UHPLC-MS/MS method with automated on-line solid phase extraction for the quantification of entecavir in peripheral blood mononuclear cells of HBV+ patients

Green chemistry approach: method development and validation for identification and quantification of entecavir using FT-IR in bulk and pharmaceutical dosage form

Background

Chemical hazard is one of the most prominent side effects that come out along with the benefits of pharmaceutical production. Chemicals usage and waste production are involved in each step of production and are found to be in high percentage at the stage of quality testing. Conventional quality testing (assay) involves the use of solvents and reagents that generates high flammable and non-flammable waste and also enhanced the per batch cost of the medicine, whereas green chemistry offers a benign environment for drug designing, manufacturing, and analysis.

Results

In the present study, a green FTIR method for assay of antiviral drugs entecavir is developed and validated as per ICH Q2_R1 guidelines. A calibration curve is plotted between absorbance and concentration, yielding excellent linearity with a correlation coefficient (r2) value of 0.9991 in the concentration range of 0.25–0.75 mg.

Conclusion

The developed method was validated and was very specific, accurate (99.9–100%) at three levels of 80, 100, and 120% of test concentration and precise with < 1% RSD. The LOD of the method is 0.0674 mg and is able to quantify the active at the limit of 0.2042 mg. Four different drug brands available in the local market are assayed by the validated method, and %recoveries are found to be in the range of 99–101%.

Graphical abstract

Green Chemistry Approach: Method Development and Validation for Identification and Quantification of Entecavir using FT-IR in Bulk and Pharmaceutical Dosage Form

Validation of a UHPLC-MS/MS Method to Quantify Twelve Antiretroviral Drugs within Peripheral Blood Mononuclear Cells from People Living with HIV

Recently, anti-HIV treatment has achieved high efficacy and tolerability. Nevertheless, few data are available about the intracellular penetration of antiretrovirals, partly due to the technical challenges related to intracellular quantification. This work aimed to validate an ultra-high performance liquid chromatography (UHPLC) tandem mass spectrometry (MS/MS) method for the simultaneous quantification of maraviroc, nevirapine, rilpivirine, dolutegravir, raltegravir, cobicistat, darunavir, ritonavir, atazanavir, efavirenz, elvitegravir, and etravirine within peripheral blood mononuclear cells (PBMCs) and apply it to samples from patients. PBMCs were isolated by density gradient on cell preparation tubes (CPT). Samples were prepared by addition of internal standards (IS), sonication, centrifugation, and drying. Reconstituted extracts underwent chromatographic separation by reversed phase UHPLC and detection was performed by electrospray ionization and multiple reaction monitoring. Method validation followed FDA and EMA guidelines, showing acceptable accuracy, precision, recovery and IS-normalized matrix effect. The application to 56 samples from patients undergoing antiretroviral treatment provided description of intracellular penetration, showing method eligibility for future studies.

Low Tenofovir Plasma Exposure in HIV Oral Pre-exposure Prophylaxis Recipients with Gastrointestinal Disorders

Four pre-exposure prophylaxis (PrEP) users with gastro-intestinal disorders (sleeve gastrectomy, terminal ileitis, celiac disease or chronic diarrhea) and receiving oral tenofovir disoproxil fumarate/emtricitabine (TDF/FTC) were included. Despite a self-reported high adherence, trough plasma tenofovir concentrations (after a supervised intake) were significantly lower than those observed in PrEP recipients without gastrointestinal disorders [21 (±9.1) vs. 138 (±85) ng/mL]. PrEP users with gastrointestinal disorders may need increased TDF doses or alternative prophylactic measures.

Development and validation of a UHPLC-MS/MS method for quantification of the prodrug remdesivir and its metabolite GS-441524: a tool for clinical pharmacokinetics of SARS-CoV-2/COVID-19 and Ebola virus disease

Background

Remdesivir has received significant attention for its potential application in the treatment of COVID-19, caused by SARS-CoV-2. Remdesivir has already been tested for Ebola virus disease treatment and found to have activity against SARS and MERS coronaviruses. The remdesivir core contains GS-441524, which interferes with RNA-dependent RNA polymerases alone. In non-human primates, following IV administration, remdesivir is rapidly distributed into PBMCs and converted within 2 h to the active nucleoside triphosphate form, while GS-441524 is detectable in plasma for up to 24 h. Nevertheless, remdesivir pharmacokinetics and pharmacodynamics in humans are still unexplored, highlighting the need for a precise analytical method for remdesivir and GS-441524 quantification.

