Application of different spectrofluorimetric methods for determination of lesinurad and allopurinol in pharmaceutical preparation and human plasma

Ecofriendly micellar mediated spectrofluorimetric method for ultrasensitive quantification of the antiparkinsonian drug safinamide in pharmaceutical formulation and spiked human plasma

A novel, highly sensitive and eco-friendly micellar-mediated spectrofluorimetric method was developed and validated for the determination of the novel antiparkinsonian drug safinamide mesylate in the presence of its related precursor impurity, 4-hydroxybenzaldehyde. The proposed approach relies on increasing the inherent fluorescence emission at 296 nm of safinamide, by forming hydrogen bonds between the mentioned drug and sodium dodecyl sulfate in the micellar system using 0.1 N HCl as a solvent, following excitation at 226 nm. A thorough investigation was conducted into the experimental factors affecting spectrofluorimetric behavior of the studied drug. A linearity plot of safinamide over the concentration range of 10.0-1000.0 ng/mL against the relative fluorescence intensities was established. The proposed method demonstrated excellent sensitivity down to the nano-gram level with detection and quantitation limits of 1.91 and 5.79 ng/mL, respectively. The studied drug was effectively determined in Parkimedine® Tablets. Furthermore, the proposed method allows for ultrasensitive quantification of safinamide in spiked human plasma, with satisfactory percentage recovery (98.97-102.28%). Additionally, the greenness assessment using the advanced green certificate classification approach, the complementary green analytical procedure index (Complex-GAPI), and the analytical GREEness metric approach (AGREE), along with the practicality check using the Blue Applicability Grade Index in addition to the all-inclusive overall whiteness evaluation using the RGB-12 model were carried out. The outcomes demonstrated the effectiveness and whiteness of the proposed technique. Clearly, the suggested approach has the advantages of being simple, requiring no pretreatment steps, and relying solely on direct measuring procedures.

Simultaneous determination of lesinurad and febuxostat in commercial fixed-dose combinations using a greener normal-phase HPTLC method

So far, no documented method for simultaneously analyzing lesinurad (LND) and febuxostat (FBX) has been reported for either traditional high-performance thin-layer chromatography (HPTLC) or a green HPTLC technique. In order to determine LND and FBX simultaneously in commercially available fixed-dose combo tablets, this study devised a normal-phase HPTLC method that is fast, sensitive, and green. The green eluents for the simultaneous analysis of LND and FBX were a mixture of ethyl acetate:ethanol:water at 70:20:10 (v/v/v) ratio. The new approach’s greenness was predicted utilizing four distinct greenness tools: the National Environmental Method Index, Analytical Eco-Scale, ChlorTox, and Analytical GREENness approaches, and the results revealed a significantly greener profile. The current method operated on a linear scale between 30 and 1,000 ng·band−1. It was confirmed that the current approach is sensitive, accurate, precise, robust, and green. The LND and FBX contents of commercially available tablet products A and B were found to be within the range of 100 ± 2%, indicating that the existing methodology for simultaneously determining LND and FBX in pharmaceutical combination products is applicable. The results of the current methodology indicated that LND and FBX could be consistently measured in pharmaceutical combination products simultaneously using the current approach.

Exploring the role of copper and zinc in chronic otitis media: A novel spectrofluorometric method for precise determination and association study

Chronic otitis media is a common condition characterized by fluid accumulation in the middle ear, leading to a perforated eardrum and persistent middle ear drainage. Despite its impact on global health, the role of heavy metals, particularly copper and zinc, in its development and progression remains understudied. Herein, a spectrofluorometric method was developed for the precise determination of copper and zinc in human plasma samples and investigate their association with chronic otitis media. The method involves the use of the fluorescent probe 6,7-dihydroxy-4-phenylcoumarin to selectively quantify copper through fluorescence quenching and zinc through fluorescence enhancement with a remarked bathochromic shift. The method was validated and exhibited good linearity over a concentration range of 100-3000 ng/mL for copper and 200-5000 ng/mL for zinc. Application of the method to healthy volunteers and patients with chronic otitis media revealed significantly decreased copper and zinc levels in patients with chronic otitis media compared to the healthy individuals. These findings shed light on the involvement of copper and zinc in the pathogenesis of chronic otitis media and open avenues for additional treatment approaches.

