Browsing by Author "Dinç, Erdal"

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Chemometric Methods for the Simultaneous Spectrophotometric Determination of Telmisartan and Hydrochlorotiazide in the Commercial Pharmaceuticals
(Chiminform Data S A, 2009) Beliz, Kaya; Dinç, Erdal; Baleanu, Dumitru; 6981; Matematik
Simultaneous spectrophotometric determination of telmisartan (TEL) and hydrochlorothiazide (HCT) in two different commercial pharmaceutical preparations were performed by using three different chemometric methods, namely principal component regression (PCR), partial least squares (PLS) and artificial neural network (ANN). The proposed chemometric methods do not require chemical seperation and spectral graphical procedures for the quantitative resolution of mixtures containing the titled compounds. In the preparation of chemometric calibrations, a concentration set of 45 synthetic mixtures containing TEL and HCT in the linear concentration range of 1.0-26.0 and 1.0-17.0 mu g/mL, respectively was simetrically prepared in methanol. The spectra of the above concentration set and samples were recorded in the spectral range of 200-350 nm. Concentration set and its corresponding absorbances in the selected spectral range corresponding to the 250-350 nm wavelength range was used to obtain PCR, PLS and ANN calibrations. Recovery study, intra-day, inter-day and standard addition technique were considered as method validation. Three proposed chemometric approaches were sucessfully applied to the quantitative analysis of two different commercial pharmaceutical products
Continuous wavelet analysis for the ratio signals of the absorption spectra of binary mixtures
(Springer, 2007) Dinç, Erdal; Baleanu, Dumitru; Taş, Kenan; 56389; Matematik
Wavelet analysis is successfully applied to the quantitative determination of the components in the binary mixture. This mathematical application is based on the use of the division of the absorption signals by the standard absorption signal and the transformation of the ratio signals. Calibration functions are obtained by measuring the continuous wavelet amplitudes corresponding to the minimum points of the wavelengths. The method is validated and applied to one example of binary mixture analysis.
Multidetermination of thiamine HCl and pyridoxine HCl in their mixture using continuous daubechies and biorthogonal wavelet analysis
(Elsevier Science BV, 2003) Dinç, Erdal; Baleanu, Dumitru; 56389; Matematik
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.
-Simultaneous chemometric determination of pyridoxine hydrochloride and isoniazid in tablets bymultivariate regression methods
(2010) Dinç, Erdal; Üstündağ, Ögür; Baleanu, Dumitru; 56389; Matematik
The sole use of pyridoxine hydrochloride during treatment of tuberculosis gives rise to pyridoxine deficiency. Therefore, a combination of pyridoxine hydrochloride and isoniazid is used in pharmaceutical dosage form in tuberculosis treatment to reduce this side effect. In this study, two chemometric methods, partial least squares (PLS) and principal component regression (PCR), were applied to the simultaneous determination of pyridoxine (PYR) and isoniazid (ISO) in their tablets. A concentration training set comprising binary mixtures of PYR and ISO consisting of 20 different combinations were randomly prepared in 0.1 M HCl. Both multivariate calibration models were constructed using the relationships between the concentration data set (concentration data matrix) and absorbance data matrix in the spectral region 200-330 nm. The accuracy and the precision of the proposed chemometric methods were validated by analyzing synthetic mixtures containing the investigated drugs. The recovery results obtained by applying PCR and PLS calibrations to the artificial mixtures were found between 100.0 and 100.7%. Satisfactory results obtained by applying the PLS and PCR methods to both artificial and commercial samples were obtained. The results obtained in this manuscript strongly encourage us to use them for the quality control and the routine analysis of the marketing tablets containing PYR and ISO drugs. Copyright
Spectrophotometry simultaneous determination of levamisole and triclabendazole in tablets by principal component regression and partial least squares chemometric methods
(2008) Pektas, Gözde; Dinç, Erdal; Baleanu, Dumitru; 56389; Matematik
Principal component regression (PCR) and partial least squares (PLS) chemometric methods were applied to the simultaneous quantitative analysis of levamisole (LVM) and triclabendazole (TCB) in tablets without using a preliminary separation, even in presence of the overlapping spectra of the above compounds. For both PCR and PLS, a concentration set containing 25 different mixtures of LVM and TCB in the linear concentration range was symmetrically prepared and then the absorbance values of the concentration set were measured at the wavelength set with Δλ=0.1 nm in the spectral region of 225-322.3 nm. PCR and PLS calibrations were obtained by applying the PCR and PLS algorithms to the concentration set data (y-block) and their corresponding absorbance data (x-block). The validity of PCR and PLS chemometric methods was performed by using the independent synthetic mixtures and the standard addition technique. Then, these analytical methods were applied to the commercial tablets and a good agreement was obtained between experimental results provided by the application of the PCR and PLS to the synthetic and real samples.