Browsing by Author "Dinç, E"

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Citation - WoS: 72
Citation - Scopus: 81
An Application of Derivative and Continuous Wavelet Transforms To the Overlapping Ratio Spectra for the Quantitative Multiresolution of a Ternary Mixture of Paracetamol, Acetylsalicylic Acid and Caffeine in Tablets
(Elsevier Science Bv, 2005) Özdemir, A; Baleanu, D; Dinç, E
Quantitative multi resolution of tablets and ternary mixtures of paracetamol (PAR), acetylsalicylic acid (ASP) and caffeine (CAF) having strongly overlapping spectra was accomplished by two graphical transform methods as ratio spectra first derivative-zero crossing and ratio spectra-continuous wavelet transform-zero crossing (ratio spectra CWT-zero crossing) methods. In this study, ratio spectra derivative-zero crossing and ratio spectra CWT-zero crossing methods are based on the use of transformed signals of the ratio spectra and their calibration graphs were obtained by measuring the dA/dlambda and CWT amplitudes of the ratio spectra corresponding to zero crossing points. For the comparison purpose. PLS calibration method was applied to predict the content of the same mixtures containing the subject active Compounds. The obtained calibrations were tested by using the synthetic mixtures and standard addition technique and they applied to the simultaneous determination of PAR, ASP and CAF in commercial pharmaceutical preparation. The obtained results were statistically compared with each other as well as those obtained by HPLC method and they showed good agreement. (C) 2004 Published by Elsevier B.V.
Citation - WoS: 56
Citation - Scopus: 56
Application of the Wavelet Method for the Simultaneous Quantitative Determination of Benazepril and Hydrochlorothiazide in Their Mixtures
(Aoac int, 2004) Baleanu, D; Dinç, E
The discrete and continuous wavelet transforms were applied to the overlapping signal analysis of the ratio data signal for simultaneous quantitative determination of the title subject compounds in samples. The ratio spectra data of the binary mixtures containing benazepril (BE) and hydrochlorothiazide (HCT) were transferred as data vectors into the wavelet domain. Signal compression, followed by a 1-dimension continuous wavelet transform (CWT), was used to obtain coincident transformed signals for pure BE and HCT and their mixtures. The coincident transformed amplitudes corresponding to both maximum and minimum points allowed construction of calibration graphs for each compound in the binary mixture. The validity of CWT calibrations was tested by analyzing synthetic mixtures of the investigated compounds, and successful results were obtained. All calculations were performed within EXCEL, C++, and MATLAB6.5 softwares. The obtained results indicated that our approach was flexible and applicable for the binary mixture analysis.
Citation - WoS: 53
Citation - Scopus: 58
An Approach To Quantitative Two-Component Analysis of a Mixture Containing Hydrochlorothiazide and Spironolactone in Tablets by One-Dimensional Continuous Daubechies and Biorthogonal Wavelet Analysis of Uv-Spectra
(Taylor & Francis inc, 2003) Baleanu, D; Üstündag, Ö; Dinç, E
In this study a new method of quantitative two-component analysis of a mixture of hydrochlorothiazide (HCT) and spironolactone (SP) in the presence of strongly overlapping signals was achieved by using one-dimensional continuous wavelet analysis. This new method was built on the simultaneous use of both continuous wavelet transform and the zero crossing technique for the quantitative resolution of this binary mixture. A series of solutions, in the concentration range of 2-22 mg/ml for both compounds, in methanol and 0.2 M sodium acetate buffer, pH = 5 (20:80), were considered. The absorption spectra of the standard solutions were recorded in the wavelength range of 215-330 nm. To apply our methods we selected 400 points from the absorption spectra and we subjected the corresponding signal to Daubechies2 (DAUB2) and Biorthogonal1.5 (BIOR1.5) one-dimensional wavelet transform. In the transformed signals, the amplitude of HCT was measured at the position of a zero crossing point of SP and vice versa. Thus simple linear regression analysis can be applied to establish calibrations for both components. These calibrations were validated with synthetic mixtures of HCT and SP. MATLAB 6.5 software was used for one-dimensional wavelet analysis, and the basic concepts about wavelet method are briefly explained. The method developed in this paper is rapid, easy to apply, inexpensive and it is suitable for analysis of the overlapping signals of compounds in their mixtures without any chemical pre-treatment.
