Simultaneous spectrophotometric determination of pseudoephedrine hydrochloride and ibuprofen in a pharmaceutical preparation using ratio spectra derivative spectrophotometry and multivariate calibration techniques

A Chemometric Strategy in the Development of a RP-UPLC Method for the Quantitative Resolution of a Two-Component Syrup Formulation

A novel chemometric strategy was implemented in the development of a new ultraperformance liquid chromatography method for the quantitative estimation of guaifenesin and pseudoephedrine hydrochloride in a two-component syrup formulation with minimal experimental effort, time and reagent. A full factorial design with three factors was investigated to find optimal working conditions of chromatographic factors (column temperature, flow rate, and 0.1 M H3PO4% in mobile phase) that affect the chromatographic separation. Then, optimum experimental conditions providing adequate separation of the analyzed drug substances within the short runtime were determined. Under optimal experimental conditions, the retention times for guaifenesin and pseudoephedrine hydrochloride were obtained as 0.817 and 1.430 min, respectively. In the optimized RP-UPLC method, chromatographic response was reported as a linear function of concentration between 5.0 and 80.0 μg/mL for guaifenesin and 10.0-90.0 μg/mL for pseudoephedrine hydrochloride. The proposed method was carefully validated and successfully applied to quality control and analysis of a cough syrup preparation containing guaifenesin and pseudoephedrine hydrochloride. Consequently, the proposed reversed-phase ultraperformance liquid chromatography method provided an opportunity to quantify relevant drugs with small amount of reagents and short runtime.

Smart Spectral Processing of Data for the estimation of Commonly Used Over-the-counter (OTC) Co-formulated drug; Pseudoephedrine hydrochloride and Ibuprofen

Oral pharmaceutical preparation containing pseudoephedrine hydrochloride (PSE) and ibuprofen (IBU) is widely prescribed as over- the- counter (OTC) for treatment of common cold-sinus. Development of four precise and accurate spectrophotometric methods are established for the concurrent determination of (PSE) and (IBU)in this preparation exploiting zero and/or ratio spectra. Method I is a dual wavelength method (DW). method II is a ratio difference method (RD), method III is a constant multiplication coupled with spectrum subtraction method (CM-SS) and method IV is a constant center coupled with spectrum subtraction method (CC-SS). While, absorbance correction method (AC) is successfully established for the determination of (IBU) only exploiting zero order absorption spectra. The calibration curves are linear over the concentration range of 100.0-900.0 μg/mL for (PSE) and 200.0-1000.0 μg/mL for (IBU). No separation steps are required for the spectrophotometric procedures which augments their simplicity. Analyzing synthetic mixtures of the cited drugs evaluated the specificity of the applied methods. Validation of the analysis results have been statistically performed confirming the accuracy and reproducibility of the proposed method through recovery studies which were carried out by following ICH guidelines. Thus, the developed methods can be successfully applied routinely in quality control laboratory.

Multicomponent spectrometric analysis of drugs and their preparations

Pharmaceutical preparations may contain a single ingredient or multi-ingredients as well as excipients. In multicomponent systems, specific analytical methods are required to determine the concentrations of individual components in the presence of interfering substances. Ultraviolet and visible spectrometric methods have widely been developed for the analysis of drugs in mixtures and pharmaceutical preparations. These methods are based on ultraviolet and visible multicomponent analysis and chemometrics (multivariate data analysis). The commonly used chemometric methods include principal component analysis (PCA); regression involving classical least squares (CLS), partial least squares (PLS), inverse least squares (ILS), principal component regression (PCR), multiple linear regression (MLR), artificial neural networks (ANNs); soft independent modeling of class anthology (SIMCA), PLS-discriminant analysis (DA); and functional data analysis (FDA). In this chapter, the applications of multicomponent ultraviolet and visible, derivative, infrared and mass spectrometric and spectrofluorimetric methods to the analysis of multi-ingredient pharmaceutical preparations, biological samples and the kinetics of drug degradation have been reviewed. Chemometric methods provide an efficient solution to calibration problems in the analysis of spectral data for the simultaneous determination of drugs in multicomponent systems. These methods facilitate the assessment of product quality and enhance the efficiency of quality control systems.

