Novel RP-HPLC-DAD approach for simultaneous determination of chlorphenoxamine hydrochloride and caffeine with their related substances.

Ensuring the quality control of active pharmaceutical ingredients is crucial for drug products being introduced into the market. Even for established drugs, it is necessary to maintain a cutting-edge impurity control system. To analyze caffeine and chlorphenoxamine hydrochloride in their binary mixture, as well as theophylline and chlorphenoxamine N-oxide as related substances, a reversed phase-high performance liquid chromatography combined with a diode array detector system was created.

Fluorescence imaging approaches for eco-friendly determination of perampanel in human plasma and application for therapeutic drug monitoring.

Antiepileptic drugs are among the most common medications that require therapeutic drug monitoring (TDM). Indeed, TDM provides a realistic approach to adjust drug doses for epilepsy based on plasma concentrations to optimize its clinical outcome. The most common technique for TDM is high-performance liquid chromatography, which has a very low green profile among analytical techniques.

An eco-friendly separation-based framework for quantitative determination and purity testing of an antihypertensive ternary pharmaceutical formulation.

Designing new, verified methodologies with a focus on sustainability, analytical efficiency, simplicity, and the environment has become a major priority for pharmaceutical quality control units. In this way, sustainable and selective separation-based methodologies were designed and validated for the concurrent estimation of amiloride hydrochloride (AML), hydrochlorothiazide (HCT) and timolol maleate (TIM) in their fixed dose formulation (Moducren Tablets) along with hydrochlorothiazide potential impurities, salamide (DSA) and chlorothiazide (CT). The first method is a high performance thin layer chromatographic method (HPTLC-densitometry).

RP-HPLC Method for the Simultaneous Determination of a Quaternary Mixture of Propyphenazone, Flavoxate HCl and Two of Their Official Impurities with Dissolution Profiling of Their Tablets.

Background: Determination of different drugs in the presence of their impurities is now receiving attention from regulatory authorities such as the ICH and the United States Food and Drug Administration (USFDA).

Objective: To develop and validate a reversed-phase (RP)-HPLC method for the simultaneous separation and quantification of a quaternary mixture of propyphenazone, flavoxate HCl, and their official impurities; phenazone and 3-methylflavone-8-carboxylic acid, respectively. Then utilize the validated method as an in vitro methodology to monitor the rate of release of the active ingredients from Cistalgan® tablets.

Validated Chromatographic Methods for Simultaneous Determination of Calcipotriol Monohydrate and Betamethasone Dipropionate in the Presence of Two Dosage Form Additives.

Two chromatographic methods were developed, optimized and validated for simultaneous determination of calcipotriol monohydrate (CPM) and betamethasone dipropionate (BMD) in the presence of two dosage form additives named; butylated hydroxytoluene (BHT) and alpha-tocopherol (TOCO). The proposed methods were accurate, sensitive and specific. The first method based on using aluminum thin-layer chromatographic plates precoated with silica gel GF254 as a stationary phase and chloroform-ethyl acetate-toluene (5:5:3, by volume) as a developing system.

Simultaneous determination of Fluticasone propionate and Azelastine hydrochloride in the presence of pharmaceutical dosage form additives.

Fluticasone propionate (FLU) and Azelastine hydrochloride (AZE) are co-formulated with phenylethyl alcohol (PEA) and Benzalkonium chloride (BENZ) (as preservatives) in pharmaceutical dosage form for treatment of seasonal allergies. Different spectrophotometric methods were used for the simultaneous determination of cited drugs in the dosage form. Direct spectrophotometric method was used for determining of AZE, while Derivative of double divisor of ratio spectra (DD-RS), Ratio subtraction coupled with ratio difference method (RS-RD) and Mean centering of the ratio spectra (MCR) are used for the determination of FLU.

Advanced stability indicating chemometric methods for quantitation of amlodipine and atorvastatin in their quinary mixture with acidic degradation products.