Citation - WoS: 24
Citation - Scopus: 28
Chemometric Approach To Simultaneous Chromatographic Determination of Paracetamol and Chlorzoxazone in Tablets and Spiked Human Plasma
(Taylor & Francis inc, 2006) Ozdemir, A; Aksoy, H; Baleanu, D; Dinç, E
New chemometric approaches were introduced into the high performance liquid chromatographic (HPLC) determination of chlorzoxazone (CZX) and paracetamol (PAR) in the tablets and spiked human plasma. These chemometric approaches contain the application of classical least squares (CLS), principle component regression (PCR), and partial least squares (PLS) calibrations to the multiwavelength HPLC peak area obtained by plotting the chromatograms at the five wavelengths. The multichromatograms were obtained by using the photodiode array detector at 225 (A), 240 (B), 255 (C), 270 (D), and 285 (E) nm. The algorithms of CLS, PCR, and PLS were applied to the multichromatogram data to construct the HPLC-CLS, HPLC-PCR, and HPLC-PLS calibrations. A mixture of acetonitrile and 0.1 M ammonium carbonate (60:40, v/v) on a Waters Symmetry (R) trademark C18 Column 5 mu m 4.6 x 250 mm at a flow rate of 0.8 mL/min was used as a mobile phase to separate and determine CZX and PAR in samples. Hydrochlorothiazide (IS) was used as an internal standard in this chromatographic separation. The HPLC chemometric calibrations were successfully applied to the quantitative analysis of the investigated drugs in commercial pharmaceutical preparation and spiked human plasma samples with high precision and accuracy.
Chemometric Calibration Based on the Wavelet Transform for the Quantitative Resolution of Two-Colorant Mixtures
(Editura Acad Romane, 2005) Baleanu, Dumitru; Dinç, E; Baleanu, D; Taş, Kenan; Üstundag, O; Tas, K; Matematik
In this study we proposed a wavelet transform (WT) followed by two chemometric techniques for the quantitative determination of sunset yellow (SUN) and tartrazine (TAR) in their market samples. Absorbances of the concentration set formed by TAR and SUN mixtures were measured between 335-575 nm at 480 points with 0.5 nm intervals and their absorbance values as absorbance data vectors were transferred into the wavelets domain. A continuous wavelet transform (CWT) was applied, to the absorbance data. The obtained CWT-coefficients (x-block) and concentration set (y-block) were used for the construction of the principal component regression (VCR) and partial least squares (PLS) calibrations. Good results were reported for the application of the combining wavelets and chemometric tools in the determination of colorants in samples.
Citation - WoS: 31
Citation - Scopus: 40
Chemometric Determination of Naproxen Sodium and Pseudoephedrine Hydrochloride in Tablets by Hplc
(Pharmaceutical Soc Japan, 2006) Özdemir, A; Aksoy, H; Üstündag, Ö; Baleanu, D; Dinç, E
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 chernometric 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 (R) C18 Column 5 mu m 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.
Citation - WoS: 34
Chemometric Quantitative Analysis of Pyridoxine Hcl and Thiamine Hcl in a Vitamin Combination by Principal Component Analysis, Classical Least Squares, and Inverse Least Squares Techniques
(Marcel dekker inc, 2001) Baleanu, D; Onur, F; Dinç, E
Three chemometric techniques were described for the analysis of pyridoxine hydrochloride and thiamine hydrochloride within a vitamin combination in the presence of spectral interferences. For these techniques, the training set was prepared by using synthetic mixtures containing two vitamins in multiple possible combinations for the range of 8-40 mu /mL in 0.1 M HCl. The absorbance values for the training set were obtained by direct measurements at 18 wavelengths in the region 222-305 nm for the zero order spectra. The numerical values were calculated by using the 'Maple V' software. Mean recoveries and relative standard deviations for the principal component analysis, classical least squares and inverse least squares techniques were found as 100.7% and 0.95%; 100.5% and 1.38% and, 99.3% and 1.04 for pyridoxine hydrochloride; and 99.7% and 1.03%; 99.1% and 1.05% and, 99.6% and 1.58% for thiamine hydrochloride, respectively. These three chemometric techniques were successfully applied to vitamin tablets marketed in Turkey. The results were compared with each other and good coincidence was observed.