Spectrometric Smartphone-Based System for Ibuprofen Quantification in Commercial Dosage Tablets

A rapid and portable analytical methodology has been developed for ibuprofen (IBU) quantification in commercial dosage tablets using a spectrometric smartphone-based system. The analytical methodology employs point-of-use approaches both for sample preparation and detection, demonstrating its potential utility for portable quality control of pharmaceutical products. In this work, IBU is dissolved in methanol and then treated with a Co(II) aqueous solution, forming a blue complex which is extractable by dispersive liquid-liquid microextraction. Then, the sample's absorption spectrum is directly measured by a spectrometric smartphone-based system using cartridge made of polyoxymethylene for solvent compatibility. The main experimental factors affecting the dispersive liquid-liquid microextraction of Co-IBU complex were optimized using a multivariate analysis. Under optimized conditions, a working range between 20 and 80 μg mL^-1 was obtained with a correlation coefficient of 0.996 for 5 calibration points. The limit of detection and limit of quantification obtained were 4 and 12 μg mL^-1, respectively. The performance of the proposed methodology was evaluated in commercial tablet dosage forms, and the results demonstrate the ability of the method to determine IBU in samples representative of those used in real-world quality control applications. Recovery values between 97% and 105% were obtained, which are comparable to those obtained via standard titrimetric methodology.

Functionalized Fe3O4 Magnetic Nanoparticle Potentiometric Detection Strategy versus Classical Potentiometric Strategy for Determination of Chlorpheniramine Maleate and Pseudoephedrine HCl

Nanosized adsorbents when used in potentiometric methods of analysis usually show better performance rather than the traditional potentiometric approach; this is attributed to the high specific surface area of the nanomaterial used in addition to the lack of internal diffusion resistance, thus improving their adsorption capacity. In the presented work, a rapid and sensitive potentiometric determination of chlorpheniramine maleate (CPM) and pseudoephedrine hydrochloride (PSE) in pure form, in pharmaceutical preparation, and in biological fluid was developed based on functionalized magnetic nanoparticles (Fe₃O₄). This strategy was compared with the classical potentiometric strategy. Three types of sensors were constructed using phosphotungstic acid (PTA), β-cyclodextrin (β-CD), and β-cyclodextrin-conjugated Fe₃O₄ magnetic nanoparticles for the potentiometric determination of each of CPM and PSE. The prepared sensors were characterized in regards to their composition, life duration, working pH range, and response time. The sensors have demonstrated promising selectivity to CPM and PSE in the presence of pharmaceutical formulation excipients, plasma matrix, and a diversity of both organic and inorganic interfering materials. The developed sensors have displayed good responses. Statistical comparison of the achieved results with a reported method has revealed no significant difference regarding both accuracy and precision.

Use of continuous wavelet transform approach for simultaneous quantitative determination of multicomponent mixture by UV-Vis spectrophotometry

In the present paper, a multicomponent analysis approach based on spectrophotometry method was developed for simultaneous determination of Guaifenesin (GU), Chlorpheniramine (CHL) and Pseudoephedrine (PSE) without any separation steps. The method under study is signal processing method based on Continuous Wavelet Transform (CWT) coupled with zero cross point technique. In this paper, CWT method was tested by synthetic ternary mixtures and was applied to the commercial cough syrup as a real sample and assessed by applying the standard addition technique. For demonstrate the accuracy of the results, other applications of signal processing, such as Derivative Transform (DT), Partial Least Squares (PLS) regression and Principal Components Regression (PCR) were used as comparative methods. Afterwards, the obtained results from analyzing the cough syrup by all methods were compared to the High-Performance Liquid Chromatography (HPLC) as a reference method. One-way analysis of variance test at 95% confidence level showed no significant differences between CWT and other applications.

Simultaneous Liquid Chromatographic Determination of Ebastine with Two Sympathomimetic Drugs Using a Monolithic Column

Ebastine (EBS) has been assayed in its laboratory-prepared co-formulated tablets with either pseudoephedrine hydrochloride (PSU) or phenylephrine hydrochloride (PHR) using isocratic reversed-phase chromatography. Separation was conducted using a 50 mm × 4.6 mm i.d., Chromolith® SpeedROD RP-18 end-capped column at ambient temperature. A mobile phase composed of water:acetonitrile in a ratio of 25:75 having a pH of 3.2, has been utilized at 1 mL/min with UV detection at 254 nm for both EBS and PSU and 274 nm for PHR which in turn increased the sensitivity of the proposed method significantly. Symmetric well-separated peaks resulted in a short chromatographic run; <5 min. The proposed method was subjected to detailed validation procedures and proved to be highly sensitive as shown from limit of quantification values which were 4.7, 39.4 and 10.2 μg/mL for EBS, PSU and PHR, respectively. The proposed method was used to analyze EBS in its laboratory-prepared co-formulated tablets; the obtained results were comparable to those resulting from the reference method.

