http://www.hindawi.com The latest articles from Hindawi Publishing Corporation © 2013 , Hindawi Publishing Corporation . All rights reserved. Sun, 19 May 2013 15:37:37 +0000 http://www.hindawi.com/journals/cri/2013/464796/ A simple, precise, accurate, and reliable HPTLC method has been developed and validated for the analysis of EPE-Eperisone hydrochloride and PCM-Paracetamol in their combined dosage form. Identification and analysis were performed on 100 mm × 100 mm layer thickness 0.2 mm, precoated silica gel G60-F254 aluminum sheet, prewashed with methanol, and dried in an oven at 50°C for 5 min. Toluene : methanol : ethyl acetate : glacial acetic acid (4 : 3.5 : 2.5 : 0.05) (v/v/v/v) was used as mobile phase. Calibration plots were established showing the dependence of response (peak area) on the amount chromatographed. The validated calibration ranges were 200–700 ng/spot and 1300–4550 ng/spot for EPE and PCM with correlation coefficient (R2) 0.994 and 0.996, respectively. Average % recovery was between 98.61–100.94% and 99.18–100.57% for EPE and PCM, respectively. The spots were scanned at 248 nm in a reflectance mode. The proposed method was validated as per ICH guidelines and successfully applied to the estimation of EPE and PCM in their combined tablet dosage form. Nirav Uchadadiya, Falgun Mehta, and Pinak Sanchaniya Copyright © 2013 Nirav Uchadadiya et al. All rights reserved. Wed, 15 May 2013 09:16:32 +0000 http://www.hindawi.com/journals/cri/2013/834173/ Chemical and physical degradation of drugs may result in altered therapeutic efficacy and even toxic effects. Therefore, the aim of this work was to study the stability of darunavir and to develop and validate a liquid chromatography (LC) method to determine darunavir in raw material and tablets in the presence of degradation products. The novel method showed to be linear from 6.0 to 21.0 μg/mL, with high precision (CV < 2%) and accuracy (recuperation of 99.64%). It is simple and reliable, free of placebo interferences. The robustness of the method was evaluated by a factorial design using seven different parameters. Forced degradation study was done under alkaline, acidic, and oxidative stress at ambient temperature and by heating. The LC method was able to quantify and separate darunavir and its degradation products. Darunavir showed to be unstable under alkaline, acid, and oxidative conditions. The novelty of this study is understanding the factors that affect darunavir ethanolate stability in tablets, which is the first step to unravel the path to know the degradation products. The novel stability-indicating method can be used to monitor the drug and the main degradation products in low concentrations in which there is linearity. Josilene Chaves Ruela Corrêa, Cristina Helena dos Reis Serra, and Hérida Regina Nunes Salgado Copyright © 2013 Josilene Chaves Ruela Corrêa et al. All rights reserved. Tue, 07 May 2013 11:33:50 +0000 http://www.hindawi.com/journals/cri/2013/747060/ A simple, specific, accurate, precise stability indicating reversed-phase high-performance liquid chromatographic (RP-HPLC) method was developed and validated for the simultaneous determination of pyridoxine hydrochloride (PYH) and meclizine hydrochloride (MEH). An isocratic separation of PYH and MEH were achieved on C 18, 250 × 4.6 mm ID, 5 μm particle size columns at column oven temperature 37°C with a flow rate of 0.5 mL min−1 and using a diode array detector to monitor the detection at 254 nm. The mobile phase consisted of buffer : acetonitrile : trifluoroacetic acid at a ratio of 30 : 70 : 0.1 (v/v). The retention times of PYH and MEH was found to be 5.25 and 10.14 min, respectively. Suitability, specificity, linearity, accuracy, precision, stability, and sensitivity of this method for the quantitative determination of the drugs were proved by validation in accordance with the requirements laid down by International Conference on Harmonization (ICH) Q2 (R1) guidelines. The proposed method is reliable and robust and can be used as quality control tool for the estimation of these drugs in combined pharmaceutical solid dosage forms. Md. Saddam Nawaz Copyright © 2013 Md. Saddam Nawaz. All rights reserved. Thu, 18 Apr 2013 08:30:45 +0000 http://www.hindawi.com/journals/cri/2013/676501/ Chromatographic and spectrophotometric methods were developed according to Quality by Design (QbD) approach as per ICH Q8(R2) guidelines for estimation of propafenone hydrochloride in tablet dosage form. QbD approach was carried out by varying various parameters and these variable parameters were designed into Ishikawa diagram. The critical parameters were determined by using principal component analysis as well as by observation. Estimated critical parameters in HPTLC method include solvent methanol, mode of detection