Citation - WoS: 16
Citation - Scopus: 16
Comparative Application of Wavelet Approaches To Absorption and Ratio Spectra for the Simultaneous Determination of Diminazene Aceturate and Phenazone in Veterinary Granules for Injection
(Govi-verlag Pharmazeutischer verlag Gmbh, 2005) Dinç, E; Baleanu, Dumitru; Kanbur, M; Baleanu, D; Matematik
A comparison of two wavelet approaches, Daubechies and reverse Biorthogonal, is described for the quantitative resolution of a binary mixture of diminazene aceturate (DIMA) and phenazone (PHE) in veterinary granules for injection without any chemical separation. These two approaches were specified as db4 (a = 180) and rbior3.7 (a = 125) respectively, after testing the signal analysis parameters for the overlapping absorption spectra and ratio spectra. In the first step db4 (a = 180) was applied to the original absorbance data vector of DIMA and PHE. In the second step rbio3.7 (a = 125) was applied to the ratio spectra data vectors of DIMA using the divisor PHE. The same approach was also subjected to the ratio spectra of PHE using the divisor DIMA. The db4 (a = 180) and rbior3.7 (a = 125) calibration graphs were constructed using the transformation values obtained in the wavelet domain. In the method validation, the wavelet calibration functions were tested using synthetic mixtures and the standard addition technique. The simultaneous quantitative analysis of DIMA and PHE in the commercial veterinary preparation was achieved by the elaborated methods. The assay results were compared with each other and good agreement was observed.
Citation - WoS: 51
Citation - Scopus: 56
Comparative Study of the Continuous Wavelet Transform, Derivative and Partial Least Squares Methods Applied To the Overlapping Spectra for the Simultaneous Quantitative Resolution of Ascorbic Acid and Acetylsalicylic Acid in Effervescent Tablets
(Elsevier Science Bv, 2005) Ozdemir, A; Baleanu, D; Dinç, E
The simultaneous spectrophotometric determination of ascorbic acid (AA) and acetylsalicylic acid (ASA) in effervescent tablets in the presence of the overlapping spectra was accomplished by the continuous wavelet transform (CWT), derivative spectrophotometry (DS) and partial least squares (PLS) approaches without using any chemical pre-treatment. CWT and DS calibration equations for AA and ASA were obtained by measuring the CWT and DS amplitudes corresponding to zero-crossing points of spectra obtained by plotting continuous wavelet coefficients and first-derivative absorbance values versus the wavelengths, respectively. The PLS calibration was constructed by using the concentration set and its full absorbance data consisting of 850 points from 220 to 305 urn in the range of 210-310 nun. These three methods were tested by analyzing the synthetic mixtures of the above drugs and they were applied to the real samples containing two commercial pharmaceutical preparations of subjected drugs. A comparative study was carried out by using the experimental results obtained from three analytical methodologies and precise and accurate results were obtained. (c) 2004 Published by Elsevier B.V.
Citation - WoS: 13
Citation - Scopus: 14
Continuous Wavelet Transformation Applied To the Simultaneous Quantitative Analysis of Two-Component Mixtures
(Govi-verlag Pharmazeutischer verlag Gmbh, 2004) Dinç, E; Baleanu, Dumitru; Baleanu, D; Üstündag, Ö; Aboul-Enein, HY; Matematik
In this paper we developed a graphical method based on Haar (HA) and Mexican (MEX) one-dimensional continuous wavelet transforms and we applied it to a mixture of hydrochlorothiazide (HCT) and spironolactone (SP) in the presence of strongly overlapping signals. Keeping in mind to obtain an appropriately transformed spectrum, we tested several values of the scaling parameter a and the point number of the analysed spectrum in the concentration range of 2-22 mug/ml for both active compounds. The optimal values of the scale parameters and the corresponding frequencies were found to be a = 32 and 0.031 for HA and a = 30 and 0.008 for MEX corresponding to 400 points. HA and MEX methods based on a zero crossing technique were applied to the analysed signal and their regression lines at the selected points were obtained. The validation of the above methods was carried out by analysing different synthetic mixtures containing HCT and SP. MATLAB 6.5. Software was used for one-dimensional wavelet analysis and the basic concepts about wavelet method were briefly explained. The method developed in this paper is rapid, easy to apply, inexpensive and is suitable for analysing the overlapping signals of compounds in their mixtures without any chemical pre-treatment.
