Quantitation of olanzapine in tablets by HPLC, CZE, derivative spectrometry and linear voltammetry

Four analytical methods have been developed for the quality control of pharmaceutical formulations containing the novel antipsychotic drug, olanzapine: high performance liquid chromatography (HPLC), capillary zone electrophoresis (CZE), derivative spectrometry and linear voltammetry. All methods require only a simple extraction procedure of olanzapine from the tablets before analysis. HPLC with ultraviolet detection at 260 nm is carried out with a C8 column and a mobile phase constituted of acetonitrile and aqueous tetramethylammonium perchlorate. CZE is performed in an uncoated capillary with phosphate buffer, pH 3.0, as the background electrolyte, with UV detection at 214 nm. Spectrophotometry uses the derivative of the spectrum at 298 nm. In linear voltammetric method (LSV) the current intensity of the oxidation wave at +495 mV is measured. All methods gave similar results in terms of precision and accuracy. For HPLC and CZE, repeatability and intermediate precision, expressed by the RSD was better than 1.8%. The accuracy, resulting from recovery experiments, was between 99.9 and 101.1%. Spectrometry and voltammetry gave slightly higher RSD values (up to 2.9%) and a larger variation of the accuracy (the recovery was between 97.8 and 102.6%). However, the requirements for quantitative analysis are fulfilled for all methods.     

Determination of citalopram in tablets by capillary zone electrophoresis and by direct and derivative UV-spectrophotometry

Three rapid, simple and accurate analytical methods for the determination of citalopram in tablets were developed. The capillary zone electrophoresis (CZE) method was carried out using fused silica capillary with 67 mM phosphate buffer pH 7.0 as the background electrolyte, 30 kV of separation voltage and UV detection at 239 nm. The direct spectrophotometric method was performed by measuring the absorbance at the wavelength of 239 nm and derivative spectrophotometric assay was carried out by measuring the value of the second derivative of the spectrum at 210 nm. The linearity range for CZE method was 5-50 microg/mL and for both spectrophotometric methods was 2-12 microg/mL. The recovery in CZE was between 98.6 and 102.4%, in the direct spectrophotometry between 95.0 and 98.0% and in derivative spectrophotometry between 97.6 and 103.3%. The RSD values were between 1.36 and 2.30%, 1.80 and 2.70%, 1.52 and 2.68%, respectively.     

Comparison of capillary zone electrophoresis and high performance liquid chromatography methods for quantitative determination of ketoconazole in drug formulations

A capillary zone electrophoresis (CZE) and a high-performance liquid chromatography (HPLC) method have been developed for identification and determination of ketoconazole, an imidazole antifungal, in pharmaceutical preparations. The suitabilities of both methods for quantitative determination of ketoconazole were approved through validation specification such as linearity, precision, accuracy, limit of detection and quantification. The proposed methods were used for determination of ketoconazole in commercial pharmaceutical dosage forms (tablets and creams). Under described conditions, CZE method is more selective, while the HPLC method is more sensitive. Both methods are rapid (tR(CZE)=5.14 min and tR(HPLC)=2.66 min), which is important for routine application. However, the HPLC method provides a repeatability of the quantitative analysis of ketoconazole in drug formulations below 1.5% relative standard deviation (R.S.D), while the repeatability of the CZE method is in the order of 2-3% R.S.D.     

Method development and validation for the simultaneous determination of cetirizine dihydrochloride, paracetamol, and phenylpropanolamine hydrochloride in tablets by capillary zone electrophoresis

A simple, selective, and cost effective capillary zone electrophoresis (CZE) method has been developed for the simultaneous separation and determination of cetirizine dihydrochloride (CTZ), paracetamol (PARA), and phenylpropanolamine hydrochloride (PPA) in tablets. A 10 mM sodium tetraborate background electrolyte (BGE) solution (pH 9.0) was found to be suitable for separation of all the analytes. An uncoated fused-silica capillary of a total length of 76 cm (effective length 64.5 cm) was used for separation. All the analytes were completely separated within 10 min at the applied voltage of 20 kV (current produced approximately 21 microA), and detection was performed at 195 nm with an UV detector. Ibuprofen was used as internal standard (I.S.) for the quantification of the drugs. Validation of the method was performed in terms of linearity, accuracy, precision, limit of detection (LOD), and quantification (LOQ). The linearity of the calibration curves for CTZ, PARA, and PPA (tested range) were 2-50 microg ml(-1) (r(2)=0.9982), 10-1000 microg ml(-1) (r(2)=0.9978), and 10-100 microg ml(-1) (r(2)=0.9986), respectively. The proposed method has been applied for the determination of active ingredients in tablets, and the recovery was found to be > or =98.60% with the relative standard deviation (R.S.D.) < or =1.56%. The LOQ of the CTZ, PARA, and PPA was found to be 2.0, 2.0, and 4.0 microg ml(-1), respectively. There were no interfering peaks due to the excipients present in the pharmaceutical tablets. Thus, the proposed method is simple and suitable for the simultaneous analysis of active ingredients in tablet dosage forms.     