absorbance, precoated aluminium backed TLC plate (10 cm 10 cm), wavelength: 250 nm, saturation time: 20 min, band length: 8 mm, solvent front: 70 mm, volume of mobile phase: 5 mL, type of chamber: 10 cm 10 cm, scanning time: 10 min, and mobile phase methanol : ethyl acetate : triethylamine (1.5 : 3.5 : 0.4 v/v/v). Estimated critical parameters in zero order spectrophotometric method were solvent methanol, sample preparation tablet, wavelength: 247.4 nm, slit width: 1.0, scan speed medium, and sampling interval: 0.2, and for first order derivative spectrophotometric method it was scaling factor: 5 and delta lambda 4. The above methods were validated according to ICH Q2(R1) guidelines. Proposed methods can be used for routine analysis of propafenone hydrochloride in tablet dosage form as they were found to be robust and specific. Monika L. Jadhav and Santosh R. Tambe Copyright © 2013 Monika L. Jadhav and Santosh R. Tambe. All rights reserved. Tue, 09 Apr 2013 13:22:29 +0000 http://www.hindawi.com/journals/cri/2013/963595/ A sensitive, precise, specific, linear, and stability-indicating gradient HPLC method was developed for the estimation of doripenem in active pharmaceutical ingredient (API) and in injectable preparations. Chromatographic separation was achieved on C18 stationary phase with a mobile phase gradient consisting of acetonitrile, methanol, and pH 5.2 phosphate buffer. The mobile phase flow rate was 0.8 mL/min, and the eluted compounds were monitored at 210 nm. The method is linear over the range of 0.335 to 76.129 µg/mL. The correlation coefficient was found to be 0.999. The numbers of theoretical plates and tailing factor for doripenem were 53021 and 0.9, respectively. Doripenem was subjected to the International Conference on Harmonization (ICH) prescribed hydrolytic (acid, base, and neutral), oxidative, photolytic, and thermal stress conditions. Among all the above-mentioned conditions, the drug was found to be stable under photolytic degradation. Peak homogeneity data for doripenem in the chromatograms from the stressed samples obtained by use of the photodiode array detector demonstrated the specificity of the method for analysis of doripenem in presence of the degradation products. The performance of the method was validated according to the present ICH guidelines for specificity, limit of detection, limit of quantification, linearity, accuracy, precision, and robustness. Singaram Kathirvel and Garikapati Devalarao Copyright © 2013 Singaram Kathirvel and Garikapati Devalarao. All rights reserved. Sun, 31 Mar 2013 08:12:17 +0000 http://www.hindawi.com/journals/cri/2013/404727/ The present paper describes the development of quick stability indicating RP-HPLC method for the simultaneous estimation of codeine phosphate and chlorpheniramine maleate in the presence of its degradation products, generated from forced degradation studies. The developed method separates codeine phosphate and chlorpheniramine maleate in impurities/degradation products. Codeine phosphate and chlorpheniramine maleate and their combination drug product were exposed to acid, base, oxidation, dry heat, and photolytic stress conditions, and the stressed samples were analysed by proposed method. The proposed HPLC method utilizes the Shimadzu HPLC system on a Phenomenex C18 column (, 5 μ) using a mixture of 1% o-phosphoric acid in water : acetonitrile : methanol (78 : 10 : 12) mobile phase with pH adjusted to 3.0 in an isocratic elution mode at a flow rate of 1 mL/min, at 23°C with a load of 20 μL. The detection was carried out at 254 nm. The retention time of codeine phosphate and chlorpheniramine maleate was found to be around 3.47 min and 9.45 min, respectively. The method has been validated with respect to linearity, robustness, precision, accuracy, limit of detection (LOD), and limit of quantification (LOQ). The developed validated stability indicating HPLC method was found to be simple, accurate, and reproducible for the determination of instability of these drugs in bulk and commercial products. Ramakrishna Kommana and Praveen Basappa Copyright © 2013 Ramakrishna Kommana and Praveen Basappa. All rights reserved. Thu, 14 Feb 2013 10:43:10 +0000 http://www.hindawi.com/journals/cri/2013/310269/ Simple, rapid, sensitive, precise, and accurate methods for detection and separation of seven diketopiperazines (DKPs), cyclo(Gly-Gly), cyclo(DL-Ala-DL-Ala), cyclo(L-Asp-L-Phe), cyclo(L-Asp-L-Asp), cyclo(Gly-L-Phe), cyclo(L-Pro-L-Tyr), and cyclo(L-Arg-L-Arg), from their corresponding linear dipeptides and related amino acids L-Phe and L-Tyr by reversed-phase high-performance liquid chromatography (RP-HPLC) were established. Moreover, for the racemic DKP cyclo(DL-Ala-DL-Ala) and dipeptide DL-Ala-DL-Ala, separation of the diastereomers was achieved. All