Ismail Murat Palabiyik

Simultaneous spectrophotometric determination of ezetimibe and simvastatin in pharmaceutical preparations using chemometric techniques

Two spectrophotometric methods are described for the simultaneous determination of ezetimibe (EZE) and simvastatin (SIM) in pharmaceutical preparations. The obtained data was evaluated by using two different chemometric techniques, Principal Component Regression (PCR) and Partial Least-Squares (PLS-1). In these techniques, the concentration data matrix was prepared by using the mixtures containing these drugs in methanol. The absorbance data matrix corresponding to the concentration data matrix was obtained by the measurements of absorbances in the range of 240 - 300 nm in the intervals with Δλ = 1 nm at 61 wavelengths in their zero order spectra, then, calibration or regression was obtained by using the absorbance data matrix and concentration data matrix for the prediction of the unknown concentrations of EZE and SIM in their mixture. The procedure did not require any separation step. The linear range was found to be 5 - 20 µg mL-1 for EZE and SIM in both methods. The accuracy and precision of the methods were assessed. These methods were successfully applied to a pharmaceutical preparation, tablet; and the results were compared with each other.

Optimization of the experimental conditions for macrolide antibiotics in high performance liquid chromatography by using response surface methodology and determination of tylosin in milk samples

The simple, rapid and sensitive liquid chromatographic separation of five macrolides (tilmicosin, erythromycin, tylosin, roxithromycin and josamycin) widely used in food producing animals was developed. Response surface methodology was used as an optimization method of mobile phase, column temperature and pH to provide the best resolution of these analytes. The separation was performed by using an end-capped X-Terra RP-18 column (250 × 4.6 mm I.D × 5 m) with an isocratic system of 15 mM hydrochloric acid (pH 2.5)-acetonitrile as the mobile phase at a temperature of 30°C and flow-rate of 1.0 mL/min. The suitability of the method for multi-residue determination of the macrolides is demonstrated by the analysis of milk samples spiked with tylosin. Roxithromycin was used as internal standard. The recovery of tylosin was quite good as 90.8%. The limit of quantification and detection limit were 0.024 and 0.007 μg/mL, respectively. The method was successfully applied to determination of macrolides at levels below the maximum concentration legally allowed in milk samples.

Liquid Chromatographic and Spectrophotometric Determination of Phenazopyridine Hydrochloride, Ampicilline Trihydrate, and Nitrofurantoine in Pharmaceutical Preparations

Abstract The present work describes two new liquid chromatographic (LC) methods and three new spectrophotometric methods for the simultaneous determination of phenazopyridine hydrochloride (PHEN), ampicilline trihydrate (AMP), and nitrofurantoine (NIT) in their binary combinations. In the LC methods, a Nucleosil C8 column with a mobile phase composed of methanol–acetonitril–water (42:42:16, v/v/v) with ultraviolet (UV) detection at 260 nm was used for a PHEN–NIT combination and a Nucleosil C8 column with a mobile phase composed of methanol–water (80:20, v/v) with UV detection at 240 nm was used for the PHEN–AMP combination. For spectrophotometric methods, a ratio spectra derivative spectrophotometric and two chemometric methods in spectrophotometry were used. In ratio spectra derivative spectrophotometric methods, analytical signals were measured at the wavelengths corresponding to either maximums and minimums for these drugs in the second derivative spectra of the ratio spectra obtained by using every other zero‐order spectra as the divisor in their solution in methanol–0.1 M HCl (1:1) for PHEN–NIT and PHEN–AMP mixtures in the 200–300 nm range. Principal component regression (PCR) and partial least‐squares (PLS‐1) methods were used as chemometric techniques. In these techniques, the concentration data matrix was prepared by using the synthetic mixtures containing these drugs in methanol–0.1 M HCl (1:1). The absorbance data matrix corresponding to the concentration data matrix was obtained by the measurements of absorbances at more than 14 wavelengths in the range 200–300 nm, at appropriate Δλ in the zero‐order spectra in both techniques for these two binary combinations. The spectrophotometric procedures do not require any separation step. The accuracy, precision, and the linearity ranges of the methods have been determined, and they have been validated by analyzing synthetic mixtures containing the title drugs. These four methods were successfully applied to the pharmaceutical formulations, capsule, and tablet, and the results were compared with each other.

