Humans are composed primarily of water, which means that our cells are accustomed to functioning in aqueous environments. As a result, the water in cellular media or in vitro environments can substantially impact how cells behave. When testing a drug candidate with the goal of reaching clinical trials, it’s important to use only pure, uncontaminated water.
Water in animal models
Animal models are often used to provide proof of effect and justify clinical trials in humans. However, animal model testing is expensive to conduct, which makes unnecessary waste difficult to justify. For these experiments, the gold standard is sterile water handled exclusively in a biosafety cabinet to prevent contamination of any kind. This minimizes the likelihood of confounding results that can stem from contaminants that introduce disease (such as bacteria), or poison the animal, potentially altering disease progression and survival.
Water in cell models
The hydration of an environment can alter a cell’s vibrations, conformations, protein structure, and transition state. Water that is contaminated or in short supply may affect the outcome of downstream experiments by changing the way the cells react to a drug, a pathogen, or any other experimental construct. At that point, it’s difficult to determine which effects can be attributed to the disease or treatment and which are a result of contamination. To ensure that you can fully explain your results, using high-grade water in your cell experiments is a must.
Clinical trials: The purity of water can dictate the future of the drug
Water quality is no less important for humans than for cells or animals. In a clinical trial, it is important to ensure that humans are not being treated with contaminated water for not only their health and safety, but also the outcome of the clinical trial.
There is another caveat to clinical trials, however. Following treatments given as part of a clinical trial, participants are typically expected to provide blood or urine samples for follow-up. The techniques used to analyze these samples can include HPLC, ion chromatography, immunoassays, and others, all of which require high-quality water—so purity is required from start to finish, whether establishing baselines or conducting follow-up tests.