Determination of cisapride in pharmaceutical preparations using derivative spectrophotometry

Derivative spectrophotometric and high performance liquid chromatographic methods (HPLC) were described for the determination of cisapride in pharmaceutical preparations. Spectrophotometrically, cisapride was determined by measuring the 1D-values at 264, 300 nm and 2D-values at 276, 290 and 276-290 nm. Beer's Law was obeyed in the range 2-12 microg ml(-1). The HPLC method depends upon using micropack-Si-10 column at ambient temperature with a mobile phase consisting of methanol-concentrated ammonia (99.25:0.75) at a flow rate of 1 ml min(-1). Quantitation was achieved by UV detection at 272 nm using quinine as internal standard. Calibration curve was linear over the concentration range 2-10 microg ml(-1). Both derivative spectrophotometry and HPLC methods showed good linearity, precision and reproducibility. No interference was found from tablet or suspension matrices at the selected derivative wavelengths and chromatographic conditions. The proposed methods were successfully applied to the assay of commercial tablets and suspension. The procedures were rapid, simple and suitable for quality control applications.     

Determination of mirtazapine in tablets by UV spectrophotometric and derivative spectrophotometric methods

Mirtazapine, 1, 2, 3, 4, 10, 14b-hexahydro-2-methyl-pyrazino [2, 1-a] pyrido [2, 3-c] [G.L. Stimmel, J.A. Dopheide and S.M. Stahl, Pharmacotheraphy 17(1) (1997) 10] benzazepine, is a new and well tolerated antidepressant. It blocks pre-synaptic alpha2-adrenergic receptors and postsynaptic serotonin type 2 and type 3 receptors. The drug is rapid and completely absorbed after oral administration. Mirtazapine was analyzed by HPLC and gas chromatography with nitrogen-sensitive detection. In this study, mirtazapine was analyzed by using UV spectrophotometry, first and second order derivative spectrophotometry. The type of solvent, the degree of derivation, range of wavelength and n value were chosen in order to optimize the conditions. The concentration of mirtazapine in its methanolic solutions were determined between the wavelength range of 225-360 nm in the linearity range of 1-100, 2-100 and 1-120 microg ml(-1) by using the values obtained from UV. first-order derivative (n = 5, delta lambda = 17.5 nm) and second-order derivative (n = 9, delta lambda = 31.5 nm) spectrum of the substance, respectively. The developed UV Spectrophotometric, first-order and second-order derivative spectrophotometric methods were applied to a pharmaceutical preparation as tablet form. Developed UV and derivative UV spectrophotometric method in this study are accurate, sensitive, precise, reproducible and can be directly and easily applied to the pharmaceutical preparations.     

Quality control of commercial tablets containing the novel antipsychotic quetiapine

Quetiapine (bis [2-(2-[4-(dibenzo[b,f][1,4]thiazepin-11-yl]ethoxy)ethanol]fumarate) is the most recent agent introduced on the drug market for the treatment of psychotic disorders. Two different analytical methods for the quality control of quetiapine in commercial formulations have been developed and compared: a spectrophotometric method and a capillary zone electrophoretic (CZE) method. The spectrophotometric assay was carried out measuring the absorbance at a wavelength of 246 nm. The CZE method used an uncoated fused-silica capillary and a pH 2.5, 50 mM phosphate buffer as the background electrolyte. The detection wavelength was 205 nm, the separation voltage was 15 kV, and a complete electrophoretic run lasts less than 2.5 min. Extraction of quetiapine from the commercial tablets consisted of a simple one-step treatment with a pH 2.5, 50 mM phosphate buffer. Linearity was observed in the 5-25 microg ml(-1) concentration range of quetiapine for the spectrophotometric method, and in the 5-50 microg ml(-1) concentration range for the electrophoretic method. Both methods gave satisfactory results in terms of repeatability and intermediate precision (RSD<1.9%). Also accuracy values were very good for both methods, the recovery being between 98.2 and 100.5%.     

