Comparative Study of the Ratio Spectra Derivative Spectrophotometry,Derivative Spectrophotometry and Vierordt's Method Appued to the Analysis of Lisinopril and Hydrochlorothiazide in Tablets

Abstract

Three new spectrophotometric methods are described for the determination of lisinopril and hydrochlorothiazide in their binary mixturer: First derivative spectrophotometry ratio spectra derivative and Vierordt's method. The procedures do not require any prior separation. In the derivative spectrophotometry, the dA/dλ values in the first derivative spectra of the mixture were measured at 269.6 nm for lisinopril and at 279.8 nm for hydrochlorothiazide. The calibration graphs were linear in the range 25.56–129.50 μg.ml^?1 for lisinopril and 10.60–139.80 μg.ml^?1 for hydrochlorothiazide. In ratio spectra derivative spectrophotometry, the calibration graphs for 15.68–129.50 μg.ml^?1 lisinopril and for 5.98–139.80 μg.ml^?1 hydrochlorothiazide were obtained by measuring the signals at 253.7 nm and 243.6 nm for lisinopril and at 280.1 nm and 270.8 nm for hydrochlorothiazide. In Vierordt's method, A¹ ₁ (1 %, 1 cm) values of lisinopril and hydrochlorothiazide were determined at 259.8 nm and 272.7 nm in the zero-order spectra. The quantity of both compounds were calculated by using the A¹ ₁ (1 %, 1cm) values. The methods were successfully applied to a pharmaceutical formulation for determination of both active compounds.     

毛细管电泳法测定非水溶性药物——复方降压片

在区带电泳中,应用在背景电解质中加入乙腈的方法对复方降压片的两种主要成分利血平、双氢氯噻嗪进行了分离和定量测定。５次重复测定的相对标准偏差小于３％,检出限分别为０．２６９ｍｇ／Ｌ和１．８４ｍｇ／Ｌ,并对ｐＨ值、磷酸盐浓度及乙腈用量进行了考察。     

Development and validation of a liquid chromatographic/electrospray ionization mass spectrometric method for the determination of benazepril, benazeprilat and hydrochlorothiazide in human plasma

A new method was developed and fully validated for the quantitation of benazepril, benazeprilat and hydrochlorothiazide in human plasma. Sample pretreatment was achieved by solid-phase extraction (SPE) using Oasis HLB cartridges. The extracts were analysed by high-performance liquid chromatography (HPLC) coupled to a single-quadrupole mass spectrometer (MS) with an electrospray ionization interface. The MS system was operated in selected ion monitoring (SIM) modes. HPLC was performed isocratically on a reversed-phase porous graphitized carbon (PGC) analytical column (2.1 x 125.0 mm i.d., particle size 5 microm). The mobile phase consisted of 55% acetonitrile in water containing 0.3% v/v formic acid and pumped at a flow rate of 0.15 ml min(-1). Chlorthalidone was used as the internal standard (IS) for quantitation. The assay was linear over a concentration range of 5.0-500 ng ml(-1) for all the compounds analysed, with a limit of quantitation of 5 ng ml(-1) for all the compounds. Quality control (QC) samples (5, 10, 100 and 500 ng ml(-1)) in five replicates from three different runs of analyses demonstrated intra-assay precision (coefficient of variation (CV) < or =14.6%), inter-assay precision (CV < or = 5.6%) and overall accuracy (relative error less than -8.0%). The method can be used to quantify benazepril, benazeprilat and hydrochlorothiazide in human plasma, covering a variety of pharmacokinetic or bioequivalence studies.     

基于线性方程组数学分离模型建立光纤传感过程检测复方缬沙坦氢氯噻嗪片溶出度

基于线性方程组数学分离模型建立在线过程检测复方缬沙坦氢氯噻嗪片溶出度方法。分别扫描缬沙坦和氢氯噻嗪的紫外吸收光谱,两组分在最大吸收波长处完全重叠。根据朗伯比尔定律吸光度加和性原理,分别测定两组分在最大吸收波长处的吸光系数,建立线性方程组数学分离模型,采用光纤传感过程分析技术(FODT)检测缬沙坦氢氯噻嗪片的溶出度,并与HPLC法相比较。在规定的溶出介质中,两种成分同时实时测定,并且FODT累积溶出度与HPLC法相比较结果无显著性差异(p>0.05)。不同批次药物的溶出行为一致,说明制剂工艺稳定,均匀度好。溶出曲线显示缬沙坦溶出快于并高于氢氯噻嗪,且30 min时两组分的溶出度均大于80%符合美国药典规定。结果表明,应用线性方程组数学分离模型结合FODT法可实现复方缬沙坦氢氯噻嗪片中双组分溶出度的同时检测,并可提供双组分的溶出过程曲线和全部溶出数据,直观反映各组分在各溶出时段的快慢,为此药建立标准提供依据。与HPLC法单点数据相比优势明显,更有利于药品评价和抽验质量分析。     

Simultaneous Spectrophotometric Determination of Hydrochlorothiazide and Pharmaceutical Preparations

Abstract

We developed three methods for the simultaneous determination of amiloride (AMI) and hydrochlorothiazide (HCT): zero-crossing, derivative quotient spectra with normalized divisor and multiple linear regression (MULTIC) methods. The two first methods use the derivative spectrophotometry, and the last one uses the absorbance measurement. The three methods were used to determine both compounds in synthetic mixtures and pharmaceutical preparations with errors less than 5% and 15%, respectively.     

