Isoquinoline-based intrinsic fluorescence assessment of erythropoiesis-stimulating agent, Roxadustat (FG-4592), in tablets: applications to content uniformity and human plasma evaluation.

In the present study, a first validated and green spectrofluorimetric approach for its assessment and evaluation in different matrices was investigated. After using an excitation wavelength of 345 nm, Roxadustat (ROX) demonstrates a highly native fluorescence at an emission of 410 nm. The influences of experimental factors such as pH, diluting solvents, and different organized media were tested, and the most appropriate solvent choice was ethanol. It was confirmed that there was a linear relationship between the concentration of ROX and the relative fluorescence intensity in the range 60.0-1000.0 ng ml-1, with the limit of detection and limit of quantitation, respectively, being 17.0 and 53.0 ng ml-1. The mean recoveries % [±standard deviation (SD), n = 5] for pharmaceutical preparations were 100.11% ± 2.24%, whereas for plasma samples, they were 100.08 ± 1.08% (±SD, n = 5). The results obtained after the application of four greenness criteria, Analytical Eco-Scale metric, NEMI, GAPI, and AGREE metric, confirmed its eco-friendliness. In addition, the whiteness meter (RGB12) confirmed its level of sustainability. The International Council for Harmonisation (ICH) criteria were used to verify the developed method through the study in both spiked plasma samples and content uniformity evaluation. An appropriate standard for various applications in industry and quality control laboratories was developed.

New Chromatographic Techniques for Sensitive Mebendazole Quantification in the Presence of Degraded Product, Commercial Tablets Application, and Greenness Assessment.

BACKGROUND: Before it spreads to other tissues, mebendazole (MBZ), a highly effective broad-spectrum anthelmintic, is used to treat worm infestations caused by roundworms, hookworms, whipworms, threadworms (pinworms), and the gastrointestinal form of trichinosis. OBJECTIVE: The development of new methods for sensitive quantification of MBZ in the presence of its degraded product is the main objective of the presented research. METHOD: Validated chromatographic techniques with high sensitivity (HPTLC and UHPLC) are used. The HPTLC method was adopted on silica gel HPTLC F254 plates using ethanol, ethyl acetate, and formic acid (3: 8: 0.05, by volume) as a developing system. Furthermore, the UHPLC method is a green isocratic method with a mobile phase containing methanol and 0.1% sodium lauryl sulphate (20:80, v/v). RESULTS: The suggested chromatographic methods are greener than the reported ones in terms of the used greenness assessment methods. To validate the developed methods, International Council on Harmonization (ICH/Q2) guidelines were followed. Successful application of the proposed methods was revealed by the simultaneous analysis of MBZ and its major degradation product, 2-amino-5-benzoylbenzimidazole (ABB). The linear ranges were 0.2-3.0, 0.1-2.0 µg/band for the HPTLC method and 2.0-50, 1.0-40 µg/mL for the UHPLC method for MEB and ABB, respectively. CONCLUSIONS: The suggested methods were used to analyze the studied drug in its commercial tablets. Both pharmacokinetic studies and quality control laboratories can make use of the suggested techniques. HIGHLIGHTS: Green and accurate HPTLC and UHPLC methods for the determination of MBZ and its major degradation products.

Environmental impact of the reported chromatographic methods for the determination of the first FDA-Approved therapy for COVID-19 Patients, Remdesivir: A comparative study.

Remdesivir (REM) is considered the first therapeutic option approved by US Food and Drug Administration (FDA) for clinical care in case of hospitalized patients suffering in COVID-19 epidemic. In the presented multilateral comparative search, four eco friendlessness approaches -National Environmental Methods Index (NEMI), Eco-Scale Assessment (ESA), Green Analytical Procedure Index (GAPI), and Analytical Greenness metric (AGREE) are tested to assess 16 analytical chromatographic procedures reported for the analysis of the commonly used antiviral drug; Remdesivir (REM). The values of testing more than one approach when estimating the eco-friendly characters for analytical methods are illustrated in this study. On the light of the outcomes, ESA and AGREE approaches are recommended as they are easily applied and digitally presented. Furthermore, GAPI is also a reliable tool in terms of comprehensiveness for the whole analytical procedures, from sampling till the final assessment. NEMI is the easiest and fastest greenness evaluation tool; however, the information it provides is particularly of limited scope and sometimes inaccurate. To ensure greenness of chromatographic analytical methods, there must be clear planning beforehand, to reduce chemical hazards sent to environment. Additionally, it is highly recommended in method validation protocols to consider the greenness of a given analytical procedure before releasing to routine use. The LC-MS/MS analysis for the active metabolite of REM (Nuc) reported by Avataneo et al. and Du et al. proved to be the best bio-analytical methods regarding the environmental aspects depending on the GAPI and AGREE tools. However, the HPLC method for REM analysis in intravenous solution reported by Jitta et al. proved to be the greenest analytical method for determination of REM in the pharmaceutical dosage forms according to the ESA, GAPI, and AGREE tools.

The convenient use of fluorescamine for spectrofluorimetric quantitation of pramipexole in pure form and pharmaceutical formulation; application to content uniformity testing.

