Comparative assessment of saliva and plasma for drug bioavailability and bioequivalence studies in humans

Emergency diagnosis made easy: matrix removal and analyte enrichment from raw saliva using paper-arrow mass spectrometry

Paracetamol overdose is a leading cause of acute liver failure that can prove fatal. Establishing paracetamol concentration accurately and quickly is critical. Current detection methods are invasive, time-consuming and/or expensive. Non-invasive, rapid and cost-effective techniques are urgently required. To address this challenge, a novel approach, called Paper-Arrow Mass Spectrometry (PA-MS) has been developed. This technique combines sample collection, extraction, enrichment, separation and ionisation onto a single paper strip, and the entire analysis process, from sample to result, can be carried out in less than 10 min requiring only 2 μL of raw human saliva. PA-MS achieved a LOQ of 185 ng mL-1, mean recovery of 107 ± 7%, mean accuracy of 11 ± 8% and precision ≤5% using four concentrations, and had excellent linearity (r2 = 0.9988) in the range of 0.2-200 μg mL-1 covering the treatment concentration range, surpassing the best-in-class methods currently available for paracetamol analysis. Furthermore, from a panel of human saliva samples, inter-individual variability was found to be <10% using this approach. This technique represents a promising tool for rapid and accurate emergency diagnosis.

On-Site Therapeutic Drug Monitoring of Paracetamol Analgesic in Non-Invasively Collected Saliva for Personalized Medicine

Paracetamol or acetaminophen is the main non-opioid analgesic recommended for mild pain by the World Health Organization (WHO) analgesic ladder. However, the high levels used of paracetamol are associated with the hepatotoxicity and nephrotoxicity caused by accumulation of toxic metabolites. The sensor is produced on a polyester substrate containing a full electrochemical device with working, auxiliary, and reference electrodes in which, guiding personalized medicine solutions are not reported. Temporal paracetamol profiles in human saliva are performed with the subject taking different amounts of commercial analgesic pills. The variation of saliva paracetamol levels is demonstrated to be interference free from electroactive interfering species and human saliva constituents. In addition, the sensor displays to be useful as a disposable device for the fast detection of paracetamol in untreated raw saliva following pill intake. The maximum concentration (C_max ) and half-life time (t_1/2 ) for paracetamol are 143.27 µm and 110 min. The results demonstrate the potential of a simple strategy with electrochemical devices for noninvasive personalized therapy toward guiding drug interventions through tracking of active substance, detecting, and correcting insufficiency of absorption to meet individual needs avoiding overdoses, side effects, and intoxication.

Pharmacokinetic Basis for Using Saliva Matrine Concentrations as a Clinical Compliance Monitoring in Antitumor B Chemoprevention Trials in Humans

This study reports the first clinical evidence of significantly high secretion of matrine in a multi-component botanical (Antitumor B, ATB) into human saliva from the systemic circulation. This is of high clinical significance as matrine can be used as a monitoring tool during longitudinal clinical studies to overcome the key limitation of poor patient compliance often reported in cancer chemoprevention trials. Both matrine and dictamine were detected in the saliva and plasma samples but only matrine was quantifiable after the oral administration of ATB tablets (2400 mg) in 8 healthy volunteers. A significantly high saliva/plasma ratios for C_max (6.5 ± 2.0) and AUC_0-24 (4.8 ± 2.0) of matrine suggested an active secretion in saliva probably due to entero-salivary recycling as evident from the long half-lives (t_1/2 plasma = 10.0 ± 2.8 h, t_1/2 saliva = 13.4 ± 6.9 h). The correlation between saliva and plasma levels of matrine was established using a population compartmental pharmacokinetic co-model. Moreover, a species-relevant PBPK model was developed to adequately describe the pharmacokinetic profiles of matrine in mouse, rat, and human. In conclusion, matrine saliva concentrations can be used as an excellent marker compound for mechanistic studies of active secretion of drugs from plasma to saliva as well as monitor the patient's compliance to the treatment regimen in upcoming clinical trials of ATB.

Evaluation of rapid and standard tandem mass spectrometric methods to analyse veterinary drugs and their metabolites in antemortem bodily fluids from food animals

Antemortem bodily fluids can serve as an indicator of veterinary medicine exposure prior to food animal slaughter. A multi-residue, rapid screen electrospray ionisation mass spectrometric (RS-ESI-MS) method was developed to analyse 10 veterinary drugs or metabolites (clenbuterol, erythromycin, flunixin, 5-hydroxyflunixin, meloxicam, ractopamine, ractopamine-glucuronide, salbutamol, tylosin, and zilpaterol) in hog oral fluid and bovine urine. Simple acetonitrile extraction with salting-out was employed to remove the analytes from matrices in less than 30 minutes. Instrumental analysis time was < 1 min/injection. Regression coefficients of matrix-matched calibration curves ranged 0.9743-0.9999 across all compounds with limits of detection ranging from 0.46-108 ng mL^-1 for cattle urine and 0.19-64.4 ng mL^-1 for hog oral fluid across all analytes. Except for ractopamine-glucuronide, analyte recoveries ranged from 92.7-106% for oral fluid and urine fortified at 30, 100, and 300 ng mL^-1, with inter-day variations of < 25%. Ractopamine-glucuronide recovery was 93.3% for oral fluid fortified at 300 ng mL^-1. The RS-ESI-MS method accurately identified ractopamine and/or ractopamine-glucuronide in incurred cattle urine with results correlating well with traditional LC-MS/MS and HPLC fluorescence methods. As far as we are aware, this is the first report of the direct quantification of ractopamine-glucuronide from biological matrices without lengthy hydrolysis and cleanup steps.

