Simultaneous determination of triamterene and hydrochlorothiazide in tablets using derivative spectrophotometry

A quick and accurate method for determining triamterene and hydrochlorothiazide in complex drugs of diuretic activity by using first-derivative (D1) and second-derivative (D2) spectrophotometry was developed. The zero-crossing technique was employed in measurements, using D1 at lambda = 240.9 nm and D2 at lambda= 278.2 nm for determining triamterene and D1 at lambda = 255.7 nm and D2 at lambda = 283.2 nm for hydrochlorothiazide. The linear relationship between the values of derivatives and analyte concentrations are maintained for concentrations from 2.40 microg x mL(-1) to 12.00 microg x mL(-1) for triamterene and from 1.25 microg x mL(-1) to 6.25 microg x mL(-1) for hydrochlorothiazide. LOD for triamterene was 0.90 microg x mL(-1) or 1.02 microg x mL(-1), while LOQ was 2.73 microg x mL(-1) or 3.08 microg x mL(-1). The corresponding values for hydrochlorothiazide were: LOD 0.25 microg x mL(-1) or 0.17 microg x mL(-1) and LOQ 0.77 microg x mL(-1) or 0.51 microg x mL(-1) depending on the derivative used. The determination results of drug constituents are of high accuracy, percentage recovery ranging from 97.17% to 99.74% for triamterene and from 102.44% to 102.64% for hydrochlorothiazide, and good precision. The computed values of RSD are smaller than 2.73% for triamterene and below 1.63% for hydrochlorothiazide. Selectivity and sensitivity of the developed method are satisfactory.     

Simultaneous determination of benazepril hydrochloride and hydrochlorothiazide by micro-bore liquid chromatography

A micro-bore liquid chromatographic method was developed for the simultaneous determination of benazepril hydrochloride and hydrochlorothiazide in pharmaceutical dosage forms. The use of a BDS C-18 micro-bore analytical column, results in substantial reduction in solvent consumption and increased sensitivity. The mobile phase consisted of a mixture of 0.025 M sodium dihydrogen phosphate (pH 4.8) and acetonitrile (55:45, v/v), pumped at a flow rate of 0.40 ml min(-1). Detection was set at 250 nm using an ultraviolet detector. Calibration graphs are linear (r better than 0.9991, n = 5), in concentration range 5.0-20.0 microg ml(-1) for benazepril hydrochloride and 6.2-25.0 microg ml(-1) for hydrochlorothiazide. The intra- and interday R.S.D. values were <1.25% (n = 5), while the relative percentage error (Er) was <0.9% (n = 5). The detection limits attained according to IUPAC definition were 0.88 and 0.58 microg ml(-1) for benazepril hydrochloride and hydrochlorothiazide, respectively. The method was applied in the quality control of commercial tablets and content uniformity test and proved to be suitable for rapid and reliable quality control.     

Simultaneous determination of hydrochlorothiazide and amiloride hydrochloride by ratio spectra derivative spectrophotometry and high-performance liquid chromatography

Rapid, precise, accurate and specific ratio spectra derivative spectrophotometry and high-performance liquid chromatographic procedures were described for the simultaneous determination of hydrochlorothiazide and amiloride hydrochloride in combined pharmaceutical dosage forms. For the first method, ratio spectra derivative spectrophotometry, the signals were measured at 285.7 nm for hydrochlorothiazide and at 302.5 nm for amiloride hydrochloride in the mixture, in the first derivative of the ratio spectra. The second method is based on high-performance liquid chromatography (HPLC) on LiChrosorb RP-C18 column (5 microm, 20 cm x 4.6 mm) using 0.025 M orthophosphoric acid (adjusted to pH 3.0 with triethylamine (TEA)), acetonitrile (84:16 v/v) as a mobile phase at a flow rate of 1.2 ml/min(-1). Detection was carried out using a UV detector at 278.0 nm. Commercial sugar-coated and laboratory-prepared mixtures containing both drugs in different proportions were assayed using the developed methods.     

