Abdürrezzak Bozdoğan

Simultaneous determination of potassium guaiacolsulfonate, guaifenesin, diphenhydramine HCl and carbetapentane citrate in syrups by using HPLC-DAD coupled with partial least squares multivariate calibration

A simple and rapid analytical procedure was proposed for the determination of chromatographic peaks by means of partial least squares multivariate calibration (PLS) of high-performance liquid chromatography with diode array detection (HPLC-DAD). The method is exemplified with analysis of quaternary mixtures of potassium guaiacolsulfonate (PG), guaifenesin (GU), diphenhydramine HCI (DP) and carbetapentane citrate (CP) in syrup preparations. In this method, the area does not need to be directly measured and predictions are more accurate. Though the chromatographic and spectral peaks of the analytes were heavily overlapped and interferents coeluted with the compounds studied, good recoveries of analytes could be obtained with HPLC-DAD coupled with PLS calibration. This method was tested by analyzing the synthetic mixture of PG, GU, DP and CP. As a comparison method, a classsical HPLC method was used. The proposed methods were applied to syrups samples containing four drugs and the obtained results were statistically compared with each other. Finally, the main advantage of HPLC-PLS method over the classical HPLC method tried to emphasized as the using of simple mobile phase, shorter analysis time and no use of internal standard and gradient elution.

Simultaneous Determination of Mepyramine Maleate, Lidocaine Hydrochloride, and Dexpanthenol in Pharmaceutical Preparations by Partial Least‐Squares Multivariate Calibration

Abstract A partial least‐squares calibration (PLS) method has been developed for simultaneous quantitative determination of mepyramine maleate (MAM), lidocaine hydrochloride (LIH), and dexpanthenol (DPA) in pharmaceutical preparations. The resolution of these mixtures has been accomplished by using partial least‐squares (PLS‐2) regression analysis of electronic absorption spectral data without prior separation or derivatization. The experimental calibration matrix was constructed with 27 samples. The concentration ranges considered were 2, 3, 4 µg mL−1 for MAM, 2, 3, 4 µg mL−1 for LIH, and 8, 10, 12 µg mL−1 for DPA. The absorbances were recorded between 190 and 340 nm every 5 nm. The results show that PLS‐2 is a simple, rapid, and accurate method applied to the determination of these compounds in pharmaceuticals.

Spectrophotometric multicomponent analysis of a mixture of chlorhexidine hydrochloride and lidocaine hydrochloride in pharmaceutical formulation using derivative spectrophotometry and partial least-squares multivariate calibration

Two spectrophotometric methods were applied to the simultaneous assay of chlorhexidine hydrochloride (CHL) and lidocaine hydrochloride (LIH) in pharmaceutical formulations. Using derivative spectrophotometry, CHL was determined by measurement of its first derivative signal at 290 nm (peak to zero amplitude) in the concentration range 5–9 μg/mL, and LIH was analysed by measurement of its second derivative signals at 272 and 276 nm (peak to peak amplitude) in the concentration range 160–480 μg/mL. With the partial least-squares (PLS-2), the experimental calibration matrix was constructed using 9 samples. The concentration ranges considered were 5–7 μg/mL for CHL and 220, 240, 260 μg/mL for LIH. The absorbances were recorded between 240 and 310 nm at every 5 nm.

Simultaneous determination of Sunset Yellow and Ponceau 4R in gelatin powder by derivative spectrophotometry and partial least-squares multivariate spectrophotometric calibration.

ABSTRACT Two methods for the simultaneous determination of Sunset Yellow and Ponceau 4R in gelatin powders by first derivative spectrophotometry and by partial least-squares multivariate spectrophotometric calibration are described. These procedures do not require any separation step. These methods were applied to determine both colorants in commercial gelatin powders and the results obtained were compared. A good statistical agreement was obtained between the results.

Water-soluble TRIS-terminated PAMAM dendrimers: microwave-assisted synthesis, characterization and Cu(II) intradendrimer complexes

This study is the first report describing the microwave-assisted synthesis (MAS) of poly(amido amine) (PAMAM) dendrimers with TRIS surface functional groups (PAMAM–TRIS). Six PAMAM–TRIS dendrimers were synthesized using both newly developed conventional and microwave methods. Five of them are novel. Three different cores, one polymeric Jeffamine® T-403 and two monomeric, ethylenediamine and diethylenetriamine, were used in the syntheses. All the reactions were monitored by attenuated total reflectance (ATR). It was observed that microwave reactions proceeded 3.5 to 4.0 times faster than conventional reactions. Therefore, a fast, easy and one-pot MAS of six different water-soluble PAMAM–TRIS dendrimers was accomplished with high (90–96%) yields in short (110–140 min) reaction times and under mild reaction conditions, using methanol as solvent. The other ester terminated half generation precursor PAMAM (PAMAM–OCH3) dendrimers used for the synthesis of the PAMAM–TRIS dendrimers were obtained by utilizing conventional and microwave methods together. For the purification of all the PAMAM dendrimers, a liquid phase polymer-based retention (LPR) technique was used. The PAMAM–TRIS dendrimers were characterized by 1H NMR, 13C NMR, ATR (IR), EA, potentiometric and spectroscopic titrations. Furthermore, Cu(II)–PAMAM–TRIS dendrimer complexes were prepared and characterized by UV-Vis spectroscopy. The synthesized PAMAM–TRIS dendrimers can be considered as new drug carrier systems and should find use in widespread application fields, especially in future pharmaceutical and catalytic studies but also in other fields.