Innovative spectrofluorometric method for determination of harmaline and harmine in different matrices

Harmaline and harmine are naturally occurring closely related β-carboline alkaloids found in Peganum and Banisteriopsis plants. They have historical significance in traditional practices due to their potential psychoactive and therapeutic properties. Herein, a highly sensitive spectrofluorometric method was developed for the quantifying of harmaline and harmine in diverse matrices, including pure forms, seed samples, and spiked plasma. The procedures lie in addressing the challenge of overlapping fluorescence spectra exhibited by harmaline and harmine through the incorporation of hydroxypropyl-β-cyclodextrin, altering their chemical properties and fluorescence characteristics. Synchronous fluorescence measurements coupled with first derivative mathematical technique make it possible to distinguish between the harmaline and harmine at 419 and 456 nm, respectively. The method effectiveness is demonstrated through spectral analysis, optimization of the measurement conditions, adopting validation parameters and application to the pure form, seed samples and spiked human plasma. This methodology facilitates accurate determination of these alkaloids over the concentration range of 10─200 ng/mL. Thus, the developed approach provides a robust mean for the precise determination of harmaline and harmine, contributing to analytical chemistry's ongoing efforts to address complex challenges in quantification across diverse matrices.

Coupling of synchronous fluorescence spectroscopy with derivative amplitude outcomes for simultaneous determination of metoprolol succinate and olmesartan medoxomil in combined pharmaceutical preparation: Application in spiked human plasma

For the first time a spectrofluorimetric method had been achieved for the concurrent analysis of metoprolol succinate (MET) and olmesartan medoxomil (OLM). The approach depended on assessing the first order derivative (¹D) of the synchronous fluorescence intensity of the two drugs in aqueous solution at Δλ of 100 nm. The amplitudes of ¹D at 300 nm and 347 nm were measured for MET and OLM, respectively. The linearity ranges were 100-1000 ng/mL and 100-5000 ng/mL for OLM and MET, respectively. This approach is uncomplicated, repetitive, quick, and affordable. The results of analysis had been statistically verified. The validation assessments were carried out following the recommendations of The International Council for Harmonization (ICH). This technique could be employed to assess marketed formulation. The method was sensitive with limits of detection (LOD) of 32 ng/ml and 14 ng/mL for MET and OLM, respectively. Limits of quantitation (LOQ) were 99 ng/ml for MET and 44 ng/mL for OLM. So it can be applied to determine both drugs in spiked human plasma within the linearity ranges of 100-1000 ng/mL for OLM and 100-1500 ng/mL for MET.

Green adherent spectrophotometric determination of molnupiravir based on computational calculations; application to a recently FDA-approved pharmaceutical dosage form

Molnupiravir is an oral antiviral drug developed to provide significant benefit in reducing hospitalizations or deaths in mild COVID-19. Integrated green computational spectrophotometric method was developed for the determination of molnupiravir. Theoretical calculations were performed to predict the best coupling agent for efficient diazo coupling of molnupiravir. The binding energy between molnupiravir and various phenolic coupling agents, α-naphthol, β-naphthol, 8-hydroxyquinoline, resorcinol, and phloroglucinol, was measured using Gaussian 03 software based on the density functional theory method and the basis set B3LYP/6-31G(d). The results showed that the interaction between molnupiravir and 8-hydroxyquinoline was higher than that of other phenolic coupling agents. The method described was based on the formation of a red colored chromogen by the diazo coupling of molnupiravir with sodium nitrite in acidic medium to form a diazonium ion coupled with 8-hydroxyquinoline. The absorption spectra showed maximum sharp peaks at 515 nm. The reaction conditions were optimized. Beer's law was followed over the concentration range of 1-12 μg/ml molnupiravir. Job's continuous variation method was developed and the stoichiometric ratio of molnupiravir to 8-hydroxyquinoline was determined to be 1:1. The described method was successfully applied to the determination of molnupiravir in pure form and in pharmaceutical dosage form. The results showed that the proposed method has minimal environmental impact compared to previous HPLC method.

Different spectrophotometric methods for simultaneous determination of lesinurad and allopurinol in the new FDA approved pharmaceutical preparation; additional greenness evaluation

Lesinurad and allopurinol have been formulated in a combined dosage form providing a new challenge for the treatment of gout attacks. Two mathematical based spectrophotometric methods, area under the curve, and artificial neural networks have been developed for simultaneous determination of lesinurad and allopurinol in pure form and in combined pharmaceutical dosage form. Area under the curve has been utilized to resolve the spectral overlap between lesinurad and allopurinol. Values of area under the curve and area absorptivity were measured at two selected wavelength ranges of 242-250 nm and 255-265 nm. Two mathematically constructed equations have been used to determine the concentrations of the drugs under the study. Advanced chemometry based model, artificial neural network, has been developed utilizing the UV spectral data of lesinurad and allopurinol through various defined steps. A five-level, two-factor experimental design was used to construct 25 mixtures. Thirteen mixtures were used to set up the calibration model and 12 mixtures were used to construct a validation set. The artificial neural network model was optimized to enable precise spectrophotometric determination of the drugs under the study. The described mathematically bases spectrophotometric methods have been successfully applied to the determination of lesinurad and allopurinol in the new combined, Duzallo® tablets. Furthermore, the greenness of the described methods was assessed using four different tools namely, the national environmental method index, the analytical eco-scale, the green analytical procedure index and the AGREE evaluation method. The proposed methods showed more adherence to the greenness characters in comparison to the previously reported HPLC method.

