Ragab Said

Comparative Study Between Zero-Order Spectra-Processing and Ratio Spectra-Manipulating Methods Applied for the Determination of Isoxsuprine Hydrochloride in the Presence of Its Oxidative Degradation Product

Four accurate, precise, and validated stability-indicating spectrophotometric methods handling either zero-order spectra or ratio spectra have been developed and compared for the analysis of isoxsuprine hydrochloride (ISX) in the presence of its oxidative degradation product. The first two methods processed zero-order spectra, namely graphical absorbance ratio or Q-Analysis and area under the curve, whereas the third and fourth methods manipulated ratio spectra, namely the ratio difference spectrophotometric method and derivative ratio. The proposed methods showed good linearity in the range of 2-23 µg/mL. The methods were tested for specificity using laboratory-prepared mixtures containing the drug and its degradation product. The proposed methods were applied for the determination of ISX in Vascular tablets and the obtained results were acceptable, with small percentage RSD values. The validity of the proposed procedures was further assessed by applying the standard addition technique, which showed no interference from excipients. The obtained results were statistically compared with those obtained by the reported method, showing no significant differences when t- and F-tests were applied.

Comparative Study Between Three Different Methods Manipulating the Ratio Spectra Applied for the Analysis of Labetalol Hydrochloride in the Presence of its Oxidative Degradation Product

Abstract Three ratio spectra manipulating methods have been established for the analysis of labetalol hydrochloride (LBT) in the presence of its oxidative degradation product (DLBT) namely; ratio difference spectrophotometric method (RDSM), derivative ratio (1DD) and mean centering (MC). The proposed methods were found to be accurate and precise over the linearity ranges from 15–120 μg/ml. Validation of the methods were performed in accordance with ICH guideline and the specificity was assessed by analyzing synthetic mixtures containing the drug and its degradation product. The proposed methods were applied for the determination of LBT in Labipress® tablets. Satisfactory results were obtained in good agreement with the label claim. The obtained results were statistically compared to those obtained by the official method showing no significant differences by applying t-test and F-test.

A comparative study of different aspects in manipulating ratio spectra used for the analysis of cefradine in the presence of its alkaline degradation product

Six stability-indicating UV-spectrophotometric methods manipulating ratio spectra were utilized for the analysis of cefradine in presence of its alkaline degradate. These methods are different forms of transformations; ratio difference, mean centering, derivative ratio using numerical differentiation, derivative ratio using Savitsky-Golay filter, continuous wavelet transform and derivative continuous wavelet transform. Water was used as a solvent and the linearity ranges were 6-26 μg/mL. Determination of accuracy and precision for the suggested procedures were executed. Assessment of specificity was run through analyzing laboratory prepared mixtures containing cefradine and its alkaline degradate. The suggested methods were useful for cefradine estimation in tablets. Statistically, the outputs obtained from the recommended and published methods reveal no significant differences.

First derivative synchronous fluorescence spectroscopy for the determination of Gatifloxacin in presence of its oxidative degradation product: Application to pharmaceutical preparation

A highly accurate and precise spectrofluorimetric method was established for quantitation of Gatifloxacin in pure material, pharmaceutical formulations and in the existence of its oxidative degradation product. The emission was recorded at 487 nm after the excitation at 290 nm. Using micelle, sodium dodecyl sulphate (SDS), enhanced fluorescence intensity of Gatifloxacin-SDS complex. The optimization of numerous experimental conditions was carried out. The improved emission showed a suitable linear correlation between derivative synchronous fluorescence power and concentration of Gatifloxacin over the range of 10 to 100 ng/mL with a determination coefficient equals 0.9996. Studying cytotoxicity and antimicrobial susceptibility for oxidative degradation product of Gatifloxacin was carried out using Gatifloxacin as a control. In comparison, the proposed method presented a superior sensitivity and enhanced stability over the reported method.

Disposable gold nanoparticle functionalized and bare screen-printed electrodes for potentiometric determination of trazodone hydrochloride in pure form and pharmaceutical preparations

In the present study, screen-printed electrodes unmodified and chemically modified with gold nanoparticles were used as sensitive electrochemical sensors for the determination of trazodone hydrochloride. The sensors were based on the use of a tetraphenylborate ion association complex as an electroactive material in screen-printed electrodes with dioctyl phthalate (DOP) as a solvent mediator modified with gold nanoparticles which improve the electrode conductivity and enhance the surface area. The sensors displayed a stable response for 5, 6 and 7 months with a reproducible potential and linear response over the concentration range 1 × 10−5–1 × 10−2 mol L−1 at 25 ± 1 °C with Nernstian slopes of 57.50 ± 0.66, 58.30 ± 0.45 and 59.05 ± 0.58 mV per decade and detection limits of 7.9 × 10−6, 7.6 × 10−6 and 6.8 × 10−6 mol L−1 for sensor 1, 2 and 3 respectively. The analytical performance of the screen printed electrodes in terms of selectivity coefficients for trazodone hydrochloride relative to the number of potentially interfering substances was investigated. The proposed method has been applied successfully for the analysis of the drug in its pure and dosage forms and there is no interference from any common pharmaceutical additives.