UHPLC-MS/MS Method for Determination of Hydroxychloroquine and Its Main Metabolites in Oral Fluid and Whole Blood for Therapeutic Drug Monitoring

BACKGROUND

Hydroxychloroquine (HCQ) blood levels are used to monitor efficacy, safety, and patient adherence during treatment. Oral fluid has emerged as an alternative noninvasive, easily accessible, and low-complexity matrix for drug monitoring. However, there is no analytical method to measure HCQ in oral fluid. Therefore, we developed and validated an ultra-high-performance liquid chromatography-tandem mass (UHPLC-MS/MS) method for the measurement of HCQ and its main metabolites in oral fluid and compared to whole blood.

METHODS

Ten microliters of matrices were used for sample preparation by protein precipitation with acetonitrile followed by online solid phase extraction. The validation process included assessment of lower limit of quantification, linearity, precision, recovery, matrix effect, interferences assessment, carryover, and sample dilution validation.

RESULTS

The lower limit of quantification was 50 ng/mL for HCQ and metabolites in both oral fluid and whole blood. The calibration curve was linear from 50 to 2000 ng/mL (r2 = 0.999). The coefficient of variation for precision assay was 1.2% to 9.7% for intraday and 1.1% to 14.2% for interday for both HCQ and metabolites in oral fluid and whole blood samples at 150, 750, and 1250 ng/mL. The recovery was 85.3% to 118.5% for 150, 750, and 1250 ng/mL of HCQ and metabolites in both oral fluid and whole blood. Dilution factor up to 5-fold was validated for concentrations higher than the upper limit of quantification.

CONCLUSIONS

The validated method is specific, precise, and accurate to determine the analytical range for therapeutic monitoring of HCQ and its main metabolites in oral fluid and blood.

Concomitant Drug Treatment and Elimination in the RCC-affected Kidneys: Can We Kill Two Birds with One Stone?

BACKGROUND

The kidneys are vital organs acting as the body's filters that eliminate drugs and other waste products from the body. For effective cancer therapy, a delicate balance is required in the drug treatment and its elimination, which is critical for drug accumulation, toxicity, and kidney malfunction. However, how renal cell carcinoma (RCC) affects the kidneys in safely eliminating the byproducts of drug treatments in patients with severely dysregulated kidney functions had remained elusive. Recent advancements in dose adjustment have added to our understanding regarding how drug treatments could be effectively regulated in aberrant kidney cells, driving safe elimination and reducing drug accumulation and toxicity at the right time and space. Dose adjustment is the only standard systemic way applicable; however, it presents certain limitations. There is significant room for developing new strategies and alternatives to improve it.

OBJECTIVES

Our analysis of the available treatments in literature discusses the treatment and their safe eliminations. In this study, we give an overview of the measures that could be taken to maintain the elimination gradient of anti-cancer drugs and restore normal kidney function in RCC. Differential therapeutics of RCC/mRCC in various clinical phase trials and the interaction of targeted therapeutics in response to vascular endothelial growth factor (VEGF) were also discussed.

CONCLUSION

Such information might suggest a new direction in controlling treatment with safe elimination through dose adjustment and its associated alternatives in a judicious manner. A strategy to systematically focus on the safe elimination of anti-cancer drugs in RCC strongly needs advocating.

Vitamin C, omega-3 and paracetamol pharmacokinetic interactions using saliva specimens as determiners

Background With its low side effects profile and availability as an over-the-counter drug, paracetamol has been utilized extensively worldwide as an antipyretic and analgesic agent for decades. This is associated with the increasing concern over its ease of access and/or unawareness of the consumers to this issue of paracetamol-induced hepatotoxicity. Paracetamol-induced liver injury today is a big problem where most of the researchers are interested in the possible role of the naturally available antioxidants to ameliorate hepatotoxicity through kinetic interference. So the present study was designed to evaluate the effect of vitamin C and omega-3 on the pharmacokinetic property of paracetamol. Methods Six young (average age 29) healthy volunteers participated in the study. The study included three consecutive periods, each of which preceded by overnight fasting and separated by 6 day washout periods. The first period involved the ingestion of a single paracetamol dose. The second one included the ingestion of paracetamol and vitamin C concomitantly, and the final period included paracetamol plus omega-3. Saliva samples were collected and prepared for High-performance liquid chromatography analysis. Results There was a significant increase in saliva paracetamol level after 30 min of administration when given concomitantly with vitamin C compared with the remaining groups. No significant differences in the paracetamol concentration profile between the subjects for each group were observed at 60, 90, 120 and 150 min in all treated groups. Conclusion Concurrent administration of vitamin C with paracetamol increases significantly the Cmax level (maximum measured concentration) in saliva and increases the extent of absorption and the possibility of drug-drug interaction and risk of side effects.