methods can be performed within 15 min. For all DKPs, dipeptides, and amino acids, linear ranges with correlation coefficients greater than 0.998 were determined. Lowest limits of detection were found to be between 0.05 and 10 nmol per 10 μL injection, depending on the substance. For all tested substances intrarun and interrun precision ranged from 0.5 to 4.7% and 0.7 to 9.9% relative standard deviation, and accuracy was between −4.2 and 8.1% relative error. Short-term and freeze-thaw stabilities were 93% or greater for all substances. Recovery rate after heat treatment was determined to be at least 97%. These methods will be useful for quantitative determination of DKPs and their potential biodegradation products: dipeptides and amino acids Mareike Perzborn, Christoph Syldatk, and Jens Rudat Copyright © 2013 Mareike Perzborn et al. All rights reserved. Mon, 17 Dec 2012 14:59:12 +0000 http://www.hindawi.com/journals/cri/2012/748989/ The combination of liquid chromatography (LC) with mass spectrometry (MS) in the environmental field has appeared as a valuable tool for the determination of micropollutants. Several groups of compounds have been considered as particularly relevant (e.g., pharmaceuticals, hormones and other endocrine-disrupting, personal care products and their metabolites, flame retardants, surfactants, and plasticizers, among others) since the same ones are continuously being released in the environment mainly as a result of the manufacturing processes, the disposal of unused or expired products, and the excreta. Because these micropollutants are not completely removed in the environment, very specific and sensitive analytical procedures are needed for their identification and quantification. High performance liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS) (or LC-MS2) and especially time-of-flight mass spectrometry (TOF/MS), has allowed that many environmental contaminants that are highly polar or nonvolatile or have a high molecular weight to be analyzed or identified. In this work we present an overview focused on the developments of liquid chromatography mass spectrometry applied to the analysis of the main classes of micropollutants in aqueous and solid environmental samples. Various aspects of methodologies based on these techniques, including sample preparation (extraction/preconcentration) and matrix effects, are discussed. Zoraida Sosa-Ferrera, Cristina Mahugo-Santana, and José Juan Santana-Rodríguez Copyright © 2012 Zoraida Sosa-Ferrera et al. All rights reserved. Sun, 04 Nov 2012 15:35:12 +0000 http://www.hindawi.com/journals/cri/2012/948129/ Bengi Uslu, Henk Lingeman, Sibel A. Ozkan, Meehir Palit, and Burcu Dogan-Topal Copyright © 2012 Bengi Uslu et al. All rights reserved. Thu, 27 Sep 2012 19:11:43 +0000 http://www.hindawi.com/journals/cri/2012/135854/ Ion suppression in analysis of tetracyclines in feed was studied. The conventional analysis consists of a liquid extraction followed by a clean-up step using solid phase extraction (SPE) technique and analysis of the tetracyclines by liquid chromatography and mass spectrometric detection. Various strategies for extraction and cleanup were tested in the present work, and the effectiveness to decrease the ion suppression on the MS/MS signals was evaluated. Four sample treatment methods were tested with five different feed samples. Extraction solvents tested were McIlvaine buffer and a mixture of McIlvaine buffer dichloromethane (3 : 1). SPE cartridges for cleanup were Oasis HLB, Oasis MCX, and Oasis MAX. The effectiveness of the methods was evaluated in terms of decreasing the ion suppression effect but also of decreasing the variability of ion suppression between samples. The method that provided the most satisfactory results involved a clean-up step based on SPE using mixed-mode cation exchange cartridges (Oasis MCX). Joaquim Chico, Frederique van Holthoon, and Tina Zuidema Copyright © 2012 Joaquim Chico et al. All rights reserved. Sun, 09 Sep 2012 16:03:35 +0000 http://www.hindawi.com/journals/cri/2012/713273/ Micellar liquid chromatography (MLC) with the use of high performance liquid chromatography (HPLC) was used to determine some physicochemical parameters of six biogenic amines: adrenaline, dopamine, octopamine, histamine, 2-phenylethylamine, and tyramine. In this paper, an influence of surfactant’s concentration and pH of the micellar mobile phase on the retention of the tested substances was examined. To determine the influence of surfactant’s concentration on the retention of the tested amines, buffered solutions (at pH 7.4) of ionic surfactant—sodium dodecyl sulfate SDS (at different concentrations) with acetonitrile as an organic modifier (0.8/0.2 v/v) were used as the micellar mobile phases. To determine the influence of pH of the micellar