Simultaneous spectrofluorimetic determination of remdesivir and simeprevir in human plasma

As new infectious mutations of SARS-CoV-2 emerged throughout the world, innovative therapies to counter the virus-altered drug sensitivities were urgently needed. Several antiviral options have been in clinical trials or in compassionate use for the treatment of SARS-CoV-2 infections in an attempt to minimize both clinical severity and viral shedding. Recent research indicated that simeprevir acts synergistically with remdesivir, allowing for a multiple-fold decrease in its effective dose when used at physiologically acceptable concentrations. The goal of this work is to develop a sensitive synchronous spectrofluorimetric approach to simultaneously quantify the two drugs in biological fluids. Using this method, remdesivir and simeprevir could be measured spectrofluorimetrically at 283 and 341 nm, respectively, without interference from each other using Δλ of 90 nm. The effect of various experimental parameters on the fluorescence intensity of the two drugs was extensively explored and optimized. For each of remdesivir and simeprevir, the method exhibited a linearity range of 0.10-1.10 μg/mL, with lower detection limits of 0.01 and 0.02 μg/mL and quantification limits of 0.03 and 0.05 μg/mL, respectively. The high sensitivity of the developed method permitted the simultaneous determination of both drugs in spiked plasma samples with % recoveries ranging from 95.0 to 103.25 with acceptable standard deviation values of 1.92 and 3.04 for remdesivir and simeprevir, respectively. The validation of the approach was approved by the International Council of Harmonization (ICH) guidelines.

Spectrofluorimetric quantitative analysis of favipiravir, remdesivir and hydroxychloroquine in spiked human plasma

Favipiravir, remdesivir and hydroxychloroquine have been suggested in COVID-19 Treatment Guidelines Panel of many countries. Synchronous spectrofluorometric measurement provides sensitive tool for resolving the overlapped spectra of multicomponent drugs through converting the wider spectra to narrower sharp spectra. This work introduces the first fluorescence spectroscopic method for quantitative analysis of favipiravir, remdesivir and hydroxychloroquine in spiked human plasma. Testing the fluorescence spectra of favipiravir, remdesivir and hydroxychloroquine shows severe overlap, which hinders the direct quantification of the cited drugs. To overcome the overlapping issue, the drugs under the study have been measured in the synchronous mode at Δλ = 60 nm. Favipiravir could be measured directly at 423 nm without interference of remdesivir or hydroxychloroquine. Synchronous measuring the cited drugs at Δλ = 130 nm with mathematical transforming to the first order derivative spectra allowing remdesivir and hydroxychloroquine at 384 nm and 394 nm, respectively without interference from favipiravir. Different factors affecting the spectrofluorometric measurement process have been verified. The drugs under the study have been successfully quantitatively analyzed in the spiked plasma using the proposed method.

Application of different quantitative analytical techniques for estimation of aspirin and omeprazole in pharmaceutical preparation

Several quantitative analytical methods were used to estimate aspirin and omeprazole in recently FDA-approved tablets. The first derivative of the ratio spectra was used to resolve the recorded overlapping spectra between aspirin and omeprazole. The first derivative of the ratio spectra of the studied drug mixtures was divided by a spectrum of a standard solution of omeprazole for the estimation of aspirin. Also, the first derivative of the ratio spectra of the studied drug mixtures was divided by a spectrum of the standard solution of aspirin for the estimation of omeprazole. For the simultaneous quantitative analysis of aspirin and omeprazole, the TLC densitometry technique was applied using TLC aluminum silica gel plates, toluene–acetonitrile–methanol (7:2:0.5, by volume) as the mobile phase, and UV detection at 272 nm. The advantages and disadvantages of the proposed techniques were discussed in the context of the results and the sensitivity limits of the methods. The proposed techniques were validated and successfully applied to the analysis of drugs in pure and pharmaceutical forms. A statistical comparison of the data obtained by the described methods with other data obtained by a previously published HPLC method was performed. The results agreed well with respect to the recommended statistical tests. Furthermore, the greenness of the described methods was assessed using different tools, the analytical eco-scale, the green analytical procedure index and the AGREE evaluation method. The proposed methods showed more adherence to the greenness characters in comparison to the previously reported HPLC method.