一阶导数差示脉冲极谱法测定氢氯噻嗪的研究

本研究了一阶导数差示脉冲极谱法用于氢氯噻嗪及其制剂的定量分析。在０．００２ｍｏｌ／Ｌ盐酸－０．００２ｍｏｌ／Ｌ氯化钾底液中，于０．０５０Ｖ（ｖｓ．Ａｇ／ＡｇＣｌ）处出现良好的一阶导数极谱峰，氢氯噻嗪浓度在０～６．０×１０＾－４ｍｏｌ／Ｌ范围内，与峰高呈线性关系，检测限为４．０×１０＾－９ｍｏｌ／Ｌ。方法操作简便、快速、灵敏、结果准确。     

Bioequivalence study between a fixed‐dose single‐pill formulation of nebivolol plus hydrochlorothiazide and separate formulations in healthy subjects using high‐performance liquid chromatography coupled to tandem mass spectrometry

Systemic arterial hypertension is a major risk factor for cerebrovascular disease. Therefore, adequate control of blood pressure is of enormous importance. One of the many fixed‐dose single‐pill antihypertensive formulations available on the market is the combination of nebivolol and hydrochlorothiazide. The objective of this study was to develop two distinct high‐performance liquid chromatography coupled to tandem mass spectrometry methods to simultaneously quantify nebivolol and hydrochlorothiazide in human plasma. The methods were employed in a bioequivalence study, the first assay involving a nebivolol fixed‐dose single‐pill formulation based on healthy Brazilian volunteers. Nebilet HCT™ (nebivolol 5 mg + hydrochlorothiazide 12.5 mg tablet, manufactured by Menarini) was the test formulation. The reference formulations were Nebilet™ (nebivolol 5 mg tablet, manufactured by Menarini) and Clorana™ (hydrochlorothiazide 25 mg tablet, manufactured by Sanofi). For both analytes, liquid–liquid extraction was employed for sample preparation and the chromatographic run time was 3.5 min. The limits of quantification validated were 0.02 ng/mL for nebivolol and 1 ng/mL for hydrochlorothiazide. Since the 90% CI for C _max, AUC_(0–last) and AUC_(0–inf) individual test/reference ratios were within the 80–125% interval indicative of bioequivalence, it was concluded that Nebilet HCT™ is bioequivalent to Nebilet™ and Clorana™.     

Simultaneous determination of olmesartan medoxomil and irbesartan and hydrochlorothiazide in pharmaceutical formulations and human serum using high performance liquid chromatography

 A simple, selective, sensitive, precise, simultaneous high performance liquid chromatographic analysis of serum samples and commercial tablet formulation containing hydrochlorothiazide, olmesartan medoxomil and irbesartan are reported. Good chromatographic separation was achieved using a μ-Bondapak, C18 column (15 cm×4.6 mm, 5 μm), and a mobile phase consisting of acetonitrile-0.2% acetic acid aqueous solution (50∶50, v/v) at a flow rate of 1.0 mL/min. The ultraviolet detector was set at a wavelength of 260 nm. Hydrochlorothiazide, olmesartan medoxomil, and irbesartan were eluted at 1.2, 3.8, and 4.4 min, respectively. No extraneous materials were found to interfere. The method uses protein precipitation with acetonitrile for the preparation of serum sample. The linear ranges for hydrochlorothiazide, olmesartan medoxomil, and irbesartan were 6.25-18.75, 20-60, and 75-225 ng/mL, respectively. The recoveries of hydrochlorothiazide, olmesartan medoxomil, and irbesartan in spiked samples were all greater than 98%, and their relative standard deviations were less than 2.0%. The limits of detection were 1, 2, and 2 ng/mL for hydrochlorothiazide, olmesartan medoxomil, and irbesartan, respectively, and the limits of quantification were 3 ng/mL, which allow their determination at the expected serum concentration levels.     

Sensitive liquid chromatography-tandem mass spectrometry method for quantification of hydrochlorothiazide in human plasma

A simple, rapid, sensitive and specific liquid chromatography-tandem mass spectrometry method was developed and validated for quantification of hydrochlorothiazide (I), a common diuretic and anti-hypertensive agent. The analyte and internal standard, tamsulosin (II) were extracted by liquid-liquid extraction with diethyl ether-dichloromethane (70:30, v/v) using a Glas-Col Multi-Pulse Vortexer. The chromatographic separation was performed on a reversed-phase column (Waters symmetry C18) with a mobile phase of 10 mm ammonium acetate-methanol (15:85, v/v). The protonated analyte was quantitated in negative ionization by multiple reaction monitoring with a mass spectrometer. The mass transitions m/z 296.1 solidus in circle 205.0 and m/z 407.2 solidus in circle 184.9 were used to measure I and II, respectively. The assay exhibited a linear dynamic range of 0.5-200 ng/mL for hydrochlorothiazide in human plasma. The lower limit of quantitation was 500 pg/mL, with a relative standard deviation of less than 9%. Acceptable precision and accuracy were obtained for concentrations over the standard curve ranges. A run time of 2.5 min for each sample made it possible to analyze a throughput of more than 400 human plasma samples per day. The validated method has been successfully used to analyze human plasma samples for application in pharmacokinetic, bioavailability or bioequivalence studies.