scholarly journals Selective and Stability-Indicating Methods for the Simultaneous Determination of Mexiletine Hydrochloride and/or Its Related Substance: 2,6-Dimethylphenol

2008 ◽  
Vol 91 (4) ◽  
pp. 720-730
Author(s):  
Tarek S Belal ◽  
Rim S Haggag ◽  
Rasha A Shaalan
Keyword(s):  
Sodium Dodecyl ◽  
Coupling Reaction ◽  
Parent Drug ◽  
Related Substance ◽  
Selective Determination ◽  
Stability Indicating ◽  
Spectrophotometric Methods ◽  
First Derivative ◽  
The Stability

Abstract Four simple, rapid, sensitive, and selective analytical procedures were developed for determination of mexiletine hydrochloride (MX) and/or its related substance: 2,6-dimethylphenol (DMP). The latter is a synthetic impurity for which a maximum pharmacopeial limit is defined. The first method depends on derivative-ratio spectrophotometry, for which the first-derivative signals of the ratio spectra at 259 nm ( = 3 nm) are selected for the determination of MX. The second method is based on the spectrofluorometric measurement of MX in alkaline solution in the presence of 15 mM sodium dodecyl sulfate micellar medium at 292 nm (Ex 260 nm). The third method is based on liquid chromatographic (LC) separation of MX and DMP on an RP-C8 column with a mobile phase consisting of 50 mM Na2HPO4acetonitrile (60 + 40, adjusted to pH 2.4), and quantification of the analytes is achieved with UV detection at 212 nm based on peak area. The fourth method uses the coupling reaction of DMP with 2,6-dibromoquinone-4-chlorimide (DBQC) in borate buffer to form an intensely colored product that was spectrophotometrically measured using first-derivative amplitudes at 670 nm ( = 6nm) for the determination of DMP. Different variables affecting each method were carefully investigated and optimized. The reliability and analytical performance of the proposed methods, including linearity, range, precision, accuracy, and detection and quantitation limits, were statistically validated. The first 3 methods were successfully applied for the stability-indicating determination of MX in laboratory-prepared mixtures with DMP, as well as for the determination of MX in capsules. Also, the LC and the DBQC spectrophotometric methods permitted the selective determination of DMP in the presence of a large excess of the parent drug at or near the pharmacopeial limit (0.11).

scholarly journals Validated Stability Indicating HPTLC, UHPLC and UV-Spectrophotometric Techniques for the Determination of Bepotastine Besilate in Presence of Its Oxidative Degradate

2019 ◽  
pp. 1-14 ◽  
Author(s):  
Marwa Mohammed Soliman ◽  
Manal Kamal Darwish ◽  
Sawsan Abdel-Moneem Abdel-Razeq
Keyword(s):  
High Performance ◽  
Oxidative Degradation ◽  
Pharmaceutical Formulations ◽  
Stability Indicating ◽  
Spectrophotometric Methods ◽  
First Derivative ◽  
Ratio Difference ◽  
Ich Guidelines ◽  
Developing System

The study is aimed at developing methods which have a complete validation as stipulated in the ICH guidelines and to be applied for the determination of Bepotastine besilate (BB) in pure form and in pharmaceutical formulations in the presence of its oxidative degradation product. High performance thin layer chromatography (HPTLC), Ultra high performance liquid chromatography (UHPLC) and different spectrophotometric methods (first derivative, first derivative of ratio spectra and ratio difference are developed for simultaneous determination of bepotastine besilate in laboratory-prepared mixtures of bepotastine besilate with its oxidative degradate and in pharmaceutical formulations were used in the study design. Firstly, HPTLC was performed and separation occurred on silica gel 60 F254 plates, with butanol: ammonia (8:2, v/v) as a developing system. UHPLC in which separation occurred on a Kinetex C 18 column using methanol- 0.1% O-phosphoric acid - acetonitrile (70:20:10, by volume) as mobile phase, followed. And lastly was UV/Vis spectrophotometry which included first derivative determination of the drug at 252.6 nm, first derivative of ratio of peak amplitudes at 233.4, 250 and 275.6 nm and the ratio difference with the amplitude difference between (240 nm and 260 nm). Result showed that HPTLC method was applicable over the concentration range of 0.5-5 μg / band, while UHPLC method was linear over the concentration 2- 12 μg/mL and spectrophotometric methods were linear over the concentration range 20-120 μg/mL for bepotastine besilate. The proposed three techniques are quite accurate and precise. They can be used for routine analysis of bepotastine besilate in pharmaceutical formulation and stability indicating methods.