Two advanced, accurate and precise chemometric methods are developed for the simultaneous determination of amlodipine besylate (AML) and atorvastatin calcium (ATV) in the presence of their acidic degradation products in tablet dosage forms. The first method was Partial Least Squares (PLS-1) and the second was Artificial Neural Networks (ANN). PLS was compared to ANN models with and without variable selection procedure (genetic algorithm (GA)).

Mean centering of double divisor ratio spectra, a novel spectrophotometric method for analysis of ternary mixtures.

A novel spectrophotometric method was developed for determination of ternary mixtures without previous separation, showing significant advantages over conventional methods. The new method is based on mean centering of double divisor ratio spectra. The mathematical explanation of the procedure is illustrated.

Continuous Wavelet Transform, a powerful alternative to Derivative Spectrophotometry in analysis of binary and ternary mixtures: A comparative study.

A comparative study was established between two signal processing techniques showing the theoretical algorithm for each method and making a comparison between them to indicate the advantages and limitations. The methods under study are Numerical Differentiation (ND) and Continuous Wavelet Transform (CWT). These methods were studied as spectrophotometric resolution tools for simultaneous analysis of binary and ternary mixtures.

Novel potentiometric application for the determination of pantoprazole sodium and itopride hydrochloride in their pure and combined dosage form.

Three sensitive and selective polyvinyl chloride (PVC) matrix membrane electrodes were developed and investigated. Sensor I was developed using tetraheptylammonium bromide (THB) as an anion exchanger with 2-nitrophenyl octyl ether (2-NPOE) as a plasticizer for the determination of the anionic drug pantoprazole sodium sesquihydrate (PAN). To determine the cationic drug itopride hydrochloride (ITH), two electrodes (sensors II and III) were developed using potassium tetrakis(4-chlorophenyl) borate (KTCPB) as a cation exchanger with dioctyl phthalate (DOP) as a plasticizer.

Different signal processing techniques of ratio spectra for spectrophotometric resolution of binary mixture of bisoprolol and hydrochlorothiazide; a comparative study.

Five signal processing techniques were applied to ratio spectra for quantitative determination of bisoprolol (BIS) and hydrochlorothiazide (HCT) in their binary mixture. The proposed techniques are Numerical Differentiation of Ratio Spectra (ND-RS), Savitsky-Golay of Ratio Spectra (SG-RS), Continuous Wavelet Transform of Ratio Spectra (CWT-RS), Mean Centering of Ratio Spectra (MC-RS) and Discrete Fourier Transform of Ratio Spectra (DFT-RS). The linearity of the proposed methods was investigated in the range of 2-40 and 1-22 μg/mL for BIS and HCT, respectively.

Simultaneous determination of a binary mixture of pantoprazole sodium and itopride hydrochloride by four spectrophotometric methods.

Four simple, sensitive, accurate and precise spectrophotometric methods were developed for the simultaneous determination of a binary mixture containing Pantoprazole Sodium Sesquihydrate (PAN) and Itopride Hydrochloride (ITH). Method (A) is the derivative ratio method ((1)DD), method (B) is the mean centering of ratio spectra method (MCR), method (C) is the ratio difference method (RD) and method (D) is the isoabsorptive point coupled with third derivative method ((3)D). Linear correlation was obtained in range 8-44 μg/mL for PAN by the four proposed methods, 8-40 μg/mL for ITH by methods A, B and C and 10-40 μg/mL for ITH by method D.

Different approaches in Partial Least Squares and Artificial Neural Network models applied for the analysis of a ternary mixture of Amlodipine, Valsartan and Hydrochlorothiazide.

Different chemometric models were applied for the quantitative analysis of Amlodipine (AML), Valsartan (VAL) and Hydrochlorothiazide (HCT) in ternary mixture, namely, Partial Least Squares (PLS) as traditional chemometric model and Artificial Neural Networks (ANN) as advanced model. PLS and ANN were applied with and without variable selection procedure (Genetic Algorithm GA) and data compression procedure (Principal Component Analysis PCA). The chemometric methods applied are PLS-1, GA-PLS, ANN, GA-ANN and PCA-ANN.