Objectives

The validation of a reliable UHPLC-MS/MS method for remdesivir and GS-441524 quantification in human plasma.

Methods

Remdesivir and GS-441524 standards and quality controls were prepared in plasma from healthy donors. Sample preparation consisted of protein precipitation, followed by dilution and injection into the QSight 220 UHPLC-MS/MS system. Chromatographic separation was obtained through an Acquity HSS T3 1.8 μm, 2.1 × 50 mm column, with a gradient of water and acetonitrile with 0.05% formic acid. The method was validated using EMA and FDA guidelines.

Results

Analyte stability has been evaluated and described in detail. The method successfully fulfilled the validation process and it was demonstrated that, when possible, sample thermal inactivation could be a good choice in order to improve biosafety.

Conclusions

This method represents a useful tool for studying remdesivir and GS-441524 clinical pharmacokinetics, particularly during the current COVID-19 outbreak.

Correlation between entecavir penetration in peripheral blood mononuclear cells and HBV DNA decay during treatment of HBeAg-negative chronic hepatitis B

BACKGROUND

Recently, due to its high effectiveness and tolerability, the treatment of chronic hepatitis B with entecavir became a standard practice. However, limited knowledge is currently available about its pharmacokinetic behaviour and intracellular disposition. Recently, our group reported an inverse correlation between entecavir plasma concentrations and the HBV DNA decay at the first and third month of treatment, respectively. In this paper we investigated the penetration of entecavir in peripheral blood mononuclear cells (PBMC) and in plasma, in order to evaluate the relationship between intracellular penetration and response, in a cohort of naive patients with hepatitis B e antigen (HBeAg)-negative CHB.

METHODS

Thirty-three patients were prospectively enrolled and gave written informed consent: the monitoring of clinical parameters (for example, HBV DNA, hepatitis B surface antigen [HBsAg], alanine aminotransferase) was carried out at the baseline and then monthly. Entecavir intra-PBMC and plasma trough concentrations were measured at 1 month of treatment, through a validated method based on liquid chromatography coupled with tandem mass spectrometry.

RESULTS

While plasma entecavir analysis confirmed previous evidence of inverse correlation between drug concentrations and HBV DNA decrease after 3 months of treatment (r=-0.723; P<0.001), this correlation was not significant for intra-PBMC concentrations. When the intracellular disposition ratio (intra-PBMC/plasma concentration ratio) was considered, it showed a direct and significant correlation with HBV DNA decay at the third month (r=0.485; P=0.004).

CONCLUSIONS

These results suggest that the antiviral activity of entecavir is dependent on its intracellular uptake, thus resulting in lower plasma concentrations in patients who have a marked HBV DNA decrease during treatment.

Correlation Between Serum Entecavir Concentration and Virological Response in Patients with Chronic Type B Hepatitis

Background

This study was conducted to investigate the relationship between trough concentrations of serum entecavir and the virological response of patients with chronic type B hepatitis (CHB).

Material/Methods

A total of 59 CHB patients who had been receiving antiviral therapy with entecavir for >3 months were included in this study. Serum entecavir concentrations, HBV DNA levels, and other biochemical indicators were determined after drug treatments.

Results

The serum entecavir concentrations in the good response and poor response groups were 0.58±0.38 and 0.43±0.15 ng/mL, respectively. The antiviral efficacy was 52.38%, 65.63%, and 100% in low, middle, and high entecavir groups, respectively. The baseline HBV DNA level among the patients with poor response was significantly higher than in the group with good response. Among the 14 patients with a high viral load, 5 patients showed a good response and had a higher entecavir concentration than the other 9 patients with poor response. Entecavir in patients with cirrhosis was higher than in those without cirrhosis (0.63±0.45 ng/mL vs. 0.46±0.16 ng/mL), and the virological response rate in patients with cirrhosis was higher than in those without cirrhosis (83.33 vs. 51.43%). Cirrhosis progression was reversed in 3 patients with high serum entecavir concentration.

Conclusions

Serum entecavir concentrations vary among individuals, and higher serum entecavir concentration is correlated with more efficient viral clearance. Therefore, for patients with poor response, high doses may be beneficial for viral clearance.

