coefficients of variation for interday and intraday were around 10%.     

High Pressure Liquid Chromatographic Determination of Parabens in Pharmaceutical Preparations Containing Hydroxyquinolines

Abstract

A high pressure liquid chromatographic (HPLC) procedure for the analysis of methyl paraben (MP) and propyl paraben (PP) in pharmaceutical preparations containing a halogenated hydroxyquinoline (HHQ) is described. The method involves a separation of the phenolic constituents, MP, PP and HHQ with a Bio-Rad AG 1–X8 anion exchange resin, elution of the phenols with methanol after acidification and a reverse phase HPLC separation of the parabens using methanol-pH 6.5 buffer (60/40) mobile phase, a 30 cm × 3.9 mm (i.d.) column packed with Waters μBondapak C₁₈ packing and a guard column packed with Waters Bondapak C₁₈/Corasil packing. Recovery, precision, specificity and interference data along with the application of the proposed method for some commercial formulations both with and without a hydroxyquinoline are described.     

High-Performance Liquid Chromatographic Method for the Simultaneous Determination of Four Flavonols in Food Supplements and Pharmaceutical Formulations

A method using high-performance liquid chromatography with diode array detection (HPLC-DAD) as a powerful separation technique has been developed for the simultaneous determination of the four flavonols rutin, quercetin, kaempferol and isorhamnetin in food supplements and pharmaceutical formulations. The chromatographic separation was achieved in 36?min using a Symmetry C₁₈ column (250?×?3?mm; 5?µm) as the stationary phase and a mixture of methanol, acetonitrile, and pH 2.5 aqueous acetic acid as the mobile phase in gradient elution mode. The analytical wavelengths were 256?nm for rutin, quercetin and isorhamnetin, and 368?nm for kaempferol. An ultrasound-assisted extraction protocol was performed using methanol as solvent. The detection and quantification limits were lower than 0.03?µg mL^?1 and 0.08?µg mL^?1, respectively. The inter-day and intra-day precisions were less than 4.8 and 5.1%, respectively, and the average recoveries were in the range from 96 to 107%. The method was applied for the determination of the studied flavonols in food supplements and pharmaceutical preparations. The satisfactory recovery values demonstrate the potential of the developed method for the determination of the analytes in these samples. In addition, the method is suitable for routine quality control due its ease of operation.     

High Performance Liquid Chromatographic Determination of Oxamniquine in Plasma Samples

Abstract

A sensitive and reliable liquid chromatographic assay procedure for the quantitation of oxamniquine in plasma or urine was developed. Chromatographic separation was achieved on a reversed-phase phenyl colum using U.V. Detection at 254 nm. The eluting solvent was the mixture of 0.05 M acetate buffer pH 5 and acetonitrile (3:7). With this mobile phase the drug and its external standard were well separated from the interference of the blank samples. The average recovery of oxamniquine from 3 or more replicate dog plasma samples of different concentration (0.125 ? 4.00 μg/ml) was 95.5% and its coefficient of variation was 4.17%. The reproducibility of the assay was confirmed by the analysis of variance test for the slopes of the three standard plots obtained from plasma samples at three different occasions (F=4.2, p > 0.01). The detection limit for plasma samples was approximately 20 ng/ml. The method was applied to measure the plasma level vs, time profile of this drug following a single bolus intravenous dose of 16 mg/kg to a dog.     

High Performance Liquid Chromatographic Determination of Triazolam in Human Serum

Abstract

A high performance liquid chromatographic method which utilizes UV-detection has been developed for the sensitive and specific determination of triazolam in human serum. Using 8-chloro-6-phenyl-l-ethoxymethyl-4H-s-triazolo[4, 3-a][1, 4]benzodiazepine as an internal standard, serum samples were buffered with 2 ml of 4M NaOH and extracted twice with 5 ml aliquots of toluene. The combined toluene extracts were evaporated to dryness and the residue dissolved in the chromatographic mobile phase. The samples were chromatography on a microparticulate reverse-phase column using a 0.06M acetic acid:acetonitrile (61:39) mobile phase. Known metabolites of triazolam did not interfere in the analysis. A linear relationship between peak height ratios and concentrations was observed, with the lower limit of detection being approximately 1 ng of triazolam. The utility of the method was demonstrated by administering therapeutic doses of the drug to human volunteers and monitoring serum triazolam concentrations as a function of time.     

High Performance Liquid Chromatographic Determination of Amiodarone in Plasma and Tissues

Abstract

A simple and rapid high-performance liquid chromatographic (HPLC) method for the determination of amiodarone (AD) in plasma and tissues was developed. The method involved deproteinization of plasma or homogenized tissue with acetonitrile containing an internal standard (N-Cetylpyridinium chloride) followed by reversed phase chromatography using μ bondapack C₁₈ column (10μm) with a mobile phase consisting of acetonitrile - methanol - sodium dihydrogen phosphate buffer (70:10:20%, v/v), the pH adjusted to 4.0 and pumped at flow rate of 1.0 ml/min. The column effluent was monitored at 242 nm. A linear relationship was obtained between peak height ratios (drug to internal standard) versus drug levels over the concentration range of 50–750 ng/ml. The detection limit of AD in plasma and tissues by this method was 20 ng/ml.     

A Stability Indicating High Performance Liquid Chromatographic Assay of Isradipine in Pharmaceutical Preparations

Abstract

A high performance liquid chromatographic procedure has been developed for the assay of isradipine in bulk form and tablet and capsule pharmaceutical preparations. The separation is achieved within 20 min on an octadecylsilane column at ambient temperature with a mobile phase of 60:40 v/v methanol - water, a flow rate of 1 mL/min, and detection at 325 nm. Degradation studies showed no peak interference between isradipine and degradation products. It was also determined that the excipients in the commercial tablet and capsule preparations did not interfere with the assay. The method was linear in the range 10–60 μg/mL with accuracy and precision in the 0.40 - 1.53% range.     

高效液相色谱法测定贝类中的软骨藻酸

 介绍了用反相高效液相色谱 (RP HPLC)测定贝类中软骨藻酸的方法。样品以V(甲醇 )∶V(水 ) =1∶1的溶液提取 ,经LC SAX强阴离子柱固相萃取净化 ,用RP HPLC定量分析。方法的最小检出限为 0 2 μg/ g ,在 1 0mg/L～ 2 5 0mg/L范围内有良好的线性关系 ,测定结果准确 ,重现性好 ,回收率大于 96 %。