mobile phase on the retention, mobile phases contained buffered solutions (at different pH values) of sodium dodecyl sulfate SDS (at 0.1 M) with acetonitrile (0.8/0.2 v/v). The inverse of value of retention factor (1/𝑘) versus concentration of micelles (𝐶𝑀) relationships were examined. Other physicochemical parameters of solutes such as an association constant analyte—micelle (𝐾ma)—and partition coefficient of analyte between stationary phase and water (hydrophobicity descriptor) (𝑃swΦ) were determined by the use of Foley’s equation. Irena Malinowska and Katarzyna E. Stępnik Copyright © 2012 Irena Malinowska and Katarzyna E. Stępnik. All rights reserved. Wed, 29 Aug 2012 16:09:32 +0000 http://www.hindawi.com/journals/cri/2012/801720/ A novel, simple, sensitive, stability indicating HPLC method was developed and validated for quantification of impurities (process related and degradants) and assay determination of bortezomib. Stability indicating power of the method was established by forced degradation experiments and mass balance study. The chromatographic separation was achieved with Waters SymmetryShield RP18 column using gradient elution using the mobile phase-A consists of a mixture of water-acetonitrile-formic acid (715 : 285 : 1, v/v/v) and the mobile phase-B consists a mixture of methanol-water-formic acid (800 : 200 : 1, v/v/v), respectively. The developed method is validated for parameters like precision, accuracy, linearity, LOD, LOQ, and ruggedness. Central composite experimental design (CCD) was applied to check the robustness of the method. The stability tests were also performed on drug substances as per ICH norms. Kasa Srinivasulu, Mopidevi Narasimha Naidu, Kadaboina Rajasekhar, Murki Veerender, and Mulukutla Venkata Suryanarayana Copyright © 2012 Kasa Srinivasulu et al. All rights reserved. Wed, 13 Jun 2012 10:06:02 +0000 http://www.hindawi.com/journals/cri/2012/812127/ This research aims at separation of polyphenols from Jordanian olive mill wastewater which have possible applications in pharmaceutical industry. The phenolic compounds were isolated using silica column chromatography based on using different solvents after extracting the acidified solution with n-hexane and ethyl acetate. The structural elucidation of the separated compounds was achieved using 1H-NMR, 13C-NMR and mass spectrometry. The concentrations of these compounds were determined by GC-MS after derivatization with N, O-bis(trimethylsilyl)trifluoroacetamide (BSTFA). The concentrations of the main isolated phenolic compounds in the Jordanian olive mill wastewater were ferulic acid (93.6 mg/L), trans-cinnamic acid (105.3 mg/L), p-coumaric acid (117.0 mg/L), vanillic acid (128.7 mg/L), caffeic acid (140.4 mg/L), tyrosol (210.6 mg/L), and hydroxytyrosol (315.9 mg/L). Ahmad A. Deeb, Manar K. Fayyad, and Mahmoud A. Alawi Copyright © 2012 Ahmad A. Deeb et al. All rights reserved. Mon, 11 Jun 2012 08:49:55 +0000 http://www.hindawi.com/journals/cri/2012/356216/ A stability-indicating RP-TLC/Densitometry method for analysis of Raloxifene hydrochloride both in bulk material and in tablets was developed and validated. Densitometric analysis of Raloxifene hydrochloride was carried out at 311 nm on TLC aluminium plates precoated with silica gel 60RP-18 F254S as the stationary phase and methanol : water : ammonia (95 : 05 : 0.1v/v) as mobile phase. Raloxifene hydrochloride was well resolved at 𝑅𝑓 0.55 ± 0.02. The linear regression analysis data for the calibration plots showed good linear relationship with 𝑟2=0.9969±0.0015 with respect to peak area in the concentration range 100–600 ng per band. The mean value ± SD of slope and intercept was found to be 15.05±0.44 and 201.9±29.58 with respect to peak area. The limits of detection and quantification were 9.27 ng and 27.10 ng, respectively. Raloxifene hydrochloride was subjected to acid and alkali hydrolysis, oxidation, dry heat, and photodegradation. The drug underwent degradation under basic and oxidation conditions. This indicates that the drug is susceptible to alkali hydrolysis and oxidation. The proposed developed RP-TLC/Densitometry method can be applied for identification and quantitative determination of Raloxifene hydrochloride in bulk material and tablets. A. A. Shirkhedkar, J. K. Rajput, D. K. Rajput, and S. J. Surana Copyright © 2012 A. A. Shirkhedkar et al. All rights reserved. Sun, 10 Jun 2012 09:16:31 +0000 http://www.hindawi.com/journals/cri/2012/806068/ A stability-indicating method has been developed and validated for the quantitative determination of memantine hydrochloride and its nonchromophoric impurities in drug substance and drug product using gas chromatography coupled with flame ionization detector (GC-FID). The stability-indicating nature of the method has been proved by establishing