In vitro stability of triclosan in dentifrice under simulated use condition

Evaluation of multiple hydrophilic interaction chromatography columns and surrogate matrix for arginine quantification in saliva by high-resolution mass spectrometry

Arginine, a pivotal ingredient in many biochemical synthetic pathways, can be used as a biomarker for many oral care clinical applications. It is still a challenge to develop a sensitive and reliable chromatographic method to quantify arginine as a biomarker in saliva, with or without arginine product pretreatment. The current method solved two critical issues for arginine quantitation in human saliva. The first issue was how to optimize arginine peak shape. A hydrophilic interaction chromatography method based on the column selection, pH and pK_a relationship, mobile phase ionic strength, organic solvent consideration, and temperature effects was developed. An optimized chromatographic condition for arginine quantitation in the saliva matrix was obtained. The second issue was how to build confidence in the use of a simple surrogate matrix methodology to replace the more complex traditional standard addition methodology. The surrogate matrix methodology we developed is applicable to the measurement of arginine as a potential non-invasive biomarker in human saliva. The method detection and quantification limit reached 2 and 6 ng/mL. The tailing factor was within the 0.9-1.1 range even though arginine had three pK_a values at 2.18, 9.09, and 13.2.

Persistence, ecological risks, and oxidoreductases-assisted biocatalytic removal of triclosan from the aquatic environment

Triclosan (TCS) has been immensely employed in health care products and consumer items, as an active agent with fungicidal and bactericidal potentialities, such as soaps, sanitizers, tubes of toothpaste, deodorants, skin creams, and so on for over last five decades. The ultimate excretory route of TCS ends in our water matrices, thus has been frequently detected with ecological and human-health related matters and hazards. Bioactive residues of TCS reach into the key atmosphere compartment through numerous routes, such as (1) scarce or ineffective elimination or degradation throughout the treatment practices, (2) abandoned landfill leachates, (3) leakage from the discarded TCS-containing materials, and so on. Such persistence and occurrence of TCS or its degraded but bioactive residues have growing attentions. Its complete removal and/or effective prevention are still challenging tasks for safeguarding the environment. Owing to the highly effective catalytic and stability potential, enzyme-based bio-degradation approaches are considered an evocative substitute for TCS mitigation from environmental matrices. As compared to enzymes in their pristine form, immobilized enzymes, with unique catalytic, stability, selectivity, and reusability profile, are of supreme and strategic interest in environmental biotechnology. Herein, an effort has been made to signify the novel bio-catalytic and bio-degradation potentialities of various oxidoreductases, including laccases, and peroxidases including soybean peroxidase, versatile manganese peroxidase, and horseradish peroxidase with suitable examples. Following a brief introduction, the focus is given to the presence of TCS in the key atmosphere compartments. Potential sources, acquaintance, and hazardous influence of TCS are also discussed with recent and relevant examples. The second half shows the TCS removal/degradation potentialities of soluble enzyme-based catalytic systems and immobilized-enzyme-based catalytic systems. Finally, the concluding remarks, along with possible future directions are given in this significant research arena.

Triclosan: A review on systematic risk assessment and control from the perspective of substance flow analysis

Triclosan (TCS) is a broad spectrum antibacterial agent mainly used in Pharmaceutical and Personal Care Products. Its increasing use over recent decades have raised its concentration in the environment, with commonly detectable levels found along the food web-from aquatic organisms to humans in the ecosystem. To date, there is shortage of information on how to investigate TCS's systematic risk on exposed organisms including humans, due to the paucity of systematic information on TCS flows in the anthroposphere. Therefore, a more holistic approach to mass flow balancing is required, such that the systematic risk of TCS in all environmental matrices are evaluated. From the perspective of Substance Flow Analysis (SFA), this review critically summarizes the current state of knowledge on TCS production, consumption, discharge, occurrence in built and natural environments, its exposure and metabolism in humans, and also the negative effects of TCS on biota and humans. Recent risk concerns have mainly focused on TCS removal efficiencies and metabolism, but less attention is given to the effect of mass flows from source to fate during risk exposure. However, available data for TCS SFA is limited but SFA can derive logical systematic information from limited data currently available for systematic risk assessment and reduction, based on mass flow analysis. In other words, SFA tool can be used to develop a comprehensive flow chart and indicator system for the risk assessment and reduction of TCS flows in the anthroposphere, thereby bridging knowledge gaps to streamline uncertainties related to policy-making on exposure pathways within TCS flow-lines. In the final analysis, specifics on systematic TCS risk assessment via SFA, and areas of improvement on human adaptation to risks posed by emerging contaminants are identified and directions for future research are suggested.

Triclosan: current status, occurrence, environmental risks and bioaccumulation potential

Triclosan (TCS) is a multi-purpose antimicrobial agent used as a common ingredient in everyday household personal care and consumer products. The expanded use of TCS provides a number of pathways for the compound to enter the environment and it has been detected in sewage treatment plant effluents; surface; ground and drinking water. The physico-chemical properties indicate the bioaccumulation and persistence potential of TCS in the environment. Hence, there is an increasing concern about the presence of TCS in the environment and its potential negative effects on human and animal health. Nevertheless, scarce monitoring data could be one reason for not prioritizing TCS as emerging contaminant. Conventional water and wastewater treatment processes are unable to completely remove the TCS and even form toxic intermediates. Considering the worldwide application of personal care products containing TCS and inefficient removal and its toxic effects on aquatic organisms, the compound should be considered on the priority list of emerging contaminants and its utilization in all products should be regulated.