Advances in biomarker detection: Alternative approaches for blood-based biomarker detection

In the clinical setting, a blood sample is typically the starting point for biomarker search and discovery. Mass spectrometry (MS) is a highly sensitive and informative method for characterizing a very wide range of metabolites and proteins and is therefore a potentially powerful tool for biomarker discovery. However, the physicochemical characteristics of blood coupled with very large ranges of protein and metabolite concentrations present a significant technical obstacle for resolving and quantifying putative biomarkers by MS. Blood fractionation procedures are being developed to reduce the proteome/metabolome complexity and concentration ranges, allowing a greater diversity of analytes, including those at very low concentrations, to be quantified. In this chapter, several strategies for enriching and/or isolating specific blood components are summarized, including methods for the analysis of low and high molecular weight compounds, usually neglected in this type of assays, extracellular vesicles, and peripheral blood mononuclear cells (PBMCs). For each method, relevant practical information is presented for effective implementation.

Recent advances of online coupling of sample preparation techniques with ultra high performance liquid chromatography and supercritical fluid chromatography

Ultra high performance liquid chromatography and supercritical fluid chromatography techniques are favored because of their high efficiency and fast analysis speed. Although many sample preparation techniques have been coupled with common liquid chromatography online, the online coupling of sample preparation with the two popular chromatography techniques have gained increasing attention owing to the increasing requirements of efficiency and sensitivity. In this review, we have discussed and summarized the recent advances of the online coupling of sample preparation with ultra high performance liquid chromatography and supercritical fluid chromatography techniques. The main sample preparation techniques that have been coupled with ultra high performance liquid chromatography online are solid-phase extraction and in-tube solid-phase microextraction, while solid-phase extraction and supercritical fluid extraction are the main techniques that have been coupled with supercritical fluid chromatography online. Especially, the strategies for online coupling of sample preparation with chromatography techniques were summarized. Typical applications and growing trends of the online coupling techniques were also discussed in detail. With the increasing demands of improving the efficiency, throughput, and analytical capability toward complex samples of the analysis methods, online coupling of sample preparation with chromatography techniques will acquire further development.

Liver-Targeted Co-delivery of Entecavir and Glycyrrhetinic Acid Based on Albumin Nanoparticle To Enhance the Accumulation of Entecavir

Hepatitis B, one of the most common contagious viral hepatitis with high infection rate, is challenging to treat. Although the treatment for hepatitis B has been improved over the years, many therapeutic drugs still have either severe adverse effects or insufficient effectiveness via systemic administration. In this study, we confirmed that glycyrrhetinic acid can enhance the accumulation of entecavir in HepaRG cell and liver. Then we constructed a novel albumin nanoparticle co-loading entecavir and glycyrrhetinic acid (ETV-GA-AN) to improve liver accumulation of entecavir and investigated its ability to deliver both drugs to liver. In vitro cellular uptake study and in vivo tissue distribution experiment showed that these negatively charged ETV-GA-AN (112 ± 2 nm in diameter) can increase the accumulation of entecavir in hepatic HepaRG cells and improve entecavir distribution in liver. We also revealed the mechanism that glycyrrhetinic acid enhances intracellular accumulation of entecavir by inhibiting the activity of specific efflux transporters. Our delivery system is the first liver-targeted albumin nanoparticle that utilizes the site-specific co-delivery strategy to delivery entecavir and glycyrrhetinic acid. As it combines high efficiency and low toxicity, it possess great potential for treating hepatitis B.

Matrix effect management in liquid chromatography mass spectrometry: the internal standard normalized matrix effect

LC-MS is becoming a standard for many applications, thanks to high sensitivity and selectivity; nevertheless, some issues are still present, particularly due to matrix effect (ME). Considering this, the use of optimal internal standards (ISs, usually stable-isotope labeled) is important, but not always possible because of cost or availability. Therefore, a deep investigation of the inter-lot variability of the ME and of the correcting power of the chosen IS (isotope-labeled or not) is mandatory. While the adoption of isotopically labeled ISs considered as a 'gold standard' to mitigate ME impact on analytical results, there is not consensus about the standard technique to evaluate it during method validation. In this paper, currently available techniques to evaluate, reduce or counterbalance ME are presented and discussed. Finally, these techniques were summarized in a flowchart for a robust management of ME, particularly considering the concept of 'internal standard normalized ME'.