RP-HPLC法测定罗红霉素片中罗红霉素的含量

目的建立罗红霉素片含量测定的高效液相色谱法,并与微生物检定法、紫外分光光度法的测定结果进行比较。方法采用Agilent-C18色谱柱（4.6 mm×250 mm,5μm）;0.067 mol·L^-1磷酸二氢铵（三乙胺调节pH6.5）-乙腈（3∶2）,加入1%的三乙胺,用磷酸调节pH7.2为流动相;流速1.0 ml·min^-1;检测波长211 nm;柱温30℃。结果罗红霉素在2.14～42.80 mg·L^-1的浓度范围内有良好的线性关系（r=0.999 9）,平均回收率为97.8%,RSD为0.78%（n=5）。结论三种含量测定方法的结果相近,均可用于罗红霉素片的含量测定。     

Comparison of HPLC, UV spectrophotometry and potentiometric titration methods for the determination of lumefantrine in pharmaceutical products

This paper describes the development and evaluation of a HPLC, UV spectrophotometry and potentiometric titration methods to quantify lumefantrine in raw materials and tablets. HPLC analyses were carried out using a Symmetry C(18) column and a mobile phase composed of methanol and 0.05% trifluoroacetic acid (80:20), with a flow rate of 1.0ml/min and UV detection at 335nm. For the spectrophotometric analyses, methanol was used as solvent and the wavelength of 335nm was selected for the detection. Non-aqueous titration of lumefantrine was carried out using perchloric acid as titrant and glacial acetic acid/acetic anhydride as solvent. The end point was potentiometrically determined. The three evaluated methods showed to be adequate to quantify lumefantrine in raw materials, while HPLC and UV methods presented the most reliable results for the analyses of tablets.     

RP-HPLC and UV Spectrophotometric Methods for Estimation of Pirfenidone in Pharmaceutical Formulations

High-performance liquid chromatographic and UV spectrophotometric methods were developed and validated for the quantitative determination of pirfenidone, a novel antifibrotic agent used in idiopathic pulmonary fibrosis. Chromatography was carried out by isocratic technique on a reversed-phase C₁₈ Zorbax Eclipse plus column with mobile phase consisting of acetonitrile:water (35:65 %v/v) at flow rate of 0.7 ml/min. The UV spectrophotometric determinations were performed at 317 nm using methanol as a solvent. The proposed methods were validated according to International Conference on Harmonization ICH Q2 (R1) guidelines. The linearity range for pirfenidone was 0.2-5.0 and 3-25 μg/ml for HPLC and UV method, respectively. Both the methods were accurate and precise with recoveries in the range of 98 and 102 % and relative standard deviation <2 %. The developed methods were successfully applied for determination of pirfenidone in tablets.     

Fast and single solid phase fluorescence spectroscopic batch procedure for (acetyl) salicylic acid determination in drug formulations

A solid phase fluorescence spectroscopic batch procedure for (acetyl) salicylic acid in drug formulations have been developed. The procedure is based on the sorption of salicylic acid (SA) on Sephadex DEAE A-25 anion exchanger gel (100 mg) by equilibration from an aqueous solution (10 or 25 ml) for 5 min; the equilibrated gel is transferred into an 1 mm quartz cell and the native fluorescence of SA sorbed on it is directly measured (lambda(ex)=297 nm; lambda(em)=405 nm). Good linearity was found in the 10-200 and 5-100 microg l(-1) ranges (for 10 and 25 ml sample volume, respectively) with R.S.D. (%) of 2.8 and 1.1. The procedure was successfully applied to the determination of acetyl salicylic acid (ASA) in drug formulations after alkaline hydrolysis to yield SA.     

A Stability-indicating High Performance Liquid Chromatographic Assay for the Simultaneous Determination of Atenolol and Lercanidipine Hydrochloride in Tablets

A simple, rapid, precise and accurate isocratic reversed phase stability indicating HPLC method was developed and validated for the simultaneous determination of atenolol and lercanidipine hydrochloride in commercial tablets. The chromatographic separation was achieved on phenomenex Gemini C18 (250×4.6 mm, 5 μm) column using a mobile phase consisting of acetonitrile and buffer (20 mM potassium dihydrogen phosphate pH 3.5) in the ratio of (55:45, v/v) at a flow rate of 1.0 ml/min and UV detection at 235 nm. The linearity of the proposed method was investigated in the range of 40-160 μg/ml (r(2)=0.9995) for atenolol and 8-32 μg/ml (r(2)=0.9993) for lercanidipine. Degradation products produced as a result of stress studies did not interfere with the detection of atenolol and lercanidipine and the assay can thus be considered stability-indicating.     

