Screening for salts or co-crystals

In the early phase of drug development, a decision has to be made whether or not the uncharged molecule is adequate as a drug substance. If it is unsuitable due to e.g. low solubility, chemical stability or melting point, other options such as salts or co-crystals must be considered. At Solvias, we believe that your optimal salt / co-crystal can be chosen quickly based on the factors above and also its hygroscopicity, crystallinity, and suitability for production.

Using a well-designed screening process, we typically start by screening a large number of potential acids, bases or co-crystal formers in a robotic high-throughput format in order to quickly find leads, which are then scaled-up and further characterized. In this way the optimal salt / co-crystal can be identified quickly.

Toxicological aspects, as defined by FDA GRAS (generally recognised as safe) criteria, and the intended application influence which possible counter ions or co-crystal formers are selected for the screen.