Quantitative analysis of two COVID-19 antiviral agents, favipiravir and remdesivir, in spiked human plasma using spectrophotometric methods; greenness evaluation

Ecofriendly spectrophotometric methods for simultaneous determination of remdesivir and moxifloxacin hydrochloride as co administered drugs in corona virus treatment

Remdesivir and moxifloxacin hydrochloride are among the most frequently co-administered drugs used for COVID-19 treatment. The current work aims to evaluate green spectrophotometric methodologies for estimating remdesivir and moxifloxacin hydrochloride in different matrices for the first time. The proposed approaches were absorbance subtraction, extended ratio subtraction and amplitude modulation methods. In order to determine the absorbance of the investigated medications in combination at the isoabsorptive point, the pure moxifloxacin hydrochloride absorbance factor is applied using the absorbance subtraction method, which modifies the zero absorption spectra of the drugs under investigation at the isoabsorptive point (229 nm). The spectrum of moxifloxacin hydrochloride is more extended in the plateau area between 340 and 400 nm, where remdesivir exhibits no absorption. So, also, the ratio spectra were successfully manipulated for quantification of the two drugs. Regarding the pharmacokinetic profile of remdesivir (Cmax 4420 ng/mL) and moxifloxacin hydrochloride (Cmax 3.56 µg/mL), the proposed methods were effectively used to spectrophotometrically determine remdesivir and moxifloxacin hydrochloride in plasma matrix. The new approach was validated using the ICH guidelines for specificity, linearity, precision, and accuracy. The greenness of the reported methodologies was evaluated using two metrics: the analytical eco-scale and the green analytical procedure index.

A newly developed high-performance thin layer chromatographic method for determination of remdesivir, favipiravir and dexamethasone, in spiked human plasma: comparison with the published methods

Co-administration of COVID-19 RNA polymerase inhibitors, remdesivir and favipiravir, has synergistic benefits. Together they reduce viral load and inflammation more effectively than either drug used alone. Corticosteroids like dexamethasone are used alongside antivirals in multidrug combination regimens. A new HPTLC method was utilized to isolate and quantitatively determine the three medicines of the COVID-19 therapeutic protocol, remdesivir, favipiravir and dexamethasone, using the anticoagulant apixaban as an internal standard in human plasma. The mobile phase system used a solvent mixture of ethyl acetate, hexane, and acetic acid (9:1:0.3, by volume). At 254 nm, well-resolved spots with Rf values of 0.3 for remdesivir, 0.64 for dexamethasone, and 0.77 for favipiravir have been observed. To ensure compliance with FDA regulations, a validation study was conducted. Quantitation limits as low as 0.1 µg/band have been achieved with remdesivir and dexamethasone, and 0.2 µg/band with favipiravir, demonstrating excellent sensitivities. From 97.07% to 102.77%, the drugs were recovered from human plasma that had been artificially spiked. The whiteness of the method has been assessed using RGB 12 algorithm and a percentage of whiteness of 95.6% has been obtained.

Three spectrophotometric quantitative analysis of bisoprolol fumarate and telmisartan in fixed-dose combination utilizing ratio spectra manipulation methods

Hypertension is a chronic condition with multiple drug regimens. Limiting these medicines is critical to patient compliance. Therefore, bisoprolol and telmisartan were recently developed in a fixed-dose combination to control blood pressure. The UV absorption spectra of bisoprolol and telmisartan overlapped significantly. Thus, three spectrophotometric methods have been developed for simultaneous determination of bisoprolol and telmisartan without prior separation. Method A is ratio difference of ratio spectra (RD), which measures the amplitude difference between (210-224) nm for bisoprolol and between (255-365) nm for telmisartan. Method B, the first derivative of ratio spectra (1DD), measures amplitude signals at 232 and 243 nm for bisoprolol and telmisartan, respectively. Method C is the mean centering of ratio spectra (MC), which measures the mean-centered ratio spectra's values at 223 nm for bisoprolol and 245 nm for telmisartan. The applied methods showed good linearity 2-20 µg/mL for bisoprolol, 4-32 µg/mL for telmisartan, with sufficient accuracy and precision. The methods were sensitive, with LOD values of 0.243 µg/mL and 0.596 µg/mL in RD method, 0.313 µg/mL and 0.914 µg/mL in 1DD method, and 0.406 and 0.707 µg/mL in MC method for bisoprolol and telmisartan, respectively, the methods were validated per ICH criteria. The novel methods are precise and accurate and can be used for routine analysis and quality control of bisoprolol and telmisartan in pure and dosage form. Furthermore, the greenness of the approaches was evaluated using Analytical Greenness assessment (AGREE), and the suggested method received a high greenness score.