高效液相色谱法测定妇科止带片中盐酸小檗碱的含量

目的 :建立以高效液相色谱法测定妇科止带片中盐酸小檗碱含量的方法。方法 :色谱柱为十八烷基键合硅胶柱 ,流动相为0 05mol/L磷酸二氢钠溶液 -乙腈 (75∶25) ,检测波长为270nm ,流速为1 0ml/min ,柱温为室温。结果 :盐酸小檗碱在48 8～341 6μg/ml检测浓度范围内线性关系良好 (r=0 9990 ,n=7) ,平均回收率为98 8 % (RSD=0 72 % )。结论 :本法操作简便、灵敏度高、重现性好     

Application of first-derivative UV-spectrophotometry, TLC-densitometry and liquid chromatography for the simultaneous determination of mebeverine hydrochloride and sulpiride

Three methods are described for the simultaneous determination of mebeverine hydrochloride (MB) and sulpiride (SU) in combined pharmaceutical tablets. The first method depends on first-derivative ultraviolet spectrophotometry, with zero-crossing measurement method. The first derivative amplitudes at 214.2 and 221.6 nm were selected for the assay of MB and SU, respectively. Calibration graphs follow Beer's law in the range of 10-30 and 2-8 microg/ml(-1), and the linearity was satisfactory (r = 0.9999), for MB and SU, respectively. The second method was based on the application of the thin layer chromatographic separation of both drugs followed by the densitometric measurements of their spot areas. After separation on silica gel GF254 plates, using ethanol: diethyl ether: triethylamine (70:30:1 v/v) as the mobile phase, the chromatographic zones corresponding to the spots of MB and SU were scanned at 262 and 240 nm, respectively. The calibration function was established in the ranges of 4-12 microg for MB and 2-8 microg for SU. The third method was an internal standard procedure based on high performance liquid chromatographic separation of the two drugs on a reversed-phase, Bondapak CN column. The detection was done at 243 nm using buclizine hydrochloride as internal standard. All chromatographic methods showed good linearity, precision and reproducibility. No spectral or chromatographic interference from the tablet excipients were found. The proposed methods were successfully applied to the assay of commercial tablets and content uniformity test. The procedures were rapid, simple and suitable for quality control application.     

Comparison of spectrophotometric and an LC method for the determination perindopril and indapamide in pharmaceutical formulations.

A new sensitive, simple, rapid and precise reversed-phase high performance liquid chromatographic (HPLC) and two spectrophotometric methods have been developed for resolving binary mixture of perindopril and indapamide in the pharmaceutical dosage forms. The first method is based on HPLC on a reversed-phase column using a mobile phase of phosphate buffer pH 2.4 and acetonitrile (7:3 v/v) was used. Linearity range for perindopril and indapamide was 5.0-70.0 and 8.0-35.0 microg ml(-1). In the second method, the first derivative spectrophotometry with a zero-crossing technique of measurement is used for the simultaneous quantitative determination of perindopril and indapamide in binary mixtures without previous separation step. Linear calibration graphs of first derivative values at 225.7 and 255.4 nm for perindopril and indapamide, respectively. The third method is based on ratio derivative spectrophotometry, the amplitudes in the first derivative of the ratio spectra at 226.5 and at 255.3 nm were selected to determine perindopril and indapamide in the binary mixture. All the proposed methods showed good linearity, precision and reproducibility. The proposed methods were successfully applied to the pharmaceutical dosage forms containing the above-mentioned drug combination without any interference by the excipients.     

差示分光光度法测定安乃近片的含量

目的:建立测定安乃近片含量的新方法。方法:采用差示分光光度法。以0.1mol.L-1盐酸溶液为介质制备参比液,以0.1mol.L-1氢氧化钠溶液为介质制备样品液,通过在波长283nm处,测定2种溶液的差示吸收值直接测定安乃近的含量,并将结果与其他方法(紫外分光光度法、高效液相色谱法和碘量法)比较。结果:安乃近检测浓度线性范围为10.35～51.75μg.L-(1r=0.9998),平均回收率为99.94%,RSD=0.27%(n=5);4种方法含量测定结果基本一致。结论:建立的新方法测定结果准确,方法简便、专属性强,可用于该制剂的含量测定。     

Spectrophotometric and fluorimetric determination of aztreonam in bulk and dosage forms

Spectrophotometric and fluorimetric determination of aztreonam were achieved through its reaction with cerium (IV) in acidic medium. The spectrophotometric method involves the quantitation of the amount of ceric equivalent to aztreonam by measuring the absorbance at 317 nm and the corresponding first-derivative value at 284 nm for the blank solution against the reaction solution. Beer's law is obeyed over the concentration ranges of 1.5-4 and 1-4 microg ml(-1), respectively. Meanwhile, in the fluorimetric method, higher sensitivity was achieved by measuring the fluorescence intensity of the formed cerium (III) at lambda(em)=357 nm (lambda(ex)=257 nm) within a concentration range 150-350 ng ml(-1). Study of the reaction conditions and reaction stoichiometry were presented. Interference from L-arginine, which is frequently co-formulated with aztreonam, was tested. The proposed procedures were applied successfully to the determination of aztreonam in pure form and in presence of arginine both in laboratory mixtures and commercial vials. The proposed methods are sensitive, accurate and precise as compared with the official USP 24 HPLC method.     