Citation - WoS: 4
Citation - Scopus: 4
Discrete and Continuous Wavelet Transforms for the Multicomponent Determination of Sunset Yellow and Tartrazine in Their Soft Drink Powders
(Chiminform Data S A, 2006) Dinç, E; Baleanu, Dumitru; Baleanu, D; Üstündag, Ö; Aboul-Enein, HY; Matematik
The multicomponent quantitative resolution of the binary mixtures containing, sunset Yellow (SN) and tartrazine (TR) without any pre-chemical treatment, in the presence of the overlapping signals was accomplished by the simultaneous use of the discrete and the continuous wavelet transform (CWT) followed by a zero crossing technique. We propose G transformation approach of signals in wavelet domain, based on both one-dimensional CWT and zero-crossing technique for obtaining a higher resolution of the binary mixtures. The application of this approach contains three steps: firstly, UV-recorded spectra were transferred into the wavelet domain and were subject to the one-dimensional discrete wavelet transform for obtaining an appropriated de-noising signal; secondly, CWT was applied on the de-noising signal and a new transformed signal was obtained so that it contains many zero-crossing points and higher peaks.; thirdly, a zero-crossing technique was applied to the transformed signal obtained in step two, The calibration graphs were drawn by choosing a one-dimensional continuous family, namely, Symlets2 (SYM2) and Gauss3 (GAUS3) followed by a zero-crossing technique. The quantitative analysis of the commercial product containing the above colorants was carried out by using this approach and successful results were obtained.
Citation - WoS: 49
Citation - Scopus: 51
Multidetermination of Thiamine Hcl and Pyridoxine Hcl in Their Mixture Using Continuous Daubechies and Biorthogonal Wavelet Analysis
(Elsevier Science Bv, 2003) Baleanu, D; Dinç, E
A new graphical method based on the one-dimensional wavelet transform (WT) was proposed and tested on mixture of thiamine hydrochloride (THI) and pyridoxine hydrochloride (PYR) in the presence of strongly overlapping signals. We selected from the data of the UV-VIS absorption spectra a signal consisting of 1150 points corresponding to the concentration range 8-32 mg ml(-1) for each vitamin and we subjected it to Daubechies8 (DAUB8) and Biorthogonal6.8 (BIOR6.8) wavelet transforms. Since the peaks of the transformed signals were bigger than original ones a zero crossing method was applied to obtain the calibration graphs. In addition, the validity of Beer-Lambert law was assumed for the transformed signals. An appropriate scale setting was choosing to obtain an alternative calibration for each method. MATLAB 6.5 software was used for one-dimensional wavelet analysis and the basic concepts about wavelet method were given. The obtained results were successfully compared among each other as well as with those obtained by other literature methods. The method developed in this paper is rapid, easy to apply, not expensive and it is suitable for analyzing of the overlapping signals of compounds in their mixtures without any chemical pre-treatment. (C) 2002 Elsevier Science B.V. All rights reserved.
Citation - WoS: 19
Citation - Scopus: 18
A New Application of Chemometric Techniques To Hplc Data for the Simultaneous Analysis of a Two-Component Mixture
(Taylor & Francis inc, 2005) Üstündag, Ö; Özdemir, A; Baleanu, D; Dinç, E
A new chemometric approach using high performance liquid chromatography (HPLC) with photodiode array (PDA) detection was developed and applied to the simultaneous determination of enalapril maleate (EA) and hydrochlorothiazide (HCT) in tablets. Chernometric calibration techniques, classical least squares (CLS), principle component regression (PCR), and partial least squares (PLS) were subjected to the peak area at multiwavelength PDA detector responses. The combination of HPLC and chernometric calibration techniques was called HPLC-CLS, HPLC-PCR, and HPLC-PLS. For comparison purposes, the HPLC method called classical HPLC method was used for the confirmation of the results obtained from combined HPLC-chemometric calibration techniques. A good chromatographic separation between two drugs and internal standard (IS) was achieved using a Waters Symmetry (R) C 18 Column 5 mu m 4.6 x 250 mm and a mobile phase consisting of 0.2M acetate buffer and acetonitrile (v/v, 60:40). The multiwavelength PDA detection was done at 230 (A), 240 (B), 250 (C), 250 (D), 240 (E) nm wavelengths, and peak area was recorded for the concentration set in the mobile phase. Three HPLC-chemometric calibrations and a classical-HPLC method were tested by analyzing the synthetic mixture of EA and HCT in the presence of losartan potassium (IS). The proposed methods were applied to real samples containing the present two drugs. The obtained results were statistically compared with each other.