Development and Validation of Spectrophotometric Methods Manipulating Ratio Spectra for Determination of Tetramisole Hydrochloride in the Presence of its Alkali-Induced Degradation Product

The aim of this work is to develop and validate simple, sensitive, selective and cost effective spectrophotometric methods for the determination of tetramisole hydrochloride in the presence of its alkali-induced degradation product without preliminary separation. These methods namely ratio difference [11,12], derivative ratio [13,14], mean centering [15,16] and continuous wavelet transform [17,18].

Application of TLC densitometric method for simultaneous estimation of binary mixture of phenazopyridine hydrochloride and trimethoprim in their tablet dosage form

Phenazopyridine hydrochloride (PHZ), [2, 6-diamino-3(phenylazo) pyridine hydrochloride] Figure 1A exerts an analgesic effect on the mucosa of the urinary tract and provides symptomatic relief of pain in conditions such as cystitis and urethritis. It is given in conjunction with an antibacterial agent for the treatment of urinary tract infections.1 Trimethoprim (TMP), [5-(3,4,5-Trimethoxybenzyl) pyrimidine-2,4-diamine] Figure 1B exerts antibacterial effect that is used for the treatment of infections due to sensitive organisms, including gastro-enteritis and respiratory tract infections, and in particular for the treatment and prophylaxis of urinary tract infections.1

RP- HPLC and TLC- densitometric methods for determination of oxfendazole in the presence of its alkali -induced degradation product

Oxfendazole chemically known as: [5-(Phenylsulfinyl)-1Hbenzimidazol-2-yl] carbamic acid methyl ester1 Figure 1. It is a benzimidazole carbamate anthelmintic used in veterinary medicine.2 Different analytical techniques were applied for quantitative estimation of oxfendazole including potentiometric titration,3,4 radio immunoassay,5 spectrophotometric methods6 and HPLC methods even alone or in presence of other compounds.7–17 Oxfendazole is an amide group containing compound that made it highly sensitive to hydrolytic degradation in basic conditions with the production of the degradation product 2-amino-5-Phenylsulfinyl benzimidazole. There is no stability indicating analytical methods were reported for determination of oxfendazole in presence of its degradation product. The aim of this work is to develop and validate simple, sensitive and selective chromatographic methods for the determination of oxfendazole in presence of its alkali-induced degradation product (2-amino-5-Phenylsulfinyl benzimidazole) without preliminary separation. The proposed methods were found to be fast and simple and can be used for its routine analysis in quality control laboratories.

Simultaneous Spectrophotometric Estimation of Triamterene and Xipamide in Pure Form and Pharmaceutical Formulation by Iso-absorptive Point Dependent Methods

Abstract The present work represents a simple, accurate, selective and sensitive UV-spectro-photometric methods for simultaneous estimation of xipamide and triamterene in pure and combined dosage form. The proposed methods are based on presence of iso-absorptive point. These methods include absorbance subtraction, amplitude modulation, Q analysis and absorbance ratio method. The methods have been validated for linearity, accuracy and precision and found to be rapid, precise and economical.

Kinetic Spectrophotometric and Spectrofluorimetric Methods for the Analysis of Olanzapine Using4-chloro-7-nitrobenzofurazan

Abstract Simple, accurate, sensitive and low cost spectrophotometric and spectrofluorimetric methods were developed for the determination of olanzapine (OLZ) using 4 chloro 7 nitrobenzofurazan (NBD-Cl) associated with kinetic study, either in pure form or in pharmaceutical preparation. In this work, OLZ was determined after reaction with NBD-Cl in the presence of 0.1M sodium bicarbonate at 90°C for 30 minutes. The reaction product was measured spectrophotometrically at 463 nm or spectrofluorimetrically at 540 nm after excitation at 460 nm. The calibration curves were linear in the range of 1-5.5 μg/mL using spectrophotometric method and 0.1-0.55 μg/ mL when spectrofluorimetric method was applied. The methods were applied successfully for commercial dosage form. The obtained results were statistically agreed with those obtained by the reported method. Kinetic determination of OLZ by rate constant and the fixed concentration methods was carried out, but the fixed time method proves to be more applicable.