Where Does Poor DMSO Solubility Come From

Where Does Poor DMSO Solubility Come From  

Precipitation of compound from a DMSO stock is an issue of compound solubility in DMSO [14]. However, operationally, most organizations dissolving compounds in DMSO do not encounter problems in the solubilization process. This apparent paradox is explained by the issue of amorphous compounds. The vast majority of compounds solubilized into DMSO stocks are amorphous and inherently more soluble in DMSO (as previously discussed). The vast majority of the same compounds precipitating from DMSO are crystalline and much less soluble in DMSO (as previously discussed). The problem of compounds precipitating from DMSO occurs because so many compounds entering into screening libraries are amorphous. The precipitation of compounds from DMSO would be far less of a problem if screening compounds were entirely crystalline as they were 20 years ago. Quite simply DMSO insoluble crystalline compounds would never have been successfully dissolved in DMSO in the first place. 

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