Driven by the requirement for completely dry samples, pharmaceutical compound handling groups are increasingly using SP Scientific’s Genevac LyoSpeed, a hybrid process combining conventional centrifugal evaporation and lyophilisation, as their preferred method for drying HPLC reverse-phase solvent fractions.
Using LyoSpeed technology on Genevac EZ-2 Elite and Series 3 HT evaporators, HPLC fractions can be automatically concentrated to a few millilitres, then frozen and rapidly lyophilised to produce a diffuse dry powder, which can easily be re-dissolved or weighed out.
Traditional concentration of reverse-phase HPLC fractions to dryness in a Genevac evaporator is a fast and safe process. However, for certain compounds a fully dried result can be hard to achieve due to compound interactions with water, resulting in formation of a gum or oil. Such samples, which are not completely dry, are of little use in biological assays since accurate weights cannot be obtained.
The application of LyoSpeed technology produces, with most samples, a dry powder rather than the traditional thin film, making downstream processing far easier since compounds can be more easily removed from the evaporation vessel. The resultant dry powder is not excessively fluffy as would be obtained from conventional freeze-drying. This avoids the problems associated with static formation, particularly when trying to weigh out such compounds, and also helps prevent the possibility of airborne contamination, especially important if the compound happens to be harmful or even toxic.