Preconcentration of codeine in pharmaceutical and human urine samples by multi-walled carbon nanotubes and its spectrophotometric determination

A rapid and efficient solid phase extraction method was established for the preconcentration of codeine prior to its simple determination by spectrophotometry. The extraction process is based on the multi-walled carbon nanotubes (CNTs) containing –COOH functional groups. These CNTs showed a great affinity for the low quantities of codeine in certain condition. Various extraction factors including buffer type, concentration and its pH, ionic buffer, incubation time, and eluent were optimized to achieve high sensitivity. The calibration graph was linear in the codeine concentration range of 0.001–4 mg·L−1, with a detection limit (3s) of 0.4 μg·L−1. The relative standard deviation (RSD %) for the repetitive determination of 0.01, 0.5, and 2 mg·L−1 codeine (n = 5) were 1.56%, 2.01%, and 1.63%, respectively. Furthermore, comparison with other reported methods showed that the presented method has suitable characteristics. Finally the method was successfully used to accurately determine codeine in pharmaceutical and human urine samples.

Evaluating the efficiency of spectral resolution of univariate methods manipulating ratio spectra and comparing to multivariate methods: an application to ternary mixture in common cold preparation

Simple, accurate, and selective methods have been developed and validated for simultaneous determination of a ternary mixture of Chlorpheniramine maleate (CPM), Pseudoephedrine HCl (PSE) and Ibuprofen (IBF), in tablet dosage form. Four univariate methods manipulating ratio spectra were applied, method A is the double divisor-ratio difference spectrophotometric method (DD-RD). Method B is double divisor-derivative ratio spectrophotometric method (DD-RD). Method C is derivative ratio spectrum-zero crossing method (DRZC), while method D is mean centering of ratio spectra (MCR). Two multivariate methods were also developed and validated, methods E and F are Principal Component Regression (PCR) and Partial Least Squares (PLSs). The proposed methods have the advantage of simultaneous determination of the mentioned drugs without prior separation steps. They were successfully applied to laboratory-prepared mixtures and to commercial pharmaceutical preparation without any interference from additives. The proposed methods were validated according to the ICH guidelines. The obtained results were statistically compared with the official methods where no significant difference was observed regarding both accuracy and precision.

Monitoring simultaneous photocatalytic-ozonation of mixture of pharmaceuticals in the presence of immobilized TiO2 nanoparticles using MCR-ALS: Identification of intermediates and multi-response optimization approach

The present study has focused on the degradation of a mixture of three pharmaceuticals, i.e. methyldopa (MDP), nalidixic acid (NAD) and famotidine (FAM) which were quantified simultaneously during photocatalytic-ozonation process. The experiments were conducted in a semi-batch reactor where TiO2 nanoparticles (crystallites mean size 8nm) were immobilized on ceramic plates irradiated by UV-A light in the proximity of oxygen and/or ozone. The surface morphology and roughness of the bare and TiO2-coated ceramic plates were analyzed using scanning electron microscopy (SEM) and atomic force microscopy (AFM). An analytical methodology was successfully developed based on both recording ultraviolet-visible (UV-Vis) spectra during the degradation process and a data analysis using multivariate curve resolution with alternating least squares (MCR-ALS). This methodology enabled the researchers to obtain the concentration and spectral profiles of the chemical compounds which were involved in the process. A central composite design was used to study the effect of several factors on multiple responses namely MDP removal (Y1), NAD removal (Y2) and FAM removal (Y3) in the simultaneous photocatalytic-ozonation of these pharmaceuticals. A multi-response optimization procedure based on global desirability of the factors was used to simultaneously maximize Y1, Y2 and Y3. The results of the global desirability revealed that 8mg/L MAD, 8mg/L NAD, 8mg/L FAM, 6L/h ozone flow rate and a 30min-reaction time were the best conditions under which the optimized values of various responses were Y1=95.03%, Y2=84.93% and Y3=99.15%. Also, the intermediate products of pharmaceuticals generated in the photocatalytic-ozonation process were identified by gas chromatography coupled to mass spectrometry.

Simultaneous monitoring of photocatalysis of three pharmaceuticals by immobilized TiO2 nanoparticles: chemometric assessment, intermediates identification and ecotoxicological evaluation

In this study, the photocatalytic degradation of a mixture of three pharmaceuticals, Metronidazole (MET), Atenolol (ATL) and Chlorpromazine (CPR), was quantified simultaneously during the UV/TiO2 process. The investigated TiO2 was Millennium PC-500 immobilized on ceramic plates by sol-gel based method. The partial least squares modeling was successfully applied for the multivariate calibration of the spectrophotometric data. The central composite design was applied to model and optimize the UV/TiO2 process. Predicted values of removal efficiency were found to be in good agreement with experimental values for MET, ATL and CPR (R(2)=0.947 and Adj-R(2)=0.906, R(2)=0.977 and Adj-R(2)=0.960 and R(2)=0.982 and Adj-R(2)=0.969, respectively). The optimum initial concentration of pharmaceuticals, reaction time and UV light intensity was found to be 10 mg L(-1), 150 min and 38.45 W m(-2), respectively. The main degradation intermediates of pharmaceuticals produced in this process were identified by GC-MS technique. The chronic ecotoxicity of pharmaceuticals was evaluated using aquatic species Spirodela polyrrhiza prior to and after photocatalysis. The TOC results (90% removal after 16 h) and ecotoxicological experiments revealed that the photocatalysis process could effectively mineralize and reduce the ecotoxicity of the pharmaceuticals from their aqueous solutions.