Current antiviral drugs and their analysis in biological materials - Part II: Antivirals against hepatitis and HIV viruses

This review is a Part II of the series aiming to provide comprehensive overview of currently used antiviral drugs and to show modern approaches to their analysis. While in the Part I antivirals against herpes viruses and antivirals against respiratory viruses were addressed, this part concerns antivirals against hepatitis viruses (B and C) and human immunodeficiency virus (HIV). Many novel antivirals against hepatitis C virus (HCV) and HIV have been introduced into the clinical practice over the last decade. The recent broadening portfolio of these groups of antivirals is reflected in increasing number of developed analytical methods required to meet the needs of clinical terrain. Part II summarizes the mechanisms of action of antivirals against hepatitis B virus (HBV), HCV, and HIV, their use in clinical practice, and analytical methods for individual classes. It also provides expert opinion on state of art in the field of bioanalysis of these drugs. Analytical methods reflect novelty of these chemical structures and use by far the most current approaches, such as simple and high-throughput sample preparation and fast separation, often by means of UHPLC-MS/MS. Proper method validation based on requirements of bioanalytical guidelines is an inherent part of the developed methods.

First UHPLC-MS/MS method coupled with automated online SPE for quantification both of tacrolimus and everolimus in peripheral blood mononuclear cells and its application on samples from co-treated pediatric patients

Tacrolimus (TAC, FK-506) and everolimus (EVE, RAD001) are immunosuppressors used to treat pediatric patients undergoing liver transplantation. Their hematic TDM by liquid chromatography became standard practice. However, it does not always reflect concentrations at their active site. Our aim was to develop and validate a new method for the simultaneous TAC and EVE quantification into target cells: peripheral blood mononuclear cells (PBMCs). Peripheral blood mononuclear cells were collected using cell preparation tubes; cells number and mean cell volume were evaluated by an automatic cell counter. TAC and EVE were quantified using UHPLC-MS/MS coupled with an automated online solid-phase extraction platform. Chromatographic run was performed on an Acquity UPLC® BEH C18 1.7 μm (2.1 × 50 mm) column at 45 °C, for 6 min at 0.5 ml/min. Mobile phases were water and methanol, both with 2 mm ammonium acetate and 1 ml/l formic acid). XBridge® C8 10 μm (1 × 10 mm) SPE cartridges were used, and the internal standard was ascomycin. Following Food and Drug Administration guidelines, method validation resulted in high sensitivity and specificity. Calibration curves were linear (r²  = 0.998) and intra-day and inter-day imprecision and inaccuracy were <15%. A reproducible matrix effect was observed, with a good recovery for all compounds. Drug amounts in 15 'real' PBMCs samples from five pediatric patients in co-treatment resulted within the calibration range (0.039-5 ng). Concentrations from each patient were standardized using their evaluated mean cell volume: intra-PBMCs concentration was meanly 19.23 and 218.61 times higher than the hematic one for TAC and EVE, respectively. This method might be useful in clinical routine, giving reliable data on drugs concentration at the active site. Copyright © 2017 John Wiley & Sons, Ltd.

Entecavir plasma concentrations are inversely related to HBV-DNA decrease in a cohort of treatment-naïve patients with chronic hepatitis B

The role of therapeutic drug monitoring (TDM) of entecavir (ETV) in the treatment of patients affected by chronic hepatitis B (CHB) has not yet been defined. Here we present an interim analysis regarding the role of ETV TDM in a prospective cohort of treatment-naïve patients with CHB who received this treatment. The results from 40 patients consecutively enrolled at our centre from 2010 to 2013 are described. The primary endpoint was the evaluation of the role of ETV plasma concentrations in the kinetics of hepatitis B virus (HBV) DNA decrease. Minimum ETV concentrations (Ctrough) were measured every month after the start of therapy for the first 3 months and then every 6 months. The main result of the pharmacokinetic analysis was the significant inverse correlation of ETV concentration after 1 month of treatment and HBV-DNA decrease after 3 months of treatment (r = -0.624; P <0.001). This correlation was also confirmed when stratifying patients on the basis of viral genotypes: A (r = -0.719; P = 0.003); C (r = -0.917; P = 0.007); and D (r = -0.760; P = 0.007). Possible explanations for this phenomenon could involve interpatient differences in liver conditions (tissue damage or inflammation) and/or genetic variability in specific drug transporters. Further investigations are needed to confirm these results quantifying ETV concentration in peripheral blood mononuclear cells as well as in a larger cohort.