A Review on Analytical Strategies for the Assessment of Recently Approved Direct Acting Antiviral Drugs

Determination of anti-SARS-CoV-2 virustatic pharmaceuticals in the aquatic environment using high-performance liquid chromatography high-resolution mass spectrometry

The Covid-19 pandemic has affected the global population since 2019. The rapid development and approval of vaccines has brought relief. Yet, effective cures are still being researched. Even if the pandemic situation may end, SARS-CoV-2 will remain and, thus, continued application of the drugs will lead to emissions of the active ingredients into the aquatic environment, as with other anthropogenic micropollutants. However, a general method for trace analysis of antiviral drugs is still missing. To this purpose, favipiravir, remdesivir, its active metabolite GS-441524, molnupiravir and its active metabolite EIDD-1931 were selected as representative analytes. A method was developed based on solid phase extraction and high-performance liquid chromatography combined with electrospray ionization quadrupole time-of-flight high-resolution mass spectrometry. Optimization comprised the choice of chromatographic columns, elution gradient, mass spectrometry and tandem mass spectrometry parameters. Solid phase extraction proved suitable for increase in limits of detection and quantitation. amelioration of the limits of detection and quantitation. Matrix effects were investigated applying the optimized method to a wastewater sample with added virustatics. All five compounds could be separated with reversed phase chromatography, whereas EIDD-1931 profited from hydrophilic interaction liquid chromatography. The optimized method yielded limits of detection and quantification of 2.1·10-1, 6.9·10-1 µg·L-1 for favipiravir, 1.8·10-3, 5.5·10-3 µg·L-1 for remdesivir, 1.9·10-3, 7.6·10-3 µg·L-1 for GS-441524, 2.9·10-3, 8.7·10-3 µg·L-1 for molnupiravir, and 1.3·10-1, 3.8·10-1 µg·L-1 for EIDD 1931. The method was first applied to compound stability testing at pH 2.8 and 9.7. At pH 2.8, remdesivir, GS-441524 and molnupiravir proved stable, whereas about 14% of EIDD-1931 and favipiravir were degraded. All five antiviral compounds were almost completely decomposed at pH 9.7. The application of the method was further demonstrated for potential transformation product detection on favipiravir ozonation monitoring.

Mathematical processing of absorption as green smart spectrophotometric methods for concurrent assay of hepatitis C antiviral drugs, Sofosbuvir and Simeprevir: application to combined pharmaceutical dosage forms and evaluation of the method greenness

The present work was developed to create three rapid, simple, eco-friendly, cheap spectrophotometric methods for concurrent assay of Sofosbuvir (SOF) and Simeprevir (SMV) in their pure, laboratory prepared mixture and pharmaceutical dosage form with high degree of accuracy and precision. Three methods were developed including iso-absorptive point, ratio subtraction and dual wavelength. The linear range of the proposed methods was 3.0-50.0 and 2.0-50.0 µg mL^-1 for SMV and SOF, respectively. The proposed methods were validated according to ICH guidelines in terms of linearity, accuracy, precision, limit of detection and limit of quantitation. The proposed approach is highly simple and the procedure is environmentally green making it suitable for the drug analysis in routine works.

Analytical Methodologies for the Estimation of Oxazolidinone Antibiotics as Key Members of anti-MRSA Arsenal: A Decade in Review

Gram-positive bacterial infections are among the most serious diseases related with high mortality rates and huge healthcare costs especially with the rise of antibiotic-resistant strains that limits treatment options. Thus, development of new antibiotics combating these multi-drug resistant bacteria is crucial. Oxazolidinone antibiotics are the only totally synthetic group of antibiotics that showed activity against multi-drug resistant Gram positive bacteria including MRSA because of their unique mechanism of action in targeting protein synthesis. This group include approved marketed members (tedizolid, linezolid and contezolid) or those under development (delpazlolid, radezolid and sutezolid). Due to the significant impact of this class, larger number of analytical methods were required to meet the needs of both clinical and industrial studies. Analyzing these drugs either alone or with other antimicrobial agents commonly used in ICU, in the presence of pharmaceutical or endogenous biological interferences, or in the presence of matrix impurities as metabolites and degradation products poses a big analytical challenge. This review highlights current analytical approaches published in the last decade (2012-2022) that dealt with the determination of these drugs in different matrices and discusses their advantages and disadvantages. Various techniques have been described for their determination including chromatographic, spectroscopic, capillary electrophoretic and electroanalytical methods. The review comprises six sections (one for each drug) with their related tables that depict critical figures of merit and some experimental conditions for the reviewed methods. Furthermore, future perspectives about the analytical methodologies that can be developed in the near future for determination of these drugs are suggested.

In-depth investigation of the Silymarin effect on the pharmacokinetic parameters of sofosbuvir, GS-331007 and ledipasvir in rat plasma using LC-MS

The use of complementary medicine (CMD) for liver support in Hepatitis C virus (HCV) patients sometimes coincides with the administration of oral antiviral drugs to eradicate the virus. This calls for a deep investigation of CMD effects on the pharmacokinetic parameters of these drugs to ensure their safety and efficacy. Silymarin (SLY), as a CMD, was selected to be given orally to healthy male rats with sofosbuvir (SFB) and ledipasvir (LED), a common regimen in HCV treatment. A new and sensitive LC-MS method was validated for the bioassay of SLY, LED, SFB and its inactive metabolite, GS-331007, in spiked plasma with lower limits of quantitation of 10, 1, 4 and 10 ng/ml, respectively. Moreover, the method was further applied to conduct a full pharmacokinetic profile of SFB, GS-331007 and ledipasvir with and without SLY. It was found that co-administration of SLY may expose the patient to unplanned high serum concentrations of SFB and LED. This could be accompanied by a decrease in SFB efficacy, potentially leading to therapeutic failure and the emergence of viral resistance.