Spectrophotometric studies of reactions between pseudo-ephedrine with different inorganic and organic reagents and its micro-determination in pure and in pharmaceutical preparations

Two simple, sensitive, cheep and reliable spectrophotometric methods are suggested for micro-determination of pseudoephedrine in its pure form and in pharmaceutical preparation (Sinofree Tablets). The first one depends on the drug reaction with inorganic sensitive reagent like molybdate anion in aqueous media via formation of ion-pair mechanism. The second one depends on the drug reaction with π-acceptor reagent like DDQ in non-aqueous media via formation of charge transfer complex. These reactions were studied under various conditions and the optimum parameters were selected. Under proper conditions the suggested procedures were successfully applied for micro-determination of pseudoephedrine in pure and in Sinofree Tablets without interference from excepients. The values of SD, RSD, recovery %, LOD, LOQ and Sandell sensitivity refer to the high accuracy and precession of the applied procedures. The results obtained were compared with the data obtained by an official method, referring to confidence and agreement with DDQ procedure results; but it referred to the more accuracy of the molybdate data. Therefore, the suggested procedures are now successfully being applied in routine analysis of this drug in its pharmaceutical formulation (Sinofree) in Saudi Arabian Pharmaceutical Company (SPIMACO) in Boridah El-Qaseem, Saudi Arabia instead of imported kits had been previously used.

A novel spectrofluorimetric method for the assay of pseudoephedrine hydrochloride in pharmaceutical formulations via derivatization with 4-chloro-7-nitrobenzofurazan

A new highly sensitive and specific spectrofluorimetric method has been developed to determine a sympathomimetic drug pseudoephedrine hydrochloride. The present method was based on derivatization with 4-chloro-7-nitrobenzofurazan in phosphate buffer at pH 7.8 to produce a highly fluorescent product which was measured at 532 nm (excitation at 475 nm). Under the optimized conditions a linear relationship and good correlation was found between the fluorescence intensity and pseudoephedrine hydrochloride concentration in the range of 0.5-5 µg mL(-1). The proposed method was successfully applied to the assay of pseudoephedrine hydrochloride in commercial pharmaceutical formulations with good accuracy and precision and without interferences from common additives. Statistical comparison of the results with a well-established method showed excellent agreement and proved that there was no significant difference in the accuracy and precision. The stoichiometry of the reaction was determined and the reaction pathway was postulated.

Spectrophotometric determination of certain CNS stimulants in dosage forms and spiked human urine via derivatization with 2,4-Dinitrofluorobenzene

A new spectrophotometric method is developed for the determination of phenylpropanolamine HCl (PPA), ephedrine HCl (EPH) and pseudoephedrine HCl (PSE) in pharmaceutical preparations and spiked human urine. The method involved heat-catalyzed derivatization of the three drugs with 2,4-dinitrofluorobenzene (DNFB) producing a yellow colored product peaking at 370 nm for PPA and 380 nm for EPH and PSE, respectively.

The absorbance concentration plots were rectilinear over the range of 2-20 for PPA and 1-14 μg/mL for both of EPH and PSE, respectively. The limit of detection (LOD) values were 0.20, 0.13 and 0.20 μg/mL for PPA, EPH and PSE, respectively and limit of quantitation (LOQ) values of 0.60 and 0.40 and 0.59 μg/mL for PPA, EPH and PSE, respectively. The analytical performance of the method was fully validated and the results were satisfactory. The proposed method was successfully applied to the determination of the three studied drugs in their commercial dosage forms including tablets, capsules and ampoules with good percentage recoveries. The proposed method was further applied for the determination of PSE in spiked human urine with a mean percentage recovery of 108.17 ± 1.60 for (n = 3). Statistical comparison of the results obtained with those of the comparison methods showed good agreement and proved that there was no significant difference in the accuracy and precision between the two methods. The mechanism of the reaction pathway was postulated.