Citation - WoS: 43
Citation - Scopus: 44
A New Fractional Wavelet Approach for the Simultaneous Determination of Ampicillin Sodium and Sulbactam Sodium in a Binary Mixture
(Pergamon-elsevier Science Ltd, 2006) Baleanu, DB; Dinç, E
A new application of the fractional wavelet transform (FWT) was proposed for the simultaneous determination of ampicillin (AP) and sulbactam (SB) in a pharmaceutical combination for injection. FWT approach is a new powerful tool for removing noise and irrelevant information from the absorption spectra. Cardinal information having higher peak amplitude, eliminated noise, sharp peaks with shrinking width of spectral range was obtained by the application of FWT procedure to the original absorption spectra. In this paper, FWT approach was subjected to the data vector of the UV-signals obtained from AP and SB in the wavelength range of 211.5-313.8 nm. Derivative transform was applied to the original absorption signal together with its FWT generalization. The calibration graphs for AP and SB were obtained by measuring the FWT and usual derivative amplitudes at zero-crossing points. The method validation was carried out by using the synthetic mixture analysis. Our proposed FWT approach was compared with the usual derivative spectrophotometry and chemometric methods (CLS, PCR and PLS) and a good agreement was reported. (c) 2005 Elsevier B.V. All rights reserved.
Citation - WoS: 4
Citation - Scopus: 5
One-Dimension Continuous Wavelet Resolution for the Simultaneous Analysis of Binary Mixture of Benazepril and Hydrochlorothiazide in Tablets Using Spectrophotometric Absorbance Data
(Editura Academiei Romane, 2004) Dinç, E; Baleanu, Dumitru; Baleanu, D; Matematik
One-dimensional continuous wavelets transform (CWT) followed by a zero-crossing technique were applied to the quantitative resolution of a binary mixture of benazepril (BE) and hydrochlorothiazide (HCT) in two commercial tablet formulations. UV-spectra in the range of 210.1-300.0 nm, were recorded and transferred as vectors having 900 components into MATLAB 6.5. The analyzed signals corresponding to the above vectors were subjected to three CWT families, namely, Mexican (MEX), Haar (HA) and Daubechies3 (DAUB3) wavelets. For these three families a detailed analysis procedure was performed and we retained only those parameters creating many zero-crossing points for transformed signals. At locations where the wavelet transform of one component vanishes, the value of the mixture's transformed signal is due only to the other component. This allows rapid approximate determination of the concentrations. The above three wavelet bases provided reliable results of the analysis of the mixtures containing BE and HCT in two pharmaceutical tablet formulations.
Citation - WoS: 20
Citation - Scopus: 22
Simultaneous Spectrophotometric Analysis of Codeine Phosphate, Acetylsalicylic Acid, and Caffeine in Tablets by Inverse Least-Squares and Principal Component Regression Techniques
(Taylor & Francis inc, 2002) Baleanu, D; Onur, F; Dinç, E
Inverse least-squares (ILS) and principal component regression (PCR) techniques were proposed for the spectrophotometric simultaneous analysis of ternary mixture containing codeine phosphate, acetylsalicylic acid and caffeine without any pretreatment. A training set of the title drugs was randomly prepared for both techniques. The absorbance values were measured at the 15 points in the wavelength range 220-290 nm for the absorption spectra. The ILS and PCR calibrations were constructed by using their algorithms and they were tested for the synthetic mixtures of three drugs. Means recoveries and relative standard deviations for ILS and PCR were found as 100.2 and 1.23%, 99.5 and 2.10% for codeine phosphate, 100.5 and 1.30%, 100.3 and 1.18% for acetylsalicylic acid and 99.4 and 1.33%, 99.3 and 1.31% for caffeine, respectively. We realised the numerical computations by using the 'Maple V' software. The results were successfully observed by applying the chemometric techniques to the tablets, and a good agreement was found between the obtained values and the indicated quantities of the pharmaceutical formulation marketed in Turkey.
Citation - WoS: 57
Citation - Scopus: 67
Spectrophotometric Multicomponent Analysis of a Mixture of Metamizol, Acetaminophen and Caffeine in Pharmaceutical Formulations by Two Chemometric Techniques
(Pergamon-elsevier Science Ltd, 2001) Baleanu, D; Onur, F; Dinç, E
Inverse least squares (ILS) and factor-based (principal component analysis (PCA)) techniques were proposed for the spectrophotometric multicomponent analysis of a ternary mixture consisting of metamizol, acetaminophen and caffeine, without prior separation. In these chemometric techniques, the measurements of the absorbance values were realized in the spectral range from 225 to 285 nm in the intervals of Delta lambda = 5 nm at the 13 wavelengths in the zero-order spectra of the different ternary mixtures of these active ingredients in 0.1 M HCl. The prepared calibrations of both techniques using the absorbance data and concentration matrix data sets were used to predict the concentration of the unknown concentrations of metamizol acetaminophen and caffeine in their ternary mixture. The 'MAPLE V' software was used for the numerical calculations, Mean recoveries and relative standard deviations for ILS and PCA techniques were found to be 99.8 and 1.68%, 99.9 and 1,66% for caffeine, 99.8 and 1.84%, 100.4 and 2.85% for metamizol, and 99.7 and 1.04%, 99.6 and 1.34/ for acetaminophen, respectively, for the first and second techniques. The techniques were successfully applied to two pharmaceutical formulations marketed in Turkey and results were compared with a new high-performance liquid chromatography method. (C) 2001 Elsevier Science B.V. All rights reserved.