Simultaneous determination of moexipril hydrochloride and hydrochlorothiazide in tablets by derivative spectrophotometric and high-performance liquid chromatographic methods

Two new simple and selective assay methods have been presented for the binary mixtures of moexipril hydrochloride (MOEX) and hydrochlorothiazide (HCTZ) in pharmaceutical formulations. The first method depends on second-derivative ultraviolet spectrophotometry with zero-crossing measurements at 215 and 234 nm for MOEX and HCTZ, respectively. The assay was linear over the concentration ranges 1.0-11.0 microg ml(-1) for MOEX and 0.5-9.0 microg ml(-1) for HCTZ. The determination limits for MOEX and HCTZ were found to be 1.0 and 0.5 microg ml(-1), respectively; while the detection limits were 0.2 microg ml(-1) for MOEX and 0.1 microg ml(-1) for HCTZ. The second method was based on isocratic reversed-phase liquid chromatography by using a mobile phase acetonitrile-20 mM phosphate buffer (pH 4.0) (50:50, v/v). Lisinopril was used as an internal standard (IS) and the substances were detected at 212 nm. The linearity range for both drugs was 0.5-12.0 microg ml(-1). The determination and detection limits were found to be 0.100 and 0.010 microg ml(-1) for MOEX and 0.025 and 0.005 microg ml(-1) for HCTZ, respectively. The proposed methods were successfully applied to the determination of these drugs in synthetic mixtures and commercially available tablets with a high percentage recovery, good accuracy and precision.     

Simultaneous determination of valsartan and hydrochlorothiazide in tablets by first-derivative ultraviolet spectrophotometry and LC

First-derivative ultraviolet spectrophotometry and high-performance liquid chromatography (HPLC) were used to determine valsartan and hydrochlorothiazide simultaneously in combined pharmaceutical dosage forms. The derivative procedure was based on the linear relationship between the drug concentration and the first derivative amplitudes at 270.6 and 335 nm for valsartan and hydrochlorothiazide, respectively. The calibration graphs were linear in the range of 12.0–36.1 μg ml⁻¹ for valsartan and 4.0–12.1 μg ml⁻¹ for hydrochlorothiazide. Furthermore, a high- performance liquid chromatographic procedure with ultraviolet detection at 225 nm was developed for a comparison method. For the HPLC procedure, a reversed phase column with a mobile phase of 0.02 M phosphate buffer (pH 3.2)-acetonitrile (55: 45; v/v), was used to separate for valsartan and hydrochlorothiazide. The plot of peak area ratio of each drug to the internal standard versus the respective concentrations of valsartan and hydrochlorothiazide were found to be linear in the range of 0.06–1.8 and 0.07–0.5 μg ml⁻¹, respectively. The proposed methods were successfully applied to the determination of these drugs in laboratory-prepared mixtures and commercial tablets.     

Simultaneous determination of paracetamol and methocarbamol in tablets by ratio spectra derivative spectrophotometry and LC

The application of the ratio spectra derivative spectrophotometry and high-performance liquid chromatography (HPLC) to the simultaneous determination of paracetamol (PAR) and methocarbamol (MET) in combined pharmaceutical tablets is presented. The spectrophotometric procedure is based on the use of the first derivative of the ratio spectra obtained by dividing the absorbtion spectrum of the binary mixtures by a standard spectrum of one of the compounds. The first derivative amplitudes were measured at 243.0 and 230.3 nm for the assay of PAR and MET, respectively. Calibration graphs were established for 2-30 microg ml for PAR and 2-36 microg/ml for MET in binary mixture. The detection limits for PAR and MET were found 0.097 and 0.079 microg/ml, respectively; while the quantification limits were 0.573 microg/ml for PAR and 1.717 microg/ml for MET. For the HPLC procedure, a reversed-phase column with a mobile phase of methanol-water (60:40, v/v), was used to separate both compounds with a detection of 274.0 nm. Linearity was obtained in the concentration range of 2 300 and 1.5-375 microg/ml for PAR and MET, respectively. The detection and quantification limits were found to be 0.42 and 1.4 microg/ml for PAR and 0.36 and 1.2 microg/ml for MET, respectively. The relative standard deviations were found to be less than 0.52%, indicating reasonable repeatibility of both methods. The proposed methods were successfully applied to the determination of these drugs in commercial tablets.     