Simultaneous estimation of ramipril, acetylsalicylic acid and atorvastatin calcium by chemometrics assisted UV-spectrophotometric method in capsules

In the present work, three different spectrophotometric methods for simultaneous estimation of ramipril, aspirin and atorvastatin calcium in raw materials and in formulations are described. Overlapped data was quantitatively resolved by using chemometric methods, viz. inverse least squares (ILS), principal component regression (PCR) and partial least squares (PLS). Calibrations were constructed using the absorption data matrix corresponding to the concentration data matrix. The linearity range was found to be 1-5, 10-50 and 2-10 μg mL-1 for ramipril, aspirin and atorvastatin calcium, respectively. The absorbance matrix was obtained by measuring the zero-order absorbance in the wavelength range between 210 and 320 nm. A training set design of the concentration data corresponding to the ramipril, aspirin and atorvastatin calcium mixtures was organized statistically to maximize the information content from the spectra and to minimize the error of multivariate calibrations. By applying the respective algorithms for PLS 1, PCR and ILS to the measured spectra of the calibration set, a suitable model was obtained. This model was selected on the basis of RMSECV and RMSEP values. The same was applied to the prediction set and capsule formulation. Mean recoveries of the commercial formulation set together with the figures of merit (calibration sensitivity, selectivity, limit of detection, limit of quantification and analytical sensitivity) were estimated. Validity of the proposed approaches was successfully assessed for analyses of drugs in the various prepared physical mixtures and formulations.

Design and optimization of a chemometric-assisted spectrophotometric determination of telmisartan and hydrochlorothiazide in pharmaceutical dosage form

Two chemometric methods were developed for the simultaneous determination of telmisartan and hydrochlorothiazide. The chemometric methods applied were principal component regression (PCR) and partial least square (PLS-1). These approaches were successfully applied to quantify the two drugs in the mixture using the information included in the UV absorption spectra of appropriate solutions in the range of 200-350 nm with the intervals Δλ = 1 nm. The calibration of PCR and PLS-1 models was evaluated by internal validation (prediction of compounds in its own designed training set of calibration) and by external validation over laboratory prepared mixtures and pharmaceutical preparations. The PCR and PLS-1 methods require neither any separation step, nor any prior graphical treatment of the overlapping spectra of the two drugs in a mixture. The results of PCR and PLS-1 methods were compared with each other and a good agreement was found.

Simultaneous spectrophotometric determination of losartan potassium, amlodipine besilate and hydrochlorothiazide in pharmaceuticals by chemometric methods

In the present work, four different spectrophotometric methods for simultaneous estimation of losartan potassium, amlodipine besilate and hydrochlorothiazide in raw materials and in formulations are described. Overlapped data was quantitatively resolved by using chemometric methods, classical least squares (CLS), multiple linear regression (MLR), principal component regression (PCR) and partial least squares (PLS). Calibrations were constructed using the absorption data matrix corresponding to the concentration data matrix, with measurements in the range of 230.5-350.4 nm (Δλ = 0.1 nm) in their zero order spectra. The linearity range was found to be 8-40, 1-5 and 3-15 μg mL-1 for losartan potassium, amlodipine besilate and hydrochlorothiazide, respectively. The validity of the proposed methods was successfully assessed for analyses of drugs in the various prepared physical mixtures and in tablet formulations.

Properties of ibuprofen ion-selective electrodes based on the ion pair complex of tetraoctylammonium cation

Ibuprofen membrane electrodes based on different plasticizers: diisobutyl phthalate (DIBP), o-nitrophenyloctyl ether (o-NPOE), dioctyl sebacate (DOS) and tetraoctylammonium 2-(4-isobutylphenyl)propionate were prepared. All electrodes show: a near Nernstian slope of characteristic (58.3–60.9 mV decade−1) in the measurement range (10−4–10−1 mol L−1), limit of detection (5.0×10−5 mol L−1), really long lifetime (12 months), dependence of the electrode potential on pH (5.5–9.0), reproducibility of potential (0.6–1.2 mV) and selectivity coefficients in relation to some organic and inorganic anions. The electrodes were applied for the determination of ibuprofen in tablets by the calibration curve method and the standard addition method.

Quantitative determination of hydrate content of theophylline powder by chemometric X-ray powder diffraction analysis

The purpose of this study was to establish a calibration model to predict the hydrate content in powder materials consisting of anhydrate (theophylline anhydrate (THA)) and theophylline monohydrate (THM) by using various kinds of X-ray powder diffraction (XRPD) analytical methods. XRPD profiles were measured five times each for 11 standard samples containing of THA and THM. THM content in the standard samples was evaluated based on XRPD profiles by the diffraction peak height and area methods, and the Wakelin's and principal component regression (PCR) methods, respectively. Since THA and THM were cube- and rod-shaped particles, the standard samples consisted of THA and THM showed crystal orientation due to THM crystal shape. THA showed reproducible XRPD profiles, but THM showed fluctuating intensities in some specific peaks in the profiles. The linear calibration models were evaluated based on calibration XRPD datasets of the standard materials by various methods. In the result based on validation XRPD datasets, the order of the mean bias and the mean accuracy were peak height > peak area > Wakelin's > PCR, indicating that PCR was the best method to correct sample crystal orientation. The effectiveness of the PCR method in construction of calibration models was discussed by a scientific approach based on regression vectors.

