Mitsuhiko Kawabata is team leader of the pharmacokinetics group at Shin Nippon Biomedical. He explains:
"There are three main techniques for extracting samples - protein precipitation, liquid-liquid extraction, and solid phase extraction. Liquid-liquid extraction is falling from favor because it is cumbersome and involves a large amount of liquid. However, solid phase extraction requires many treatment steps, is cumbersome, and takes a long time, while protein precipitation, though fast, does not yield clean samples. In this sense, ISOLUTE SLE+ is an excellent option - it allows us to perform liquid-liquid extractions that yield cleaner samples and require less labor."
"It is quite simple to use. With ISOLUTE SLE+, it is only a two-step process of sample application followed by a short wait and then elution. It's really quite hassle-free, which is an enormous advantage. We had the impression that more preparation steps result in cleaner samples, So it was something of a surprise that we were able to obtain clean samples with such a simple method."
"When selecting ISOLUTE SLE+, one of our concerns was that there might be variation between lots. However, this concern turned out to be unfounded. Diatomaceous earth is simply a support for liquid-liquid partitioning, so it would not be an element that could cause a lot-to-lot difference."
Colleague Akiko Toda fills in:
"In preparing samples using liquid-liquid extraction, some of the compounds may collect in the organic solvent and water emulsion mixture, giving rise to variance in the results. With ISOLUTE SLE+, this problem does not occur. This is another reason why the analysis results have higher reproducibility."
"ISOLUTE SLE+ can be used with a sample volume as small as 200 μL. It also allows our work to be carried out very efficiently. As far as we knew, Biotage was the only manufacturer that offered a product that could satisfy this kind of need. When we use ISOLUTE SLE+, we feel the target can be extracted more efficiently and with less effort."
"Drug development takes many years, so once a method has been established, it will remain in use, sometimes as long as five or even ten years. This means that securing a stable supply that we could count on for a long time was a concern for us."
"With earlier liquid-liquid extraction, we would avoid the use of a solvent with a higher specific gravity. With SLE+ we are able to use dichloromethane. Among other things, this enables us to work with solvents we had seldom used before, so we have more trials to do."
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