SIMPLE AND HIGHLY SELECTIVE DIRECT STABILITY INDICATING ULTRAVIOLET AND INDIRECT VISIBLE SPECTROPHOTOMETRIC METHODS FOR DETERMINATION OF ENROFLOXACIN IN PHARMACEUTICALS

2021 ◽  
Vol 88 (6) ◽  
pp. 982-992
Author(s):  
N. Rajendraprasad
Keyword(s):  
Standard Addition ◽  
Uv Degradation ◽  
Degradation Study ◽  
Formation Reaction ◽  
Stability Indicating ◽  
Spectrophotometric Methods ◽  
The Stability ◽  
Simple Economic ◽  
Molar Extinction Coefficients

Three simple, economic, selective and accurate and precise spectrophotometric methods are developed for determination of enrofloxacin (EFX) in pharmaceuticals. Method A is based on the measurement of absorbance of EFX in 0.1M HOAc at 315 nm. The ketoxime formation reaction has been employed in method B, in which the absorbance measurement of EFX oxime product at 275 nm is described. The third method (Method C) is indirect one and is based on the oxidation of EFX by cerium(IV), reaction of unreacted cerium(IV) with p-toludine (p-TD) and measurement of coloured solution at 540 nm. The Beer’s law is obeyed in the concentration ranges of 1.2–24, 1–8, and 1–20 μg/mL EFX in methods A, B, and C, respectively, with the corresponding molar extinction coefficients of 1.52×104, 3.86×104, and 6.6×103 L/mol/cm. The regression coefficients of calibration lines are 0.9996, 0.9913, and –0.9965, in methods A, B, and C, respectively. The limits of detection (LOD) and quantification (LOQ) have also been reported for each method. The methods have been validated to check accuracy, precision, robustness and ruggedness. The application of the methods proposed to determine EFX in tablets has been described and the results have been compared with a standard method. The results of validation and application have been found to be with excellent agreement. The standard addition procedure has been adopted in recovery experiments to further ascertain the accuracy of the methods and the results of the experiments are well satisfied. The stability indicating ability of Method A has been studied by subjecting EFX to acid and alkaline hydrolysis, oxidative, thermal and UV degradation followed by measurement of absorbance of resultant EFX solutions at 315 nm. The results of degradation study indicated unsusceptible nature of EFX to any of the stress conditions.

scholarly journals Development and Validation of a Novel Stability-Indicating Reversed-Phase High-Performance Liquid Chromatography Method for Assay of Loratadine and Determination of Its Related Compounds

2010 ◽  
Vol 93 (3) ◽  
pp. 891-903 ◽  
Author(s):  
Jun Lu ◽  
Yu-Chien Wei ◽  
Robert J Markovich ◽  
Abu M Rustum
Keyword(s):  
High Performance ◽  
Sodium Dodecyl ◽  
Active Pharmaceutical Ingredient ◽  
Reversed Phase ◽  
Hplc Method ◽  
Chromatography Method ◽  
Stability Indicating ◽  
The Stability ◽  
Related Compounds

