Utility of non-invasive biomatrices in pharmacokinetic studies

Abstract

Blood and plasma are the biomatrices traditionally used for drug monitoring and their pharmacokinetic profiling. Blood is the circulating fluid in contact with all organs and tissues of body and thus, is the most representative fluid for measuring systemic drug levels. However, venipuncture suffers from a single caveat of being an invasive technique which often confers reluctance in minds of people for participating in clinical studies. Thus, there has been a need of using non-invasive bio-fluids that are ethically appropriate, cost-efficient and toxicologically relevant. These alternate bio-fluids may prove clinically useful as alternatives to plasma/serum in Therapeutic drug monitoring, pharmacokinetic and toxicokinetic studies, doping control in sports medicine and to monitor local adverse effects. These may be of particular interest in case of special population groups such as neonates, children, elderly, terminally ill patients and pregnant or lactating women and offers the utmost advantage of circumvention of the demand of specialised personnel for sample collection. The proposed review attempts to describe such non-invasive bio-fluids (saliva, sweat, tears and milk specifically) that have been considered for pharmacokinetic drug analysis, emphasising on their sample preparation, its associated difficulties and their correlation with plasma.