Quantitative analysis of favipiravir and hydroxychloroquine as FDA-approved drugs for treatment of COVID-19 using synchronous spectrofluorimetry: application to pharmaceutical formulations and biological fluids

Coronavirus disease 2019 (COVID-19) is a contagious viral infection caused by coronavirus 2 (SARS-CoV-2) that causes severe acute respiratory syndrome. It has ravaged several countries and burdened many healthcare systems. As the process of authorizing a novel treatment for human use is extensive and involves multiple phases to obtain safety information and identify potential concerns. Therefore, the fastest and easiest choice was to use United States Food and Drug Administration (US FDA)-approved drugs such as favipiravir and hydroxychloroquine. For the simultaneous estimation of both medications, a simple synchronous spectrofluorimetric approach was established in which both drugs were measured at 372 and 323 nm, respectively in the presence of each other without interference at Δλ 60 nm. The effect of various experimental conditions on synchronous fluorescence intensities were thoroughly investigated and optimized. The maximum synchronous fluorescence intensities were obtained at pH 5.4 using acetate buffer (0.2 M, 0.5 ml) and ethanol as a diluent. Excellent linearity ranges were obtained using 1.0-18.0 ng/ml and 10.0-120.0 ng/ml for favipiravir and hydroxychloroquine, respectively. The approach exhibited high sensitivity with detection limits down to 0.25 ng/ml and 1.52 ng/ml and quantitation limits down to 0.77 ng/ml and 4.62 ng/ml, respectively. Spiking human plasma samples with the studied drugs yielded high % recoveries, allowing a significant bioanalytical application. Moreover, the method was validated according to International Conference on Harmonization guidelines and further applied to commercial pharmaceutical preparations with good results.

Synchronized spectrofluorimetric determination of ponatinib and curcumin as an effective therapeutic combination in laboratory prepared mixtures and human plasma samples

Curcumin is a natural product that is frequently utilized in cancer prevention and treatment. The significant benefit of vegetable-derived nutraceuticals in combination with widespread cytostatic medication such as ponatinib is to reduce toxicity and side effects. In this paper, we focus the study on analytical quantification of ponatinib and curcumin through highly sensitive synchronous spectrofluorometric method. Applying this method at Δλ = 160 nm, each of ponatinib and curcumin could be measured at 303 and 412 nm without interference from each others. The diverse experimental factors impacting the performance of the method were studied and optimized. The method exhibited a reasonable linearity in the ranges of 5.0-60.0 and 10.0-200.0 ng/mL for ponatinib and curcumin, respectively with detection limits of 1.48 and 1.22 ng/mL and quantitation limits of 4.49 and 3.68 ng/mL, respectively. The anticipated method was employed for the assessment and evaluation of the studied drugs in the spiked human plasma samples. The mean % recoveries in plasma samples (n = 6) for each of ponatinib and curcumin were 99.84 ± 1.86 and 100.06 ± 2.72, accordingly. The developed method was validated in conformity with the requirements of International Council of Harmonization (ICH).

Application of different spectrofluorimetric approaches for quantitative determination of acetylsalicylic acid and omeprazole in recently approved pharmaceutical preparation and human plasma

Acetylsalicylic acid and omeprazole were recently formulated by the new FDA-approved drug Yosprala ® Tablets. This novel combination was prescribed to reduce the risk of myocardial infarction in patients who were at risk for developing peptic ulcer while taking acetylsalicylic acid. In the current work, two different high precision sensitive fluorescence spectroscopic methods were developed for quantitative analysis of the above drugs in pharmaceutical dosage form and spiked human plasma. Acetylsalicylic acid was quantitatively analyzed due to its unique native fluorescence nature. The fluorescence emission of acetylsalicylic acid was quantitatively determined at 404 nm after excitation at 296 nm without any interference from omeprazole. Omeprazole, which has a free terminal secondary amino group, reacted with 4-chloro-7-nitrobenzo-2-oxa-1, 3-diazole (NBD-Cl) by a nucleophilic substitution mechanism to form a highly fluorescent dark yellow fluorophore. Omeprazole was quantitatively analyzed by measuring the emission fluorescence intensity of the dark yellow fluorophore at 535 nm after excitation at 465 nm. Various parameters affecting the described methods were carefully checked and optimized. The calibration curves were found to be linear over the concentration range of 50-1600 ng/ml for acetylsalicylic and 30-2000 ng/ml for omeprazole. The proposed methods were successfully applied to the quantitative analysis of the two drugs in the pharmaceutical dosage form Yosprala ® and in spiked human plasma.

A Brief Review of Analytical Methods for the Estimation of Allopurinol in Pharmaceutical Formulation and Biological Matrices

This review article represents the collection and discussion of various analytical methods available in the literature for the determination of allopurinol (ALLP) in pharmaceutical and biological samples consisting of HPLC, UV-visible method, near-IR spectroscopy, spectrofluorometry, capillary electrophoresis, polarography, voltammetry, and hyphenated techniques such as LC-MS, LC-MS/MS, UPLC-MS/MS, and GC-MS. The anticipated review provides details about the comparative utilization of various analytical techniques for the determination of ALLP. The present review article can be effectively explored to conduct future analytical investigation for the estimation of ALLP.