Abstract Loratadine is an important active pharmaceutical ingredient used in a wide variety of prescription and over-the-counter products for the treatment and relief of allergy symptoms. A novel stability-indicating gradient ion-pair RP-HPLC method for assay of loratadine and determination of both of its degradation compounds and process impurities has been developed. This method can separate loratadine from its eight structurally related compounds; it can also separate all of the related compounds from each other in less than 20 min. The stability-indicating capability of this method has been demonstrated by analyzing aged stability samples of loratadine. A 15 cm 4.6 mm id YMC-Pack Pro C18 HPLC column was the primary column and a 15 cm 4.6 mm id SunFire C18 column has been identified as an alternate (truly equivalent) column for this method. This gradient method uses mobile phases consisting of acetonitrile and an aqueous solution of 10 mM sodium acetate and 5 mM sodium dodecyl sulfate at pH 5.5. The new HPLC method was validated according to International Conference on Harmonization guidelines and proved to be suitable for routine QC use.

scholarly journals Stability-indicating derivative spectrophotometry method for the determination of biapenem in the presence of its degradation products

2011 ◽  
Vol 9 (1) ◽  
pp. 35-40 ◽  
Author(s):  
Judyta Cielecka-Piontek ◽  
Aran Lunzer ◽  
Anna Jelińska
Keyword(s):  
Degradation Products ◽  
Hplc Method ◽  
Subtraction Technique ◽  
Pharmaceutical Dosage Form ◽  
Zero Crossing ◽  
Stability Indicating ◽  
First Derivative ◽  
The Stability ◽  
Crossing Point

AbstractA first-derivative UV spectrophotometric method, with or without the subtraction technique, was developed for the determination of biapenem in pharmaceutical dosage form in the presence of its degradation products. The method was based on the measurement of first-derivative amplitudes at zero crossing point (λ = 312 nm) and the peak-to-zero technique and validated with regard to linearity, limits of detection and quantitation, selectivity and precision. The observed rate constants for the degradation of biapenem were comparable to those obtained in the stability-indicating HPLC method.

Development of Validated Stability Indicating HPTLC Method for Assay of Ozagrel and its Pharmaceutical Formulations

2018 ◽  
pp. 36-48 ◽  
Author(s):  
Vishal N Kushare ◽  
Sachin S Kushare
Keyword(s):  
High Performance ◽  
Linear Regression Analysis ◽  
Pharmaceutical Formulations ◽  
Base Hydrolysis ◽  
Assay Method ◽  
Related Substance ◽  
Stability Indicating ◽  
Regular Production ◽  
Hptlc Method

The present paper describes stability indicating high-performance thin-layer chromatography (HPTLC) assay method for Ozagrel in bulk drugs. The method employed TLC aluminium plates precoated with silica gel 60F-254 as the stationary phase. The solvent system consisted of toluene: methanol: triethylamine (6.5: 4.0: 0.1 v/v/v). The system was found to give compact spot for Ozagrel (Rf value of 0.40 ± 0.010). Densitometric analysis of Ozagrel was carried out in the absorbance mode at 280 nm. The linear regression analysis data for the calibration plots showed good linear relationship with r2 = 0.999 with respect to peak area in the concentration range 30 - 120 ng/spot. The developed HPTLC method was validated with respect to accuracy, precision, recovery and robustness. Also to determine related substance and assay determination of Ozagrel that can be used to evaluate the quality of regular production samples. The developed method can also be conveniently used for the assay determination of Ozagrel in pharmaceutical formulations. The limits of detection and quantitation were 4.069 and 12.332 ng/spot, respectively by height. Ozagrel was subjected to acid and alkali hydrolysis, oxidation, photochemical and thermal degradation. The drug undergoes degradation under acidic, basic, oxidation and heat conditions. This indicates that the drug is susceptible to acid, base hydrolysis, oxidation and heat. Statistical analysis proves that the method is repeatable, selective and accurate for the estimation of said drug. The proposed developed HPTLC method can be applied for identification and quantitative determination of Ozagrel in bulk drug and tablet formulation.

scholarly journals Analysis of some pharmaceuticals in the presence of their synthetic impurities by applying hybrid micelle liquid chromatography