Citation - WoS: 6
Citation - Scopus: 7
Spectrophotometric Multicomponent Determination of Tetramethrin, Propoxur and Piperonyl Butoxide in Insecticide Formulation by Principal Component Regression and Partial Least Squares Techniques With Continuous Wavelet Transform
(Spectroscopy Soc Canada, Ottawa, 2004) Dinç, E; Baleanu, Dumitru; Baleanu, D; Kanbur, M; Matematik
A continuous wavelet transform (CWT) followed by a principal component regression(PCR) and partial least squares (PLS) were applied for the quantitative determination of tetramethrin (TRM), propoxur (PPS) and piperonil butoxide (PPR) in their formulations. Absorbances of the concentration set formed by TRM, PPS and PPR mixtures were measured at 850 points between 220-350 nm with 0.1 nm intervals, and their absorbance values as absorbance data vectors were transferred into the wavelets domain. A CWT was applied to the absorbance data. The resulting CWT-coefficients (x-block) and concentration set (y-block) were used for the construction of CWT-PCR and CWT-PLS calibrations. The combination of both continuous wavelet and chemometrics techniques indicates good results for the determination of insecticide in synthetic mixtures and commercial formulation.
Citation - WoS: 59
Citation - Scopus: 68
Spectrophotometric Quantitative Determination of Cilazapril and Hydrochlorothiazide in Tablets by Chemometric Methods
(Pergamon-elsevier Science Ltd, 2002) Baleanu, D; Dinç, E
Four chemometric methods were applied to simultaneous determination of cilazapril and hydrochlorothiazide in tablets. Classical least-square (CLS), inverse least-square (ILS), principal component regression (PCR) and partial least-squares (PLS) methods do not need any priori graphical treatment of the overlapping spectra of two drugs in a mixture. For all chemometric calibrations a concentration set of the random mixture consisting of the two drugs in 0.1 M HCl and methanol (1:1) was prepared. The absorbance data in the UV-Vis spectra were measured for the 15 wavelength points (from 222 to 276 nm) in the spectral region 210-290 nm considering the intervals of Deltalambda = 4 nm. The calibration of the investigated methods involves only absorbance and concentration data matrices. The developed calibrations were tested for the synthetic mixtures consisting of two drugs and using the Maple V software the chemometric, calculations were performed. The results of the methods were compared each other as well as with HPLC method and a good agreement was found. (C) 2002 Elsevier Science B.V. All rights reserved.
Citation - WoS: 28
Citation - Scopus: 33
Two New Spectrophotometric Approaches To the Multicomponent Analysis of the Acetaminophen and Caffeine in Tablets by Classical Least-Squares and Principal Component Regression Techniques
(Elsevier Science Sa, 2002) Baleanu, D; Dinç, E
Classical least-squares (CLS) and principal. component regression (PCR) techniques were proposed for the simultaneous analysis of tablets containing acetaminophen and caffeine without using a chemical separation procedure. The chemometric calibrations were prepared by measuring the absorbances values at the 15 wavelengths in the spectral region 215-285 nm and by using a training set of the mixtures of both drugs in 0.1 M HCl. The obtained chemometric calibrations were used for the estimation of acetaminophen and caffeine in samples. The numerical calculations were performed with the 'MAPLE V' software. By applying two techniques to synthetic mixtures, the mean recoveries and the relative standard deviations in the CLS and PCR techniques were found as 99.5 and 1.29, 99.7 and 1.00% for acetaminophen and 99.9 and 1.92, 100.0 and 1.178% for caffeine, respectively. Our results were compared with those obtained previously by one of us considering HPLC method as a reference method. These two methods were successfully applied to a pharmaceutical tablet formulation of two drugs. (C) 2002 Elsevier Science S.A. All rights reserved.