Application of signal processing techniques for the spectroscopic analysis of dolutegravir and lamivudine: a comparative assessment and greenness appraisal

HIV treatment has greatly improved over the years, with the introduction of antiretroviral drugs that target the virus and suppress its replication. Dolutegravir and lamivudine are two such antiretroviral drugs that are commonly used in HIV treatment regimens. Herein, three spectrophotometric methods manipulating ratio spectra were developed for the simultaneous analysis of dolutegravir and lamivudine in their binary mixtures. These methods include mathematical processing stages like ratio difference method or signal processing approaches such as the first derivative of the ratio spectra, and continuous wavelet transform. The developed spectrophotometric methods exploit the characteristic spectral differences between dolutegravir and lamivudine in order to quantify them simultaneously. These methods have shown promising results in terms of sensitivity and selectivity as validated per the ICH guidelines. Moreover, these methods offer a straightforward and economical alternative to more intricate analytical methodologies like high-performance liquid chromatography. By incorporating the analytical eco-scale and AGREE for greenness evaluation of the proposed methods, we can further ensure that these techniques are effective and environmentally friendly, aligning with the principles of green chemistry. This evaluation will provide a comprehensive understanding of the environmental friendliness of these spectrophotometric methods in pharmaceutical analysis.

Utilization of absorbance subtraction and ratio difference green spectrophotometric methods for the quantification of alfuzosin hydrochloride and tadalafil in their binary mixture

Alfuzosin hydrochloride and tadalafil fixed-dose combination tablets were recently formulated for the treatment of individuals with lower urinary tract symptoms caused by benign prostatic hyperplasia. Herein, the first spectrophotometric methods for quantitative analysis of alfuzosin hydrochloride and tadalafil in their binary mixture were established. The spectral overlapping of alfuzosin hydrochloride and tadalafil made direct simultaneous analysis unfeasible. Therefore, two mathematical methods were used to solve these overlapping spectra: absorbance subtraction and ratio difference. The absorbance subtraction method manipulates the zero absorption spectra of the studied drugs at the isoabsorptive point (272 nm) and uses the absorbance factor of pure ALF to calculate the absorbance of the studied drugs in the mixture at the isoabsorptive point. The ratio spectra method, on the other hand, manipulates the ratio spectra of the studied drugs, which are obtained by dividing each drug's zero absorption spectra by a divisor spectrum from the second drug. The ratio amplitude difference between 251 nm and 211 nm was directly proportional to alfuzosin hydrochloride, whereas between 292 nm and 222 nm it was directly proportional to tadalafil. The methods used were verified in accordance with the recommendations of the ICH and demonstrated adequate linear regression in working ranges of 1-15 µg/mL for alfuzosin hydrochloride and 3-40 µg/mL for tadalafil. The methods were accurate, precise, and selectively employed to quantify alfuzosin hydrochloride and tadalafil in their combined tablets.

An eco-friendly one-pot spectrofluorimetric approach for the facile determination of overactive bladder drug, tolterodine: Application to dosage forms and biological fluids

Tolterodine tartrate (TTD) was the first antimuscarinic medication developed exclusively for the treatment of overactive bladder syndrome and was approved by the FDA in 1998. As a result of the drug's extensive utilization within the local community following its authorization, there is a pressing need to develop and validate a spectrofluorometric method that is economically efficient, easily reproducible, environmentally sustainable, and possesses high sensitivity. The developed approach relies on enhancing the fluorescence intensity of TTD to reach a level 720 % higher than its initial value, achieved through the application of an aqueous sodium dodecyl sulfate (SDS) solution. A strong correlation was observed with a correlation coefficient of 0.9998 between the concentration of TTD and the fluorescence intensity within the range of 25.0-500.0 ng mL-1. This approach could be employed to quantify TTD in its pure form and to examine pharmaceutical tablets for the purposes of verifying uniform content. Additionally, it was utilized for the evaluation of TTD concentrations in spiked human plasma.