1. Drying of streptomycin under vacuum under dynamic or static conditions is completed in identical time; while drying of penicillin under dynamic conditions offers the possibility of intensifying drying about two-fold compared to static conditions. 2. An appreciable intensification of the drying process may be attained when only mechanically bound liquid is present; in this connection, before selecting a constructional design of a drying process, it is necessary to establish the nature of the bond between moisture and material.