Colorimetric and fluorimetric methods for determination of panthenol in cosmetic and pharmaceutical formulation

Two methods are suggested for determination of panthenol. The first is colorimetric method where panthenol is subjected to alkaline hydrolysis; the resulting beta-alanol is allowed to react with vanillin (Duquenois reagent) in presence of McIlvain buffer pH 7.5. The color developed is measured at 406 nm. The linearity range was found to be 50-500 microg/ml while the lower limit of detection was about 10 microg/ml. The second is a sensitive and reliable modified fluorimetric method is also suggested, whereas panthenol, after alkaline hydrolysis is treated with ninhydrin. The fluorescent product was found to have excitation lambda(max) at 385 nm and emission lambda(max) at 465 nm. The method showed high sensitivity with linearity range from 0.01 to 3 microg/ml. The lower limit of detection (LOQ) reached 0.005 microg/ml. Validation of both methods was carried out and the two methods were applied for determination of panthenol in some cosmetic and pharmaceutical formulations.     

琥珀酸亚铁片3种含量测定方法的比较

目的:建立测定琥珀酸亚铁片含量的分光光度法和高效液相色谱(HPLC)法,并与现行标准方法硫酸铈法的测定结果进行比较。方法:分光光度法利用Fe2+与邻二氮菲在适宜条件下生成有色配合物,在510nm波长处测定吸光度;HPLC法条件为色谱柱为C18、流动相为0.05mol·L-1KH2PO(4pH=2.5),检测波长为215nm,以外标法定量。结果:分光光度法及HPLC法中Fe2+检测浓度线性范围分别为0.04244～2.546mg·L-1、0.25～32.2mmol·L-(1r=0.9998、0.9990),方法平均回收率分别为99.5%、99.8%,日内及日间RSD分别小于1.9%、2.1%;硫酸铈法、分光光度法和HPLC法测定样品的含量结果平均值分别为36.28%、36.73%、29.13%。结论:分光光度法与硫酸铈法测定琥珀酸亚铁片中总的亚铁的含量结果无显著性差异,均可用于该制剂的质量控制,而HPLC法可用于该片剂中有效成分琥珀酸亚铁的含量测定。     

HPLC assay of acetylsalicylic acid,paracetamol, caffeine and phenobarbital in tablets

This paper present a HPLC method for simultaneous determination of acetylsalicylic acid, paracetamol, caffeine and phenobarbital in tablets, using chromatographic system consisting a Bio Rad 18 01 solvent pump, Rheodine 71 25 injector and Bio Rad 18 01 UV-Vis Detector. Separation was achieved using Bio SiL HL C18, 5 microm, 250 x 4.6 mm column. Mixture of acetonitrile-water (25:75 v/v) adjusted to pH 2.5 with phosphoric acid was used as a mobile phase at a flow rate of 2.0 ml min(-1). UV detection was at 207 nm range 0.01 AUFS. Under the same conditions it was possible to determine the level of salicylic acid. The chromatographic parameters such as retention times, capacity factor, peak asymmetry, selectivity factor and resolution factor was determined. The validation parameters: linearity (r > 0.998), intra-day precision (RSD: 0.36-1.89%) and inter-day precision (RSD: 0.58-2.18%), sensitivity (LOD: 9 x 10(-5)-1.7 x 10(-4) mg ml(-1) and LOQ: 2.5 x 10(-4)-5.6 x 10(-4) mg ml(-1)), accuracy (recoveries: 98.35-99.14%) and reproducibility (recovery values: 98.74-102.08% for acetylsalicylic acid, 99.93-102.11% for paracetamol, 98.25-102.12% for caffeine and 98.15-102.3% for phenobarbital) (RSD: 1.21-1.85%) were found to be satisfactory. The proposed HPLC method has been applied for the determination of acetylsalicylic acid, paracetamol, caffeine and phenobarbital in Malophenum tablets. The obtained RSD values were within 0.99-1.21%. The developed method is rapid and sensitive and therefore suitable for routine control of these drugs in dosage form.