Gold nanoparticle-lignan complexes inhibited MCF-7 cell proliferation in vitro: a novel conjugation for cancer therapy.

Nanoparticles, including gold nanoparticles (AuNP), have been used in imaging in cancer treatment and as therapeutic agents and drug delivery vehicles. Particularly lignans, also called phytoestrogens, have strong effects on the treatment of carcinomas due to their antiestrogenic, antiangiogenic and proapoptotic mechanism. The aim of this study is to investigate the antiproliferative effects of three lignans-AuNP conjugates, pinoresinol (PINO), lariciresinol (LARI) and secoisolariciresinol (SECO), on the MCF-7 cell lines. For this purpose, first, thiolated β-cyclodextrin (β-CD) was synthesized to achieve a surface modification of AuNP, and then the β-CD modified AuNP was characterized using the transmission electron microscopy (TEM), UV-Visible and Nuclear Magnetic Resonance (NMR) spectroscopy. Then, the selected lignans were conjugated to the β-CD-modified AuNP, and the antiproliferative effect of these conjugates was monitored. The results suggest that when compared to their non-conjugated forms, the AuNP-bound lignan conjugates prevented the proliferation of the MCF-7 cells significantly. Therefore, these AuNP-conjugated derivatives can be new candidate agents for breast cancer therapy.

SIMULTANEOUS SPECTROPHOTOMETRIC AND LIQUID CHROMATOGRAPHIC DETERMINATION OF DEXTROMETHORPHAN HYDROBROMIDE, PHENYLEPHRINE HYDROCHLORIDE AND CARBINOXAMINE MALEATE IN PHARMACEUTICAL PREPARATIONS

Simultaneous determination of dextromethorphan hydrobromide (DEX), phenylephrine hydrochloride (PHEN), and carbinoxamine maleate (CAR) in pharmaceutical preparations was performed by using liquid chromatograpy (LC) and spectrophotometry. In LC, the separation was achieved on a C18 column and the optimal mobile phase for satisfactory separation in a gradient elution program was found to be acetonitrile-sodium perchlorate solution (5: 95, v/v) initially, then a linear gradient up to 60% acetonitrile in 8 min. In spectrophotometric method, a chemometric technique, principal component regression (PCR), was used. In the method, the absorbance data matrix corresponding to the concentration data matrix was obtained by the measurement of absorbances in their zero order spectra by Δλ = 1 nm in the 210–300 nm range. Then, the calibration was obtained by using this data matrix for the prediction of unknown concentrations of DEX, PHEN, and CAR in their ternary mixture. The methods proposed were validated and successfully applied to a pharmaceutical preparation, capsule, and the results were compared.

Chemometric methods for simultaneous quantification of lactic, malic and fumaric acids

Lactic, fumaric and malic acids are commonly used in food and pharmaceutical industries. During microbial production of these compounds, it is important to determine their concentrations in the fermentation broth with a rapid and sensitive method. Spectrophotometry is commonly used. However, UV‐spectral overlap between these organic acids makes it difficult to determine each of them individually from the mixture. In order to overcome this problem, statistical methods, namely principal component regression (PCR) and partial least squares‐1 methods, were tested and compared with conventional HPLC techniques. The absorbance data matrix was obtained by measuring the absorbances of 21 ternary mixtures of lactic, fumaric and malic acids in a wavelength range of 210–260 nm. Calibration and validation were performed by using the data obtained in a mixture of these organic acids. The prediction abilities of the methods were tested by applying them to fermentation broths. The precision of the PCR method was better than that of the partial least squares‐1 method. In the PCR method, the correlation coefficients between actual and predicted concentrations of the organic acids were calculated as 0.970 for lactic acid and 0.996 for fumaric acid in fermentation broths. The concentration of malic acid was not detected due to its low concentration in samples. These results show that the PCR method can be applied for simultaneous determination of lactic, fumaric and malic acids in fermentation broths.

