Un développement nouveau de la lyophilisation: La cryodessiccation des systèmes non aqueux

Summary A new development is made to enlarge the field of lyophilization using non-aqueous media. Unstable compounds are preserved by freezing and drying their solutions in organic solvents. The same technique applied to chemicals dissolved in liquid ammonia enables the preparation of stable concentrated free radicals, due to the very low temperature of sublimation of frozen NH₃. Finally, experiments are made demonstrating the possibilities of high velocity, low temperature sublimation of solutions in solid CO₂ at normal atmospheric pressure.