Comparative study between derivative spectrophotometry and multivariate calibration as analytical tools applied for the simultaneous quantitation of Amlodipine, Valsartan and Hydrochlorothiazide.

Four simple, accurate and specific methods were developed and validated for the simultaneous estimation of Amlodipine (AML), Valsartan (VAL) and Hydrochlorothiazide (HCT) in commercial tablets. The derivative spectrophotometric methods include Derivative Ratio Zero Crossing (DRZC) and Double Divisor Ratio Spectra-Derivative Spectrophotometry (DDRS-DS) methods, while the multivariate calibrations used are Principal Component Regression (PCR) and Partial Least Squares (PLSs). The proposed methods were applied successfully in the determination of the drugs in laboratory-prepared mixtures and in commercial pharmaceutical preparations.

Three different methods for determination of binary mixture of Amlodipine and Atorvastatin using dual wavelength spectrophotometry.

Three simple, specific, accurate and precise spectrophotometric methods depending on the proper selection of two wavelengths are developed for the simultaneous determination of Amlodipine besylate (AML) and Atorvastatin calcium (ATV) in tablet dosage forms. The first method is the new Ratio Difference method, the second method is the Bivariate method and the third one is the Absorbance Ratio method. The calibration curve is linear over the concentration range of 4-40 and 8-32 μg/mL for AML and ATV, respectively.

Membrane electrodes for the determination of glutathione.

Four glutathione (GSH)-selective electrodes were developed with different techniques and in different polymeric matrices. Precipitation-based technique with bathophenanthroline-ferrous as cationic exchanger in polyvinyl chloride (PVC) matrix was used for sensor 1 fabrication. beta-Cyclodextrin (beta-CD)-based technique with either tetrakis(4-chlorophenyl)borate (TpClPB) or bathophenanthroline-ferrous as fixed anionic and cationic sites in PVC matrix was used for fabrication of sensors 2 and 3, respectively.

High performance liquid chromatographic and thin layer densitometric methods for the determination of risperidone in the presence of its degradation products in bulk powder and in tablets.

Two reproducible stability indicating methods were developed for the determination of risperidone (RISP) in presence of its degradation products in pure form and in tablets. The first method was based on reversed phase high performance liquid chromatography (HPLC), on Lichrosorb RP C 18 column (250 mm i.d.

Stability indicating reversed-phase high-performance liquid chromatographic and thin layer densitometric methods for the determination of ziprasidone in bulk powder and in pharmaceutical formulations.

Two sensitive and reproducible methods were developed and validated for the determination of ziprasidone (ZIP) in the presence of its degradation products in pure form and in pharmaceutical formulations. The fi rst method was based on reversed-phase high-performance liquid chromatography (HPLC), on a Lichrosorb RP C(18) column using water:acetonitrile:phosphoric acid (76:24:0.5 v/v/v) as the mobile phase at a fl ow rate of 1.

Derivative spectrophotometric and fluorimetric methods for determination of rofecoxib in tablets and in human plasma in presence of its photo-degradation product.

Rofecoxib (I) has been determined in the presence of its photo-degradation product (II) using first derivative spectrophotometry ((1)D) and first derivative of the ratio spectra ((1)DD) by measuring the amplitude at 316.3 and 284 nm for (1)D and (1)DD, respectively. (I) can be determined in the presence of up to 70% and 80% of (II) by the (1)D and (1)DD, respectively.

Derivative spectrophotometric, thin layer chromatographic-densitometric and high performance liquid chromatographic determination of trifluoperazine hydrochloride in presence of its hydrogen peroxide induced-degradation product.

Three methods are presented for the determination of trifluoperazine HCl in presence of its hydrogen peroxide induced degradation product. The first method was based on measurement of first (1D) and second (2D) derivative amplitudes of trifluoperazine HCl in 0.1 N hydrochloric acid at the zero crossing point of its sulfoxide derivative, main degradation product, (at 268.