STABILITY-INDICATING MICELLAR ELEKTROKINETIC CHROMATOGRAPHY METHOD FOR DETERMINATION OF FINASTERIDE IN PHARMACEUTICAL PREPARATIONS

A stability-indicating micellar electrokinetic chromatography method has been developed and validated for determination of finasteride. Analysis was performed by using 50 cm × 100 µm i.d. (effective length 42.8 cm) fused silica capillary and background electrolyte of 50 mM NaH2PO4 (pH 3) buffer containing 10 mM sodium dodecyl sulfate as surfactant. Applied potential was selected as −15 kV at 25°C and the detection was at 210 nm. The calibration curve was linear in the range of 5–50 µg · mL−1. Effects of pH, capillary temperature, applied voltage, and buffer concentration were investigated. Degradation studies were carried out under acidic (1.0 M HCl), basic (1.0 M NaOH), oxidative (%10 H2O2), thermal (60°C), and UV-light (254 nm) conditions and it was found that finasteride was degraded under acidic, basic, and oxidative stress conditions. The method was successfully applied to the determination of finasteride in tablet formulations.

Optimisation and validation of liquid chromatographic and partial least-squares-1 methods for simultaneous determination of enalapril maleate and nitrendipine in pharmaceutical preparations

Simultaneous determination of enalapril maleate (ENA) and nitrendipine (NIT) in pharmaceutical preparations was performed using liquid chromatography (LC) and the partial least-squares-1 (PLS-1) method. In LC, the separation was achieved on a C8 column and the optimum mobile phase for good separation in a gradient elution programme was found to be acetonitrile-water (φr = 81: 19) and optimum flow-rate, temperature, injection volume, and detection wavelength were set at 1.0 mL min−1, 25°C, 10 μL, and 210 nm, respectively. Dienogest was selected as an internal standard. In the spectrophotometry, a PLS-1 chemometric method was used. The absorbance data matrix related to the concentration data matrix was established by measurement of absorbances in their zero order spectra with an increment of Δλ = 1 nm in the 220–290 nm range for ENA and with Δλ = 1 nm in the 230–290 nm range for NIT in the PLS-1 method. Following this step, calibration was established by using this data matrix to predict the unknown concentrations of ENA and NIT in their binary mixture. These optimised methods were validated and successfully applied to a pharmaceutical preparation in tablet form and the results were subjected to comparison.

Using derivative and ratio spectra derivative: spectrophotometries as new data preprocessing method in partial least squares technique for resolving overlapped spectra of montelukast sodium, desloratadine, and levocetirizine dihydrochloride

Abstract Chemometric techniques are widely used for resolving overlapped spectra in different analysis type including simultaneous determination of active ingredients in pharmaceutical preparation. Processed data are used in some instances alternative to the raw data. Standardization, normalization, and mean centering are preferred data preprocessing methods in multivariate analysis techniques. In this study, derivative and ratio spectra derivative spectrophotometric methods are used in preprocessing for spectrophotometric data as an alternative to the other procedure in partial least squares technique (PLS-1) for resolving overlapped spectra of ternary mixtures of montelukast sodium, desloratadine, and levocetirizine dihydrochloride. Simultaneous determination and quantitation of these active ingredients from their bulk solutions and pharmaceutical preparations was achieved successfully by this developed and optimized partial least squares method. These results indicate that derivative and ratio spectra derivative spectrophotometric methods will be used as a new data preprocessing method in chemometric techniques from now on.

Usage of multivariate optimization techniques in drug analysis using spectrophotometric methods