peak purity and confirming the mass balance of all samples by subjecting them to stress conditions like hydrolysis, oxidation, photolysis, and thermal degradation studies. The chromatographic separation was performed on a fused silica capillary (HP-5, 30 meter, 0.32 mm and 0.25 μm film thickness) column. The method validation results indicate that the method has acceptable specificity, accuracy, linearity, precision, robustness, and high sensitivity with detection limits and quantitation limits ranging from 0.001% to 0.01% and 0.004% to 0.03%, respectively. The effectiveness of the technique was demonstrated by analysis of different bulk sample of Memantine hydrochloride. The proposed GC-FID method was also found to be specific and selective for the analysis of commercial formulation samples. Sanjay A. Jadhav, Shashikant B. Landge, Navanath C. Niphade, Saroj R. Bembalkar, and Vijayavitthal T. Mathad Copyright © 2012 Sanjay A. Jadhav et al. All rights reserved. Thu, 07 Jun 2012 12:07:09 +0000 http://www.hindawi.com/journals/cri/2012/573690/ Samuel Carda-Broch, Josep Esteve-Romero, Maria Rambla-Alegre, Maria Jose Ruiz-Angel, Alain Berthod, and Devasish Bose Copyright © 2012 Samuel Carda-Broch et al. All rights reserved. Tue, 29 May 2012 11:24:14 +0000 http://www.hindawi.com/journals/cri/2012/870951/ The use of Ultra Performance Liquid Chromatography (UPLC), with a rapid 5-minute reversed phase isocratic separation on a 1.7 μm reversed-phase packing material to provide rapid ‘‘high throughput’’ support for tramadol hydrochloride (TMH) is demonstrated. A simple, precise and accurate stability-indicating isocratic UPLC method was developed for the determination of TMH in bulk drug and in its tablets. The method was developed using Waters Aquity BEH C18 column (100 mm × 2.1 mm, 1.7 μm) with mobile phase consisting of a mixture of potassium dihydrogen phosphate buffer of pH 2.8 and an equal volume of acetonitrile (60 : 40 v/v). The eluted compound was detected at 226 nm with a UV detector. The standard curve of mean peak area versus concentration showed an excellent linearity over a concentration range 0.5–300 μg mL−1 TMH with regression coefficient (r) value of 0.9999. The limit of detection (S/N =3) was 0.08 μg mL−1 and the limit of quantification (S/N =10) was 0.2 μg mL−1. Forced degradation of the bulk sample was conducted an accordance with the ICH guidelines. Acidic, basic, hydrolytic, oxidative, thermal and photolytic degradation were used to assess the stability indicating power of the method. TMH was found to degrade significantly in acidic, basic and oxidative stress conditions and stable in thermal, hydrolytic and photolytic conditions. Kanakapura B. Vinay, Hosakere D. Revanasiddappa, Cijo M. Xavier, Pavagada J. Ramesh, and Madihalli S. Raghu Copyright © 2012 Kanakapura B. Vinay et al. All rights reserved. Sun, 20 May 2012 09:16:18 +0000 http://www.hindawi.com/journals/cri/2012/162302/ A rapid, sensitive, and reproducible RP-HPLC method was developed for the determination of two constituents in Ammannia multiflora, namely, tetralone-4-O-β-D-glucopyranoside (1) and 4-hydroxy-α-tetralone (2). The samples were separated on a Spherisorb ODS2 column (250×4.6 mm, i.d., 10 μm) and binary elution of water and methanol (2 : 3) with flow rate of 0.8 mL/min at λ 254 nm. The LOD and LOQ were found 0.05 and 0.18 μg/mL for compound 1 and 0.06 and 0.18 μg/mL for compound 2, respectively. All calibration curves showed good linearity (𝑟2>0.999) within test ranges for both the analytes. The RSD values for intra-and inter-day precisions were less than 1.1%. The successful application of the developed method on five different samples revealed an average 0.0206% and 0.7636% (w/w) of compounds 1 and 2, respectively in A. multiflora indicating that the developed LC assay method may be readily utilized as a quality control method for the plant. Harish C. Upadhyay, Ram K. Verma, and Santosh K. Srivastava Copyright © 2012 Harish C. Upadhyay et al. All rights reserved. Mon, 14 May 2012 14:41:18 +0000 http://www.hindawi.com/journals/cri/2012/437075/ An extended-release (ER) niacin and lovastatin fixed-dose combination has been developed for the treatment of primary hypercholesterolemia and mixed dyslipidemia. The purpose of the present study was to examine the drug interaction between niacin and lovastatin after multi-dose oral administration of lovastatin/niacin ER combination in healthy Chinese volunteers. A single-center, randomized, open-label, 5-period crossover study was conducted in thirty healthy volunteers aged 18 to 45 years with a washout period of 8 days. Subjects were randomized to receive multiple doses of treatment A (1 500 mg niacin ER tablet), B (1 20 mg lovastatin tablet), C (1 20 mg lovastatin and 500 mg niacin-ER tablet), D (2 10 mg