Simultaneous Determination of Theobromine and Caffeine in Cocoa by Partial Least-Squares Multivariate Spectrophotometric Calibration

The use of partial least - squares multivariate spectrophotometric calibration for the simultaneous determination of theobromine and caffeine in cocoa is presented. The results show that these components in a molar ratio of about 6 : 1 in cocoa have been determined simultaneously with standard deviations of about 0.05 and 0.02 for theobromine and caffeine, respectively.

Abilities of Partial Least‐Squares (PLS‐2) Multivariate Calibration in the Analysis of Quaternary Mixture of Food Colors (E‐110, E‐122, E‐124, E‐131)

Abstract Sunset Yellow (SY), Carmoisine (C), Ponceau 4R (P), and Patent Blue V (PB) are synthetic organic dyes which are under governmental regulations all over the world because of their toxicity and carcinogenicity. In this study, a simple and fast analytical procedure was proposed for the simultaneous determination of food dyes (SY, C, P, and PB) in powder drinks by means the partial least‐square treatment of spectrophotometric absorbance between 450 –730 nm, taken at 10 nm intervals. The experimental calibration matrix was constructed with 27 samples. The concentration ranges considered were 2, 3, 4 µg · ml−1 for SY, 7, 8, 9 µg · ml−1 for C, 9, 10, 11 µg · ml−1 for P, and 0.3, 0.4, 0.5 µg · ml−1 for PB. The method was applied to the determination of dyes in different commercially available powder drinks. The results obtained by the application of the PLS‐2 method were statistically compared with those obtained by an HPLC method using the F and t tests. Very similar values were found by two methods. No time consuming pretreatment was needed and this method also provides rapid, accurate and economical analysis of these colors.

INVESTIGATIONS OF THE INTERACTION OF 4′,5′-BIS(SALICYLIDENEIMINO) BENZO-15-CROWN-5 WITH TRANSITION AND ALKALI METAL IONS AND THE URANYL CATION

Abstract Formation constants for complexes of Co(II), Cu(II), Ni(II) and U(VI)O2 and 4,′5-bis(salicylideneimino)benzo-15-crown-5 (H2L) have been measured at 25 ± 0.1 °C and I = 1 M (KCl) by potentiometric techniques. Protonation constants of the ligand and overall formation constants have been calculated from potentiometric data using the program TITFIT. Both imino nitrogen and phenol groups provide donor atoms together with hydroxyl ions at higher pH values. The alkali ion binding capability of the crown ether groups of CuL and NiL measured by alkali extraction experiments gives the order K+ > Na+ > Li+.

Experimental design of reversed-phase high performance liquid chromatographic conditions for simultaneous determination of ibuprofen, pseudoephedrine hydrochloride, chlorpheniramine maleate, and nipagen

Abstract25-1 fractional factorial design was applied to optimize the chromatographic conditions of the RP-HPLC determination of ibuprofen, pseudoephedrine hydrochloride, chlorpheniramine maleate, and nipagen in syrup preparation. All the factors that affect the determination of components and their interactions were investigated. pH, flow rate and solvent ratios for three steps of gradient profile were regarded as factors to be investigated in two levels. The resolution was chosen as analytical response. The limit of quantitations (10 s/m) were found as 0.9, 1.0, 0.4, and 0.12 μg/mL for ibuprofen, pseudoephedrine hydrochloride, chlorpheniramine maleate, and nipagen, respectively.

CHROMATOGRAPHIC AND CHEMOMETRICS-ASSISTED SPECTROPHOTOMETRIC METHODS FOR THE SIMULTANEOUS DETERMINATION OF ALLOBARBITAL, ADIPHENINE HYDROCHLORIDE, AND PARACETAMOL IN SUPPOSITORY

High-performance liquid chromatography (HPLC) and multivariate spectrophotometric methods were developed for the simultaneous determination of allobarbital (ALO), adiphenine hydrochloride (ADI), and paracetamol (PAR) in suppository medication. The HPLC method was performed on a C18 column with a mobile phase consisting of a mixture of acetonitrile and buffer solution (pH 4.0) of sodium acetate and acetic acid (60:40, v/v) and UV detection at 195 nm. This method was validated for its linearity, precision, accuracy, and robustness. Also, the resolution of three components has been accomplished by using the multivariate calibration methods PCR and PLS-2. Experimental calibration matrix was constructed using 27 samples, according to the 33 full factorial design. These chemometric methods were tested by analyzing the synthetic mixtures of three drugs. The proposed methods were succesfully applied for the analysis of pharmaceutical formulations containing ALO, ADI, and PAR combinations and the obtained results were statistically compared with each other.