T newly developed Net Analyte Signal Standard Addition Method (NASSAM) for the simultaneous estimation of berberine and curcumine was simple, specific, accurate, precise, rapid, sensitive and economical which indicate its adequacy for routine pharmaceutical analysis. NASSAM is used for the spectrophotometric determination of analyte in the multicomponent system. Spectrophotometric measurements were made on Perkin Elmer Lambda 35 UV/visible spectrophotometer coupled with computer loaded with UV Win Lab PC software version 6.0.3. All spectra were scanned at 210-520 nm and saved in CSV format and then data were statistically analysed by unscrambler® 10.2. The LOD and LOQ were found to be 0.063 μg/mL and 0.207 μg/mL for berberine and 0.019 μg/mL and 0.065 μg/mL for curcumin, respectively. The percentage purity of the market formulation Talekt for berberine and curcumin were found to be 94.13% w/w and 96.98% w/w, respectively. This method was simple, precise, accurate, sensitive and reproducible and can be used for the routine quality control testing for the marketed polyherbal formulations. Nitin Sharma et al., J Anal Bioanal Tech 2013, 4:5 http://dx.doi.org/10.4172/2155-9872.S1.015N mixed-mode monolithic stationary phases for chromatographic separation (CEC and μ-LC) employing solubilization by complexation with β-cyclodextrin were synthesized. Free radical copolymerization was performed in aqueous solution with a cyclodextrin-solubilized hydrophobic monomer, a water-soluble crosslinker (piperazinediacrylamide), and a charged monomer (vinylsulfonic acid). Different hydrophobic methacrylate monomers (isobornyl, adamantyl, cyclohexyl, and phenyl methacrylate) were investigated. Chromatographic properties of the synthesized monoliths were studied with aqueous and nonaqueous mobile phases with hydrophobic and hydrophilic analytes. Due to the amphiphilic nature of the polymers synthesized, the elution orders obtained correspond to the RP mode and to the normal-phase mode dependent on the polarity of the mobile phase. However, observations made with polar solutes and polar mobile phase can only be explained by a mixed-mode retention mechanism. The influence of the total monomer concentration (%T) on the chromatographic properties and on the specific permeability was elucidated. Run-to-run, day-to-day, and capillary-to-capillary reproducibility of electroosmotic mobility and retention factors were determined. Comparison of retention data with those of a commercial octadecyl silica gel HPLC column reveals that the methylene selectivity of the monolithic capillaries prepared in this study is very similar to that of routinely used octadecyl silica gels. Fuad Al-Rimawi, J Anal Bioanal Tech 2013, 4:5 http://dx.doi.org/10.4172/2155-9872.S1.015A conference paper by Dr. Naumih M. Noah a lecturer at United States International University - Africa, at 4th International Conference and Exhibition on Analytical & Bioanalytical Techniques.W describe the design and development of several microfluidic-based assays to study the bone turnover marker (BTM) osteocalcin (BGLAP) and the antibiotic teicoplanin from Actinoplanes teichomyceticus. Fluorescence and surface plasmon resonance (SPR) based assays were developed. In the first, fluorescence was measured upon binding the fluorescently labeled monoclonal-anti BGLAP-clone 2D5 antibody to BGLAP electrostatically attached to a microfluidic channel modified with 3-aminopropyltriethoxysilane (APTES). In the second, an open-sandwich enzyme-linked immunoadsorbent assay (ELISA) for BGLAP on a microfluidic chip was developed. In the third, BGLAP, bound to a self-assembled monolayer (SAM), was used to show binding to an unlabeled antibody using SPR. In the fourth, a magnetic bead-based technique was used to assess the binding of magnetic microspheres covalently attached to BGLAP with the fluorescently labeled antibody. A dissociation constant (Kd=330 nM) for the BGLAP-antibody interaction is reported. A genetically tuned neural network platform to optimize the fluorescence realized upon binding 5-carboxyfluorescein-D-Ala-D-Ala-D-Ala (5-FAM-(D-Ala)3) (1) to teicoplanin electrostatically attached to a microfluidic channel originally modified with 3-aminopropyltriethoxysilane (APTES) is described. Here, three parameters are examined at a constant concentration of 1, with neural network methodology applied to optimize fluorescence. Optimal neural structure provided a best fit model, both for the training set (r2=0.985) and testing set (r2=0.967) data. Simulated results were experimentally validated demonstrating efficiency of the neural network approach. These results demonstrate the potential of developing versatile microfluidic-based platforms with various detection schemes for the study of multiple molecular systems. Frank A. Gomez et al., J Anal Bioanal Tech 2013, 4:5 http://dx.doi.org/10.4172/2155-9872.S1.015A novel zirconia nanoparticles based electrochemical sensor has been developed via drop casting method and the electrochemical sensor was characterized with scanning electron microscopy (SEM). The electrochemical behaviour of ethionamide (ETA) at zirconia modified glassy carbon electrodes (GCEs) were investigated by cyclic voltammetry (CV) and square-wave voltammetry (SWV) and results indicated that the electrode process is diffusion controlled. The decrease of charge transfer resistance was also analysed by electrochemical impedance spectroscopy. Under the optimal conditions, the peak current of SWV increased linearly with the ETA concentration in the range from 150 650 ng/mL with a limit of detection (LOD) 47.66 ng/mL and its application for the electrochemical detection of ethionamide (ETA) in solubilized system has also been reported.D developing an