Determination of lamivudine and stavudine in pharmaceutical preparations using chemometrics-assisted spectrophotometry

A simple chemometrics-assisted spectrophotometric method for the simultaneous determination of lamivudine and stavudine in pharmaceutical tablets is described. The UV absorption spectra of the studied drugs, in the range of 200-310 nm, showed a considerable degree of spectral overlapping ([Di ](0.5) = 94.9%). Resolution of the mixture has been accomplished by using classical least-squares regression analysis (CLS) and principle components regression analysis methods (PCR). Beer's law was obeyed for both drugs in the general concentration ranges of 2-12 and 3-15 μg ml(-1) for lamivudine and stavudine, respectively. The proposed methods were successfully applied for the determination of the two drugs in laboratory prepared mixtures. The overall recoveries percent were found 98.58 ± 1.53-101.30 ± 1.35 (CLS) and 98.62 ± 1.65-101.13 ± 1.04 (PCR) for lamivudine and 98.43 ± 1.62-99.42 ± 1.55 (CLS) and 98.23 ± 1.97-101.20 ± 1.79 (PCR) for stavudine, respectively. The commercial tablets percentage content was found 98.10 ± 2.5-102.47 ± 2.94 (CLS) and 99.12 ± 1.71-100.92 ± 1.54 (PCR) for lamivudine and 96.00 ± 2.94-98.17 ± 1.72 (CLS) and 97.40 ± 1.55-97.80 ± 1.92 (PCR) for stavudine, respectively. Good percentage recoveries and proper statistical data obtained with both the laboratory prepared mixtures and the commercial tablets proved the suitability and efficiency of the proposed procedures for routine analysis and quality control purposes with quite satisfactory precision. A comparison of the obtained results from CLS and PCR were also performed with those obtained from reported method. The obtained F- and t-values obtained indicating no significant differences between the results of the proposed and reported methods.

Simultaneous spectrophotometric determination of paracetamol, ibuprofen and caffeine in pharmaceuticals by chemometric methods

In this study, the simultaneous determination of paracetamol, ibuprofen and caffeine in pharmaceuticals by chemometric approaches using UV spectrophotometry has been reported as a simple alternative to using separate models for each component. Spectra of paracetamol, ibuprofen and caffeine were recorded at several concentrations within their linear ranges and were used to compute the calibration mixture between wavelengths 200 and 400 nm at an interval of 1 nm in methanol:0.1 HCl (3:1). Partial least squares regression (PLS), genetic algorithm coupled with PLS (GA-PLS), and principal component-artificial neural network (PC-ANN) were used for chemometric analysis of data and the parameters of the chemometric procedures were optimized. The analytical performances of these chemometric methods were characterized by relative prediction errors and recoveries (%) and were compared with each other. The GA-PLS shows superiority over other applied multivariate methods due to the wavelength selection in PLS calibration using a genetic algorithm without loss of prediction capacity. Although the components show an important degree of spectral overlap, they have been determined simultaneously and rapidly requiring no separation step. These three methods were successfully applied to pharmaceutical formulation, capsule, with no interference from excipients as indicated by the recovery study results. The proposed methods are simple and rapid and can be easily used in the quality control of drugs as alternative analysis tools.

High performance thin layer chromatographic method for simultaneous estimation of Ibuprofen and pseudoephedrine hydrochloride

High performance thin layer chromatographic method is developed for simultaneous estimation of ibuprofen and pseudoephedrine hydrochloride in tablets. Silica gel 60F(254) plates were used as stationary phase and t.butanol: ethyl acetate: glacial acetic acid: water (7:4:2:2 v/v) as mobile phase. Wavelength selected for analysis was 254 nm. Percent estimation of ibuprofen and pseudoephedrine hydrochloride was found to be 99.56% and 98.77%, respectively. Percent recovery for both the drugs was found in the range of 98.27% to 100.91%, respectively.