lovastatin and 350 mg niacin-ER tablets) or E (2 10 mg lovastatin and 500 mg niacin-ER tablets) in 1 of 5 sequences (ABCDE, BCDEA, CDEAB, DEABC, EABCD) per period. Lovastatin, niacin and its metabolites (nicotinuric acid and nicotinamide) were determined in plasma by LC/MS method. Pharmacokinetic parameters were calculated, and least square mean ratios and 90% confidence intervals for 𝐶max and AUC(0–24) were determined for lovastatin/niacin ER versus niacin ER or lovastatin. It revealed that the formulation had no potential drug interaction in healthy Chinese volunteers when the dosage was increased from 500 mg to 1000 mg. Yan-yan Jia, Song Ying, Chen-tao Lu, Jing Yang, Li-kun Ding, Ai-dong Wen, and Yan-rong Zhu Copyright © 2012 Yan-yan Jia et al. All rights reserved. Mon, 14 May 2012 09:41:16 +0000 http://www.hindawi.com/journals/cri/2012/610427/ The purpose of this study is to develop and validate a dissolution test for fluconazole, an antifungal used for the treatment of superficial, cutaneous, and cutaneomucous infections caused by Candida species, in capsules dosage form. Techniques by HPLC and UV first derivative spectrophotometry (UV-FDS) were selected for quantitative evaluation. In the development of release profile, several conditions were evaluated. Dissolution test parameters were considered appropriate when a most discriminative release profile for fluconazole capsules was yielded. Dissolution test conditions for fluconazole capsules were 900 mL of HCl 0.1 M, 37 ± 0.5 °C using baskets with 50 rpm for 30 min of test. The developed HPLC and UV-FDS methods for the antifungal evaluation were selective and met requirements for an appropriate and validated method, according to ICH and USP requirements. Both methods can be useful in the registration process of new drugs or their renewal. For routine analysis application cost, simplicity, equipment, solvents, speed, and application to large or small workloads should be observed. Josilene Chaves Ruela Corrêa, Cristina Duarte Vianna-Soares, and Hérida Regina Nunes Salgado Copyright © 2012 Josilene Chaves Ruela Corrêa et al. All rights reserved. Tue, 10 Apr 2012 13:25:56 +0000 http://www.hindawi.com/journals/cri/2012/564243/ A simple micellar liquid chromatography (MLC) method was developed and validated according to ICH Guidelines for the determination of sesquiterpenic acids (valerenic, hydroxyvalerenic, and acetoxyvalerenic acids) in root and rhizome extract from Valeriana officinalis L. and valerian dry hydroalcoholic extract. Samples were analyzed on Nucleosil C18 column (150mm×4.6mm, 5 μm) using an isocratic mobile phase which consisted of Brij 35 (5% (w/v) aqueous solution; pH 2.3±0.1 by phosphoric acid) and 1-butanol (6% (v/v)); UV detection was at 220 nm. Micellar mobile phase using allows to fully separate valerenic acids within 25 minutes. Linearity for hydroxyvalerenic, acetoxyvalerenic, and valerenic acids was 1.9–27.9, 4.2–63.0, and 6.1–91·3 μg.mL−1, and limit of detection was 0.14, 0.037, and 0.09 μg·mL−1, respectively. Intraday and interday precisions were not less than 2% for all investigated compounds. The proposed method was found to be reproducible and convenient for quantitative analysis of sesquiterpenic acids in valerian root and related preparations. Artem U. Kulikov Copyright © 2012 Artem U. Kulikov. All rights reserved. Tue, 10 Apr 2012 09:06:45 +0000 http://www.hindawi.com/journals/cri/2012/157916/ A simple, sensitive, and selective high-performance liquid chromatographic (HPLC) method has been developed and validated for the analysis of aconitine in marketed ayurvedic taila (oil) formulations containing roots of Aconitum chasmanthum. Chromatography of methanolic extracts of these formulations was performed on C18 (5 μm × 25 cm × 4.6 mm i.d.) column using isocratic mobile phase consisting of (65 : 35% v/v) acetonitrile and buffer solution (aqueous 0.01 M ammonium bicarbonate buffer, adjusted to pH 9.6 using 30% ammonia solution) at a flow rate of 1 mL/min and SPD-10 AVP photodiode array (PDA) UV-Visible detector. The analytical reference, aconitine, was quantified at 238 nm. The retention time of aconitine was about 42.54 min. The linear regression analysis data for the calibration plot showed a good linear relationship with correlation coefficient of 0.9989 in the concentration range of 15 to 90 μg/mL for aconitine with respect to peak area. The limit of detection and limit of quantitation values were found to be 0.03 μg/mL and 0.1 μg/mL respectively. Repeatability of the method was found to be 0.551–1.689 RSD. Recovery values from 97.75 to 99.91% indicate excellent accuracy of the method. The developed HPLC method is accurate and precise and it can be successfully applied for the determination of aconitine in marketed ayurvedic oil formulations containing