analytical method, investigating the effects of several experimental variables on the response from analytical devices is important in terms of optimizing a developed method. One-factor-at-a-time approach is a traditional optimization technique for describing optimal experimental conditions. Owing to some disadvantages of this technique such as high consumption amount of solvent and sample, waste of time, dissipation of energy and high cost, in recent years, multivariate approaches has been used for accomplishing these problems. In multivariate optimization techniques, several variables effects on response are evaluated simultaneously and results are determined as contour graphics and equations. Helping with these equations containing coefficients, the value of the one factor was calculated for providing the optimum experimental conditions when the other factors were valued while the graphics are enabled to monitoring the effects of experimental variables on responses visually. Determination of active ingredients in pharmaceutical preparations becomes more difficult when the number of the active components increase in the mixture and the presence of interference from excipients in the preparations. In addition to the chromatographic techniques, chemometric techniques (multivariate calibration techniques), based on the computer aided instrumentation and algorithms, are used for resolving mixtures and employed for the analysis of multi-component samples. Multivariate optimization techniques reduce the time for optimization studies via investigating the influence of factors on response in chemometric techniques, simultaneously and contributed the utility of this analytical technique. Ismail Murat Palabiyik, J Anal Bioanal Tech 2013, 4:5 http://dx.doi.org/10.4172/2155-9872.S1.015S is the process of analyzing a medicinal herb so that one or more of its key constituents is present in a predefined “standard” amount. The data behind standardization is to ensure that each dose recommended contains consistent amount of the key active ingredients that give desired therapeutic or nutritional effect. From a CRO or third party laboratory point of view, this demand could be for product registration/regulatory purposes and/or to satisfy the customer needs about product quality and efficacy. The paper discusses some of the analytical quality assurance methods developed for some plant-based dietary supplements/Ayurvedic Indian medicines to gain entry into US and European markets and to meet required regulatory requirements. G. Sudesh Kumar, J Anal Bioanal Tech 2013, 4:5 http://dx.doi.org/10.4172/2155-9872.S1.015A simple, precise, rapid, selective, and economic high-performance thin layer chromatography (HPTLC) method has been established for estimation analysis of BAL. HPTLC method was developed using Chloroform: methanol (3.5:2, v/v) as a Mobile Phase and Pre-coated silica gel G60–F254 aluminum sheet as a SP. Detection wavelength was 361 nm. In HPTLC linear range was 500-3000 ng/band, mean recoveries were found to be 99.99-100.04% & Rf of a BAL was found to be 0.61. This HPTLC method is economic, sensitive, and less time consuming than other chromatographic procedures. It is a user-friendly and importance tool for analysis of tablet dosage forms.H drugs and their derivatives, as well as herbal medicinal products represent a challenge in the analytical field, not only due to the complexity of their composition in active substances, at different concentration levels, but also from the point of view of stability of such active ingredients. The biological effect of an herbal medicine is resulted by the complex of constituents more than by the major and isolated active ingredients, thus their technological processing must preserve as much as possible its overall composition. Therefore an appropriated analytical method must be selective and allow monitoring the overall composition of raw materials, intermediate products and the final formulations of herbal medicines. After the processing of the extractive solutions by techniques involving heat, for instance by spray drying, commonly used to produce dried extract, it is common to observe the loss of a particular biological activity and the maintenance of other biological activities. A detailed inspection on chromatographical profile of the samples, before and after the heat treatment, may reveal what substances may play a role in the biological effect studied, though sometimes it will be necessary to couple techniques to reveal the differences in the sample composition. However, to understand which substances play a role in the biological effect, a previous submission to stress tests to simulate or predict the sample behavior is useful. Monitoring its concentration level and its liability simulating stress conditions to which the samples will be submitted is very important in the development of analytical methods. The stress conditions must be well planned to closely simulate the technological processes employed in producing intermediate and finished products and also in the physiology conditions of administrations (as example the gastrointestinal pH). In addition, the lyotropic studies parameters (as example, dissolution medium, apparatus, rotation) must be established to develop a discriminative dissolution method for oral dosage forms based on phytomedicine. In this way, which are the substances that should be bioavailable and measured to construct the dissolution profile? To understand what substances are involved in the aimed biological activity it is essential to correlate it to the number and level of constituents in the original and stressed samples. Tania Mari Belle Bresolin, J Anal Bioanal Tech 2013, 4:5 http://dx.doi.org/10.4172/2155-9872.S1.015