Determination of ibuprofen in pharmaceutical formulations using time-resolved terbium-sensitized luminescence

A sensitive and specific luminescence method for the determination of ibuprofen (IB) in pharmaceutical formulations in aqueous solution is described. The method is based on the luminescence sensitization of terbium (Tb(3+)) by formation of ternary complex with IB in the presence of tri-n-octylphosphine oxide (TOPO) and Tween-20 as surfactant. The luminescence signal for Tb-IB-TOPO is monitored at lambda(ex) = 229 nm and lambda(em) = 545 nm. Optimum conditions for the formation of the complex in aqueous system, were 16 mmol/L TRIS buffer, pH 5.7, TOPO 200 micromol/L and 15 micromol/L of Tb(3+), which allows for the determination of 9.7 x 10(-7) - 9.7 x 10(-6) mol/L IB with a detection limit of 1.2 x 10(-7) mol/L. The relative standard deviations of the method were <1.4%, indicating excellent reproducibility. The proposed method was successfully applied for the assays of IB in pharmaceutical formulations with average recoveries of 100.3-102.5%.

Simultaneous Quantitative Resolution of Atorvastatin Calcium and Fenofibrate in Pharmaceutical Preparation by Using Derivative Ratio Spectrophotometry and Chemometric Calibrations

In the present work, five different spectrophotometric techniques for simultaneous determination of formulations containing atorvastatin calcium (ATOR) and fenofibrate (FENO) in various combinations are described. In ratio spectra derivative spectrophotometry, analytical signals were measured at wavelengths corresponding to either maximums or minimums for both drugs in first derivative spectra of ratio spectra obtained by using either spectrum as divisor. For the remaining four methods using chemometric techniques, namely, classical least squares (CLS), inverse least squares (ILS), principal component regression (PCR) and partial least squares (PLS), the calibrations were constructed by using the absorption data matrix corresponding to the concentration data matrix, with measurements in the range of 231 - 310 nm (Deltalambda = 1 nm) in their zero-order spectra. The linearity range was found to be 4 - 22 and 2 - 20 microg/ml for ATOR and FENO, respectively. The validity of the proposed methods was successfully assessed for analyses of both drugs in laboratory-prepared mixtures and in commercial tablet formulations.

Direct chemiluminescence determination of ibuprofen by the enhancement of the KMnO4–sulphite reaction

A simple, rapid, flow-injection chemiluminescence (CL) method is described for the determination of ibuprofen. A strong CL signal was detected when a mixture of the analyte and sulphite was injected into acidic KMnO(4). The CL signal is proportional to the concentration of ibuprofen in the range 0.1-10.0 mg/L. The detection limit is 0.02 mg/L ibuprofen, the relative standard deviation is 1.8% (0.5 mg/L ibuprofen; n = 11) and the sample measurement frequency is 120/h. The proposed method was successfully applied to the determination of ibuprofen in pharmaceutical preparations and in spiked urine samples. The mechanism of the CL reaction is also discussed.

Construction and Performance Characterization of Ionselective Electrodes for Potentiometric Determination of Pseudoephedrine Hydrochloride Applying Batch and Flow Injection Analysis Techniques

New pseudoephedrine selective electrodes have been constructed of the conventional polymer membrane type by incorporation of pseudoephedrine-phosphotungstate (PE-PT) or pseudoephedrine-silicotungstate (PE-SiT) ion-associates in a poly vinyl chloride (PVC) membrane plasticized with dibutyl phthalate (DBP). The electrodes were fully characterized in terms of the membrane composition, temperature, and pH. The electrodes exhibited mean slopes of calibration graphs of 57.09 and 56.10 mV concentration decade(-1) of PECl at 25 degrees C for (PE-PT) and (PE-SiT) electrodes, respectively. The electrodes showed fast, stable, and near-Nernstian response over the concentration ranges 6.31 x 10(-6)-1.00 x 10(-2) and 5.00 x 10(-5)-1.00x10(-2) M in the case of PE-PT applying batch and flow injection (FI) analysis, respectively, and 1.00 x 10(-5)-1.00 x 10(-2) and 5.00 x 10(-5)-1.00x10(-2) M in the case of PE-SiT for batch and FI analysis system, respectively. Detection limit was 5.01x 10(-6) M for PE-PT electrode and 6.31x10(-6) M for PE-SiT electrode. The electrodes were successfully applied for the potentiometric determination of pseudoephedrine hydrochloride (PECl) in pharmaceutical preparations with mean recovery 101.13 +/- 0.85% and 100.77+0.79% in case of PE-PT applying batch and flow injection systems, respectively, and 100.75+0.85% and 100.79 +/- 0.77% in case of PE-SiT for batch and flow injection systems, respectively. The electrodes exhibited good selectivity for PECl with respect to a large number of inorganic cations, sugars and amino acids.