Pramipexole is a selective dopamine receptor agonist which is used in the treatment of Parkinson's disease and restless legs syndrome. The present work illustrates the development and validation of a sensitive and selective spectrofluorometric method for quantitation of pramipexole (PMP) through its interaction with fluorescamine at pH 7.5 using aqueous borate buffer to produce a highly fluorescent product. The fluorescent intensity of the formed product was measured at 480 nm after excitation at 391 nm. Experimental factors that could influence the formation, stability and the fluorescence intensity of the formed product were investigated and optimized. The linearity of the proposed method was achieved in the concentration range of 0.05-2.0 µg/mL. The quantitation and detection limits were 47 and 15 ng/mL, respectively. The proposed method has been validated in respect to guidelines of ICH and pharmaceutical tablets of PMP were successfully analyzed. Moreover, the method was applied for studying the content uniformity test according to the guidelines of United States Pharmacopeia.

Development and validation of stability indicating chromatographic methods for simultaneous determination of citicoline and piracetam.

Citicoline and piracetam were subjected separately to different stress conditions as recommended by the international conference on harmonization. In addition, new stability indicating thin layer chromatographic and ultra high performance liquid chromatographic methods have been developed and validated for simultaneous determination of citicoline and piracetam in presence of their degradation products. Separation on the proposed thin layer chromatographic method was carried out using a developing system containing methanol:chloroform:ammonium chloride buffer (9:1:2, v/v/v) on silica gel plates at 230 nm. On the other hand, the mobile phase in the ultra high performance liquid chromatographic method was composed of water (containing 0.1% triethylamine):ethanol (92:8, v/v). The flow rate was 1 mL/min and ultraviolet detection was at 230 nm. Moreover, results of the developed methods were statistically compared to those obtained by the reported high-performance liquid chromatography method and no significant difference between them was found. The greenness profile of ultra high performance liquid chromatographic method was assessed and compared with those of the previously published high-performance liquid chromatography methods, it was noticed that the proposed ultra high performance liquid chromatographic method more environmentally friendly and greener than other methods.

Spectrofluorimetric approach for determination of citicoline in the presence of co-formulated piracetam through fluorescence quenching of eosin Y.

A simple, sensitive, and precise spectrofluorimetric method has been developed and validated for quantitation of citicoline in its pharmaceutical formulations. The proposed method based on quantitative quenching effect of citicoline on the native fluorescence of Eosin Y via developing of a binary complex reaction between the cited drug and Eosin Y in acidic medium using acetate buffer pH = 3.6. The quenching of the fluorescence of eosin was measured at 540 nm after excitation at 518 nm. Calibration graph was achieved in the range of 300-3000 ng/mL with 0.9996 as correlation coefficient and 291.0 and 93.86 ng/mL as quantitation and detection limits, respectively. The developed method considered as the first developed spectrofluorimetric one for quantitation of citicoline with high sensitivity and validated according to ICH guidelines. The selectivity of the proposed method was investigated by studying the interference of piracetam as co-formulated drug with CIT in pharmaceutical formulation, therefore the developed method could be used for routine quality control of citicoline in its pharmaceutical formulations either alone or in combination with piracetam.

Innovative spectrofluorometric protocol based on micro-environment improvement for determination of Quetiapine in dosage forms and rat plasma.

Quetiapine (QUT) is an atypical antipsychotic drug indicated for the treatment of schizophrenia and acute manic episodes associated with bipolar disorders. A simple, rapid, and highly sensitive micellar spectrofluorometric method has been developed and validated for quantitation of QUT in its pharmaceutical formulations with application to content uniformity test, in presence of its degradation product and in rat plasma. The proposed method was based on the enhancement of the fluorescence intensity of QUT in 2% v/v tween 80 micellar solution. The fluorescence intensity was measured at 372 nm after excitation at 261 nm. A linear relationship was achieved between the fluorescence intensity and the drug concentration in the range of 20-1000 ng/mL with 18.5 and 6.3 ng/mL as limits of quantitation and detection, respectively. The proposed method was extended to study the stability of QUT after its exposure to different forced degradation conditions such as; acidic, alkaline, oxidative, photolytic and thermal conditions according to ICH guidelines. The study revealed that QUT is stable under all the of these conditions except the oxidative one. Furthermore, the high sensitivity of the micellar method permits its application for determination of QUT in rat plasma with good percentage recovery as well as determination of Cmax.

Stability-Indicating TLC-Densitometric and HPLC Methods for the Simultaneous Determination of Piracetam and Vincamine in the Presence of Their Degradation Products.

Newly established TLC-densitometric and RP-HPLC methods were developed and validated for the simultaneous determination of Piracetam (PIR) and Vincamine (VINC) in their pharmaceutical formulation and in the presence of PIR and VINC degradation products, PD and VD, respectively. The proposed TLC-densitometric method is based on the separation and quantitation of the studied components using a developing system that consists of chloroform-methanol-glacial acetic acid-triethylamine (8 + 2 + 0.1 + 0.1, v/v/v/v) on TLC silica gel 60 F254 plates, followed by densitometric scanning at 230 nm. On the other hand, the developed RP-HPLC method is based on the separation of the studied components using an isocratic elution of 0.05 M KH2PO4 (containing 0.1% triethylamine adjusted to pH 3 with orthophosphoric acid)-methanol (95 + 5, v/v) on a C8 column at a flow rate of 1 mL/min with diode-array detection at 230 nm. The developed methods were validated according to International Conference on Harmonization guidelines and demonstrated good accuracy and precision. Moreover, the developed TLC-densitometric and RP-HPLC methods are suitable as stability-indicating assay methods for the simultaneous determination of PD and VD either in bulk powder or pharmaceutical formulation. The results were statistically compared with those obtained by the reported RP-HPLC method using t- and F-tests.