HPLC法同时检测氢氯噻嗪和盐酸可乐定

目的:采用高效液相色谱法同时测定氢氯噻嗪和盐酸可乐定。方法:phenomenex fusion-RP色谱柱(4.6mm×250mm,4μm);流动相:甲醇-水-磷酸(25:75:0.08);检测波长220nm;柱温25℃;流量1mL.min-1。氢氯噻嗪的检测灵敏度0.05AUFS,盐酸可乐定的检测灵敏度0.005AUFS。结果:氢氯噻嗪和盐酸可乐定的线性范围分别为20-400μg.mL-1(r=0.9999)和75~1500ng.mL-1(r=0.9999),平均回收率分别为99.3%和99.2%。结论:该法简便准确,可用于氢氯噻嗪和盐酸可乐定复方制剂含量的同时测定。     

荧光分光光度法测定盐酸环丙沙星片的含量

采用荧光分光光度法测定盐酸环丙沙星片的含量简便、快速、灵敏度高。线性范围为０．１～０．５μｇ／ｍｌ，平均回收率为１００．０４％，相对标准差为０．６０％。     

Simultaneous determination of imipramine and amitryptiline by derivative spectrophotometry

Three methods are proposed for the simultaneous determination of imipramine and amitryptiline by derivative spectrophotometry, one of them using both first- and second-derivative spectra, and the others using the first- and second-derivative spectra, respectively, obtained from a "diode array" spectrophotometer. The methods allow the determination of 0.62-10.14 micrograms ml-1 of imipramine, and 0.63-10.04 micrograms ml-1 of amitryptiline, and have been applied to their determination in blood serum.     

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.     

Spectrophotometric determination of benazepril hydrochloride and hydrochlorothiazide in binary mixture using second derivative, second derivative of the ratio spectra and chemometric methods

Different spectrophotometric methods are presented for the simultaneous determination of benazepril hydrochloride and hydrochlorothiazide in pharmaceutical tablets. The first method depends on second derivative (2D) ultraviolet spectrophotometry, with zero crossing and peak to base measurement. The second derivative amplitudes at 214.8 and 227.4 nm were selected for the assay of benazepril hydrochloride and hydrochlorothiazide, respectively. The second method depends on second derivative of the ratio spectra by measurement of the amplitudes at 241.2 and 273.2 nm for benazepril hydrochloride and hydrochlorothiazide, respectively. Chemometric methods, classical least squares and principal component regression, were applied to analyze the mixture. Both the chemometric methods were applied to the zero and first order spectra of the mixture. The proposed methods were successfully applied for the determination of the two drugs in laboratory prepared mixtures and in commercial tablets.     

一阶导数光谱法测定盐酸地尔硫(艹/卓)缓释片的含量

目的 :建立测定盐酸地尔硫艹卓 缓释片的含量测定方法。方法 :以乙醇为溶剂 ,以一阶导数光谱的谷 -零位值法测定盐酸地尔硫艹卓 的含量 ,测定波长λ谷 =2 50± 1nm。结果 :回收率 1 0 0 .0 1 % ,RSD 0 .3 8%～ 0 .4 7% ,线性范围2 .4～ 1 6.8μg/ml。 结论 :方法简便、快速、准确 ,适合于该制剂的含量测定。     

一阶导数光谱法测定盐酸地尔硫缓释片的含量

目的:建立测定盐酸地尔硫艹卓缓释片的含量测定方法。方法:以乙醇为溶剂,以一阶导数光谱的谷-零位值法测定盐酸地尔硫艹卓的含量,测定波长λ谷=2 50±1nm。结果:回收率100.01% ,RSD0.38%～0.47% ,线性范围2.4～16.8μg/ml。结论:方法简便、快速、准确,适合于该制剂的含量测定。     

一阶导数紫外光谱法测定盐酸芬氟拉明片的含量及含量均匀度

目的：建立一阶导数紫外光谱法测定盐酸芬氟拉明片的含量及含量均匀度,以增加质量控制方法。方法：用水作溶剂,在２８０与２２０ｎｍ波长范围内测定一阶导数光谱,以一阶导数光谱在２６５ｎｍ与２６９ｎｍ波长处峰－谷间的振幅Ｄ为定量依据,用对照品对照法计算含量及含量均匀度。结果：盐酸芬氟拉明浓度在０．０５～０．４ｍｇ／ｍｌ之间与－阶导数峰－谷间的振幅呈良好的线性关系,相关系数ｒ－０．９９９９,６次的平均加样回收     