2020 ◽  
Vol 18 (1) ◽  
pp. 377-390
Author(s):  
Dina El Sherbiny ◽  
Mary E. K. Wahba
Keyword(s):  
Liquid Chromatography ◽  
Sodium Dodecyl Sulfate ◽  
Phosphoric Acid ◽  
Mobile Phase ◽  
Sodium Dodecyl ◽  
Uv Detection ◽  
Stability Indicating ◽  
Photolytic Degradation ◽  
Amino Phenol ◽  
The Stability

AbstractA stability-indicating hybrid micelle liquid chromatography accompanied by UV detection was developed for the simultaneous analysis of either paracetamol (PCA) or pseudoephedrine hydrochloride (PSU) with their synthetic impurities. Mixture I contains PCA with p-amino phenol and p-nitro phenol, while mixture II involves the estimation of PSU with benzaldehyde and benzoic acid. Both mixtures were separated using a C18 column that was thermostatically maintained at 40°C and operating under a flow rate of 1.5 mL/min, applying UV detection at 240 nm for mixture I and 220 nm for mixture II. In both cases, the mobile phase consisted of 0.1 M sodium dodecyl sulfate, acetonitrile, and triethylamine (90:10:0.3, v/v/v) and adjusted to pH 4 (mixture I) or pH 3.7 (mixture II) using 2.0 M O-phosphoric acid. The proposed method was validated and successfully applied to assay different pharmaceuticals containing PCA or PSU. Moreover, the stability-indicating nature of the proposed method was proved through applying photolytic degradation procedures for PCA.

scholarly journals Charge Transfer Complexes of Ketotifen with 2,3-Dichloro-5,6-dicyano-p-benzoquinone and 7,7,8,8-Tetracyanoquodimethane: Spectroscopic Characterization Studies

Molecules ◽  
2021 ◽  
Vol 26 (7) ◽  
pp. 2039
Author(s):  
Gamal A. E. Mostafa ◽  
Ahmed Bakheit ◽  
Najla AlMasoud ◽  
Haitham AlRabiah
Keyword(s):  
Charge Transfer ◽  
Spectroscopic Characterization ◽  
Molar Ratio ◽  
Charge Transfer Complexes ◽  
Physical Parameters ◽  
Spectrophotometric Methods ◽  
Theoretical Approaches ◽  
The Stability ◽  
Ct Complexes

The reactions of ketotifen fumarate (KT) with 2,3-dichloro-5,6-dicyano-p-benzoquinone (DDQ) and 7,7,8,8-tetracyanoquinodimethane (TCNQ) as π acceptors to form charge transfer (CT) complexes were evaluated in this study. Experimental and theoretical approaches, including density function theory (DFT), were used to obtain the comprehensive, reliable, and accurate structure elucidation of the developed CT complexes. The CT complexes (KT-DDQ and KT-TCNQ) were monitored at 485 and 843 nm, respectively, and the calibration curve ranged from 10 to 100 ppm for KT-DDQ and 2.5 to 40 ppm for KT-TCNQ. The spectrophotometric methods were validated for the determination of KT, and the stability of the CT complexes was assessed by studying the corresponding spectroscopic physical parameters. The molar ratio of KT:DDQ and KT:TCNQ was estimated at 1:1 using Job’s method, which was compatible with the results obtained using the Benesi–Hildebrand equation. Using these complexes, the quantitative determination of KT in its dosage form was successful.

scholarly journals Three Different Spectrophotometric Methods for Simultaneous Determination of Pyriproxyfen and Chlorothalonil Residues in Cucumber and Cabbage Samples

2019 ◽  
Vol 2019 ◽  
pp. 1-11
Author(s):  
Shilan A. Omer ◽  
Nabil A. Fakhre
Keyword(s):  
Simultaneous Determination ◽  
Simultaneous Estimation ◽  
Zero Crossing ◽  
Spectrophotometric Methods ◽  
First Derivative ◽  
The Third ◽  
Mean Centering ◽  
Relative Standard ◽  
One Way Anova