Determination of ibuprofen and flurbiprofen in pharmaceuticals by capillary zone electrophoresis

Capillary zone electrophoresis with spectrophotometric detection was used for the determination of ibuprofen (IB) and flurbiprofen (FL) in pharmaceuticals. The separation was carried out in a fused silica capillary (60 cm x 100 microm i.d. effective length 45 cm) at 30 kV with UV detection at 232 nm. The optimized background electrolyte was 20mM N-(2-acetamido)-2-aminoethanesulfonic acid (ACES) with 20mM imidazole and 10mM alpha-cyclodextrin of pH 7.3. 2-Naphthoxyacetic acid was used as internal standard. A single analysis took less than 5 min. Rectilinear calibration ranges were 2-500 mg l(-1) for IB and 1-60 mg l(-1) for FL. The relative standard deviations (R.S.D.) values (n=6) were 1.53% for IB and 1.29% for FL (for 200 mg l(-1) IB and 10 mg l(-1) FL). This validated method has been successfully applied for the routine analysis of 10 commercially available pharmaceutical preparations (syrup, tablets, cream and gel).

Chemometric Determination of Naproxen Sodium and Pseudoephedrine Hydrochloride in Tablets by HPLC

A new chemometric determination by high-performance liquid chromatography (HPLC) with photodiode array (PDA) detection was implemented for the simultaneous determination of naproxen sodium and pseudoephedrine hydrochloride in tablets. Three chemometric calibration techniques, classical least squares (CLS), principle component regression (PCR) and partial least squares (PLS) were applied to the peak area at multiwavelength PDA detector responses. The combinations of HPLC with chemometric calibration techniques were called HPLC-CLS, HPLC-PCR and HPLC-PLS. For comparison purposes the HPLC method called the classic HPLC method was used to confirm the results obtained from combined HPLC-chemometric calibration techniques. A good chromatographic separation between two drugs with losartan potassium as an internal standard was achieved using a Waters Symmetry C18 Column 5 microm 4.6+/-250 mm and a mobile phase containing 0.2 M acetate buffer and acetonitrile (v/v, 40:60). The multiwavelength PDA detection was measured at five different wavelengths. The chromatograms were recorded as a training set in the mobile phase. Three HPLC-chemometric calibrations and the classic-HPLC method were used to test the synthetic mixtures of naproxen sodium and pseudoephedrine hydrochloride in the presence of the internal standard. The HPLC-chemometric approaches were applied to real samples containing drugs of interest. The experimental results obtained from HPLC-chemometric calibrations were compared with those obtained by a classic HPLC method.

Separation and determination of pseudoephedrine, dextromethorphan, diphenhydramine and chlorpheniramine in cold medicines by nonaqueous capillary electrophoresis

An easy, rapid and simple nonaqueous capillary electrophoresis (NACE) method was developed for the identification and determination of four basic nitrogenous compounds, i.e. pseudoephedrine (PE), dextromethorphan (DXM), diphenhydramine (DHM) and chlorpheniramine (CLP). The most suitable running buffer was composed of 40 mM ammonium acetate, 10% acetonitrile (ACN) in methanol with a fused-silica capillary column (47 cm x 75 microm i.d.), 25 kV applied voltage and 25 degrees C capillary temperature. The calibration curves revealed linear relationships between the peak area for each analyte and its concentration (correlation coefficients: 0.9993 for PE, 0.9971 for DXM, 0.9991 for DHM, and 0.9995 for CLP, respectively). The relative standard deviations of the migration time and peak area of the four compounds were 0.37, 3.90, 0.73 and 0.68, and 2.80, 3.50, 1.60 and 3.70%, respectively. The method was successfully applied to determine the four compounds in five cold medicines, the recoveries of the four constituents ranging between 91 and 109%.

Ratio spectra derivative spectrophotometry for the determination of furosemide and spironolactone in a capsule formulation

The determination of furosemide and spironolactone in a capsule formulation has been investigated using techniques such as Vierordt's method and derivative spectroscopy dA/d lambda and d2A/d lambda2 applying the zero-crossing technique following reported methods. In our hands, using standard mixtures, these methods gave unreliable results. We have therefore investigated the use of ratio spectra derivative spectrophotometry for this determination. The technique of ratio spectra derivative spectrophotometry was developed in 1990, and has recently been used for a number of analyses of co-formulated products. The method was applied to the analysis of standard mixtures of the two drugs and the combined contents of 20 capsules resulting in values (mean +/- standard deviation) of 102.1 +/- 1.9% and 101.4 +/- 4.0% of the stated content for furosemide and spironolactone, respectively. Similarly, the analysis of individual capsules resulted in values of 101.5 +/- 1.6% and 102.2 +/- 1.4% of the stated content for furosemide and spironolactone, respectively.

Recent Developments of Derivative Spectrophotometry and Their Analytical Applications

Articles about the development of derivative spectrophotometric methods and analytical applications of derivative spectrophotometry (DS) published in the last nine years (since 1994) are reviewed.