HPLC法测定复方盐酸贝那普利片中盐酸贝那普利和苯磺酸氨氯地平的含量

目的建立复方盐酸贝那普利片中盐酸贝那普利和苯磺酸氨氯地平含量测定的HPLC法。方法采用Diamonsil C18柱(200 mm×4.6 mm,5μm);流动相为氯化钾溶液(1 000 mL中含90 mmoL氯化钾和10 mmoL盐酸,pH值2.06)-水-甲醇(体积比为17∶25∶58),每1 000 mL流动相中加入612 mg高氯酸钠;流速为1 mL.min-1;检测波长为240 nm;柱温为35℃;进样量为20μL。结果盐酸贝那普利与苯磺酸氨氯地平可达到较好分离,盐酸贝那普利的质量浓度在10.0～200.0mg.L-1内与峰面积呈良好的线性关系(r=0.999 8);苯磺酸氨氯地平(按氨氯地平计)质量浓度在5～100 mg.L-1内与峰面积呈良好的线性关系(r=0.999 8)。盐酸贝那普利与苯磺酸氨氯地平的平均回收率分别为99.9%(n=9)和100.4%(n=9)。结论 HPLC法适用于复方盐酸贝那普利片中盐酸贝那普利和苯磺酸氨氯地平的含量测定。     

UVA/UVB sunscreen determination by second-order derivative ultraviolet spectrophotometry.

UVA/UVB protective agents are important constituents in many cosmetics and sunscreen preparations. Analytical methodologies which enable the determination of combined substances with different spectrophotometric characteristics are therefore useful and cost-effective. To this end, the following substances in a sunscreen gel were analyzed: the UVB and UVA protective substances, 2-hydroxy-4-methoxy-benzophenone-5-sulphonic acid (BZP) and 2-phenylbenzymidazole-5-sulphonic acid (PBS), respectively, were evaluated by second-order derivative ultraviolet spectrophotometry in distinct solvents and wavelengths. The method used for determination of BZP in 95% ethanol was the zero-peak (ZP) at 356.0 nm. For PBS, the solvent used was 0.1 mol l-1 triethanolamine, and the methods were the ZP at 317.5 nm and the peak-peak (PP) at 317.5-323.0 nm. Statistical results for the methods showed linearity of 0.9999 and an average precision of 1.12% (ZP) for BZP, and 0.55% (ZP) and 0.63% (PP) for PBS. The average recovery for BZP and PBS were 97.28% (ZP), 103.13% (ZP) and 103.71% (PP), respectively.     

紫外分光光度法测定盐酸安妥沙星片中主药的含量

目的建立以紫外分光光度法测定盐酸安妥沙星片中主药含量的方法。方法以盐酸溶液为空白,在297 nm波长处照分光光度法测定盐酸安妥沙星的吸收度。结果安妥沙星检测浓度的线性范围为3.02～10.57 mg.L-1(r=0.999 7);平均回收率为99.93%,RSD=0.66%。结论该方法快捷、简便、灵敏度高,可用于该制剂的含量测定。     

一阶导数紫外分光光度法测定瑞巴派特片中瑞巴派特的含量

瑞巴派特是一种新型胃粘膜保护剂 ,具有预防溃疡发生和促进溃疡愈合的作用 ,可增加胃粘膜血流量、前列腺素 E2的合成和胃粘液分泌 ,并促进消化性溃疡的愈合及炎症的改善。新药暂行标准 [1 ] 采用以二甲基甲酰胺作溶剂的碱量法测定含量 ,文献报道主要有高效液相色谱法 [2 ] 。本文建立了以p H6 .8的磷酸盐缓冲液作溶剂的一阶导数紫外分光光度法测定瑞巴派特片含量的方法 ,可消除片剂中全辅料的干扰。结果表明 ,本法与碱量法测定结果一致。本法操作简便、省时 ,专属性强 ,结果满意。1　仪器与试药1.1　仪器　 U V- 2 5 6 FW型紫外可见分光…     

RP-HPLC法同时测定复方盐酸二甲双胍片中盐酸二甲双胍和格列美脲的含量

目的建立同时测定复方盐酸二甲双胍片中格列美脲和盐酸二甲双胍含量的方法。方法采用RP-HPLC法。色谱柱为Diamonsil C18柱(150 mm×4.6 mm,5μm),流动相为乙腈-20 mmol.L-1磷酸氢二钠溶液(含8 mmol.L-1十二烷基硫酸钠,磷酸调pH值7.5)(体积比为33∶67),流速为1 mL.min-1,检测波长为228 nm。结果格列美脲和盐酸二甲双胍的线性范围分别为0.1～0.6 mg.L-1(r=0.999 1,n=6)和25.0～150.0 mg.L-1(r=0.999 6,n=6);平均回收率分别为99.4%(RSD=1.0%,n=9)和99.8%(RSD=0.39%,n=9)。结论本方法简便、准确,可用于复方盐酸二甲双胍片的质量控制。