In this study, three simple and accurate spectrophotometric methods for simultaneous determination of pyriproxyfen and chlorothalonil residues in cucumbers and cabbages grown in experimental greenhouse were studied. The first method was based on the zero-crossing technique measurement for first and second derivative spectrophotometry. The second method was based on the first derivative of the ratio spectra. However, the third method was based on mean centering of ratio spectra. These procedures lack any previous separation steps. The calibration curves for three spectrophotometric methods are linear in the concentration range of 1–30 μg·mL−1 and 0.5–7 μg·mL−1 for pyriproxyfen and chlorothalonil successively. The recoveries ranged from 82.12–97.40% for pyriproxyfen and 81.51–97.04% for chlorothalonil with relative standard deviations less than 4.95% and 5.45% in all instances for pyriproxyfen and chlorothalonil, respectively. The results obtained from the proposed methods were compared statistically by using one-way ANOVA, and the results revealed there were no significant differences between ratio spectra and mean centering methods with the zero-crossing technique. The proposed methods are successfully applied for the simultaneous estimation of the residue of both pesticides in cucumber and cabbage samples.

scholarly journals SYNTHESIS OF NEW SUBSTITUTED PROCAINE HYDROCHLORIDE COMPOUNDS AND THEIR USE IN SPECTROPHOTOMETRIC DETERMINATION OF TETRACYCLINE HYDROCHLORIDE THROUGH DIAZOTIZATION-COUPLING REACTIONS

2021 ◽  
Vol 18 (39) ◽  
pp. 14-32
Author(s):  
Hind Sadiq Al-WARD ◽  
Mouayed Qassssim AL-ABACHI ◽  
Mohammed Rifaat AHMED
Keyword(s):  
Stability Constant ◽  
Thermodynamic Parameters ◽  
Coupling Reaction ◽  
Water Soluble ◽  
Procaine Hydrochloride ◽  
Effect Of Temperature ◽  
Basic Medium ◽  
Fast Method ◽  
The Stability

Background: Tetracycline is one of the most important antibiotics. It is used to treat many different bacterial infections. It is often used in treating severe acne, or sexually transmitted diseases such as syphilis, gonorrhea, or chlamydia. In some cases, tetracycline is used when penicillin or another antibiotic cannot be used to treat serious infections such as the ones caused by Bacillus anthracis, Listeria, Clostridium, Actinomyces. Aim: synthesized a new novel reagent used to determine TCH spectrophotometrically by using diazonium and coupling reaction. Methods: Four new substituted procaine derivatives were prepared by simple organic methods using aniline derivatives. A spectrophotometric approach was established for the micro-determination of TCH. The stoichiometry was investigated using mole ratio and continuous variation methods, and the stability constant was also estimated. The ΔG, ΔH, and ΔS were determined as thermodynamic parameters for evaluating the effect of temperature on the reaction. Results: Substituted procaine derivatives were prepared, and o-hydroxy procaine seems to be the best reagent used to determine TCH by diazotization and coupling reaction. The result was a yellow water-soluble dye with a maximum absorbance of 380 nm. The reaction conditions were studied and optimized. Beers law was obeyed over a concentration range (2.5–50) μg.mL-1 for TCH. The molar absorptivity was (14.4669.103) L.mol-1.cm-1, and the detection limit was (0.5052) μg.mL-1. The stoichiometry of the formed product was found 1:1 (o-hydroxyprocaine: TCH). The stability constant indicated that the product formed was stable, and the thermodynamic parameters showed that the diazonium salt reaction was preferred to occur at a low temperature. Conclusions: a simple, accurate, and fast method was developed to determine TCH in pure form and pharmaceuticals by coupling the TCH with a newly synthesized procaine derivative reagent (o-hydroxy procaine) in a basic medium.

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