Aconitum chasmanthum. Nitin Dubey, Nidhi Dubey, and Rajendra Mehta Copyright © 2012 Nitin Dubey et al. All rights reserved. Tue, 27 Mar 2012 14:16:05 +0000 http://www.hindawi.com/journals/cri/2012/421909/ A practical liquid chromatographic method has been developed for the selective determination of the levels of spermine in anchovy sauce after derivatization with 3,5 dinitrobenzoyl chloride. The micellar liquid chromatographic separation proposed here uses a C18 column (125×4.6 mm), followed by detection of spermine derivative at 260 nm. Elution of the analyte was performed using a mobile phase of 0.15 M SDS-4% (v/v) 1-pentanol-pH 7 running under isocratic mode at 25°C. Validation parameters were linearity (2–100 μg/mL, 𝑅2>0.999), detection and quantification limits (0.4 and 1.2 μg/mL, resp.), precision (less than 3.6%), accuracy (93.3–101.1%), and robustness (less than 4.8%). These results are in agreement with the requirements of the FDA guidelines. The proposed method was successfully applied to the monitorization of spermine formation in unsalted and salted fish sauce samples. The suggested methodology was found useful in routine analysis of spermine in fish sauce samples. Mei-Liang Chin-Chen, Maria Rambla-Alegre, Samuel Carda-Broch, Josep Esteve-Romero, and Juan Peris-Vicente Copyright © 2012 Mei-Liang Chin-Chen et al. All rights reserved. Thu, 22 Mar 2012 14:05:07 +0000 http://www.hindawi.com/journals/cri/2012/402635/ Retention in micellar liquid chromatography is highly reproducible and can be modelled using empirical or mechanistic models with great accuracy to predict the retention changes when the mobile phase composition varies (surfactant and organic solvent concentrations), thus facilitating the optimisation of separation conditions. In addition, the different equilibria inside the column among the solute, the mobile phase, and the modified stationary phase by monomers of surfactant have been exhaustively studied. In a sequential strategy, the retention of the solutes is not known a priori, and each set of mobile phases is designed by taking into account the retention observed with previous eluents. By contrast, in an interpretative strategy, the experiments are designed before the optimization process and used to fit a model that will allow the prediction of the retention of each solute. This strategy is more efficient and reliable. The sequential strategy will be inadequate when several local and/or secondary maxima exist, as frequently occurs in chromatography, and may not give the best maximum, that is to say, the optimum. More often than not, the complexity of the mixtures of compounds studied and the relevant modification of their chromatographic behaviour when changing the mobile phase composition requires the use of computer-assisted simulations in MLC to follow the modifications in the chromatograms in detail. These simulations can be done with sound reliability thanks to the use of chemometrics tools. Maria Rambla-Alegre Copyright © 2012 Maria Rambla-Alegre. All rights reserved. Thu, 22 Mar 2012 11:03:42 +0000 http://www.hindawi.com/journals/cri/2012/898520/ Micellar liquid chromatography (MLC) is an efficient alternative to conventional reversed-phase liquid chromatography with hydro-organic mobile phases. Almost three decades of experience have resulted in an increasing production of analytical applications. Current concern about the environment also reveals MLC as an interesting technique for “green” chemistry because it uses mobile phases containing 90% or more water. These micellar mobile phases have a low toxicity and are not producing hazardous wastes. The stationary phase is modified with an approximately constant amount of surfactant monomers, and the solubilising capability of the mobile phase is altered by the presence of micelles, giving rise to a great variety of interactions (hydrophobic, ionic, and steric) with major implications in retention and selectivity. From its beginnings in 1980, the technique has evolved up to becoming in a real alternative in some instances (and a complement in others) to classical RPLC with aqueous-organic mixtures, owing to its peculiar features and unique advantages. The addition of an organic solvent to the mobile phase was, however, soon suggested in order to enhance the low efficiencies and weak elution strength associated with the mobile phases that contained only micelles. Maria Rambla-Alegre Copyright © 2012 Maria Rambla-Alegre. All rights reserved. Sun, 12 Feb 2012 12:14:05 +0000 http://www.hindawi.com/journals/cri/2012/458153/ Implementation of Brij-35, a nonionic surfactant, as a mobile phase for separation of positional isomers is investigated. Chromolith C-18 SpeedROD is used as a stationary phase. The effect of surfactant and organic modifier (propanol) concentration on the separation of some selected isomers is studied and evaluated in terms of linear solvation energy relationship (LSER). Shape selectivity is assessed by α value of sorbic and benzoic acid, which is found to be 1.339 by using mobile phase composed of 0.5% aqueous solutions of Brij-35 and propanol in 9 : 1. Isomers of parabens, nitroanilines, nitrophenols, and quinolinols are successfully separated using mobile phases composed of various percentages of surfactant and propanol. System constants for nonionic MLC using LSER analysis show that hydrogen bond basicity and dipolarity may be major contributors to selectivity, while excess molar refraction helps fine-tuning the separation which also imparts unique selectivity to nonionic surfactants as compared to ionic ones. Najma Memon, Huma I. Shaikh, and Amber R. Solangi Copyright © 2012 Najma Memon et al. All rights reserved. Wed, 08 Feb 2012 09:27:49 +0000 http://www.hindawi.com/journals/cri/2012/809541/ Teresa Kowalska, Hassan Y. Aboul-Enein, Yvan Vander Heyden, Irena Vovk, and Monika Waksmundzka-Hajnos Copyright © 2012 Teresa Kowalska et al. All rights reserved. Mon, 06 Feb 2012 15:39:26 +0000 http://www.hindawi.com/journals/cri/2012/273604/ A simple and sensitive thin-layer chromatographic method has been established for analysis of rasagiline mesylate in pharmaceutical dosage form. Chromatography on silica gel 60 F254 plates with 6 : 1 : 2(v/v/v) butanol-methanol water as mobile phase furnished compact spots at 𝑅𝑓  0.76±0.01. Densitometric analysis was performed at 254 nm. To show the specificity of the method, rasagiline mesylate was subjected to acid, base, neutral hydrolysis, oxidation, photolysis, and thermal decomposition, and the peaks of degradation products were well resolved from that of the pure drug. Linear regression analysis revealed a good linear relationship between peak area and amount of rasagiline mesylate in the range of 100–350 ng/band. The minimum amount of rasagiline mesylate that could be authentically detected and quantified was 11.12 and 37.21 ng/band, respectively. The method was validated, in accordance with ICH guidelines for precision, accuracy, and robustness. Since the method could effectively separate the drug from its degradation products, it can be regarded as stability indicating. Singaram Kathirvel, Suggala Venkata Satyanarayana, and Garikapati Devalarao Copyright © 2012 Singaram Kathirvel et al. All rights reserved. Mon, 06 Feb 2012 13:05:29 +0000 http://www.hindawi.com/journals/cri/2012/130732/ We succeeded in developing the fingerprint of natural product by eastern blotting using monoclonal antibodies. After developing and separating them on a TLC plate, solasodine glycosides are oxidized by NaIO4 and reacted with a protein to give conjugates which are recognized with anti-solamargine monoclonal antibody (MAb). Anti-solamargine MAb having wide cross-reactivity can stain and detect all solasodine glycosides by fingerprint. Different sensitivity between solamargine and solasonine was observed. The detection limit was 1.6 ng of solasonine. The hydrolysed products of solamargine were determined by fingerprint of eastern blotting compared to their Rf values depending on the sugar number. Fingerprint by eastern blotting using anti-ginsenoside Rb1 MAb distinguished the formula containing ginseng prescribed in traditional Chinese medicine. By double-staining of ginsenosides it is possible to suggest that the staining color shows the pharmacological activity, such as the purple bands indicate ginsenosides having stimulation activity, and the blue color indicated compound like ginsenosides possessed the depression affect for the central nervous system (CNS), respectively. Hiroyuki Tanaka, Waraporn Putalun, and Yukihiro Shoyama Copyright © 2012 Hiroyuki Tanaka et al. All rights reserved. Thu, 26 Jan 2012 16:20:03 +0000 http://www.hindawi.com/journals/cri/2012/691509/ This paper describes the application of HPLC and CZE to analyze flavonoids in the leaves of Maytenus ilicifolia and Maytenus aquifolium, which are species widely used in Brazilian folk medicine. The two species showed different flavonoid profiles, but acidic hydrolysis of the Maytenus extracts confirmed that all these compounds are quercetin or kaempferol derivatives. A comparison of the CZE and HPLC profiles of Maytenus extracts showed numerous flavonoid peaks using HPLC. However, the advantages of CZE such as analysis without requiring clean-up and less generation of chemical waste than with HPLC point to the potential of the CZE technique for the quality control (routine analysis) of “espinheira santa” phytopharmaceuticals. Cristina A. Diagone, Renata Colombo, Fernando M. Lanças, and Janete H. Yariwake Copyright © 2012 Cristina A. Diagone et al. All rights reserved.