GENERATION OF STABLE TEST ATMOSPHERES OF COCAINE BASE AND ITS PYROLYZATE, METHYLECGONIDINE, AND DEMONSTRATION OF THEIR BIOLOGICAL-ACTIVITY

Generating controlled test atmospheres of known chemical identity and airborne concentration upon demand is a significant technical obstacle that limits the scope and repeatability of studies of inhaled substan ces. We addressed this problem as applied to the generation of atmosph eres that result from heating crack cocaine, which include both cocain e and its pyrolyzate methylecgonidine (MEG). A condensation aerosol ge nerator was used to generate atmospheres comprised of monodisperse par ticles of cocaine, MEG, or mixtures of both that are of submicron size suitable for deposition in the alveolar region of primates. Compresse d air seeded with nanometer-size sodium chloride particles was passed through a constant depth of molten cocaine or MEG in a bead bed, rehea ted, and condensed to an aerosol within an annulus of cold air. To ach ieve control of a mixture of both compounds, MEG was condensed onto co caine particles in a separate coating step. On-line analytical instrum ents provided verification of airborne concentration, estimates of par ticle size, and dispersion as well as chemical identity. Specific airw ay conductance (SGaw), heart rate, and rectal and skin temperatures we re measured in squirrel monkeys breathing atmospheres containing conde nsation aerosols of cocaine or MEG free base. SGaw was reduced after i nhalation of either base, and both induced temperature and cardiovascu lar changes, demonstrating that the aerosols so generated had biologic al activity. Copyright (C) 1996 Elsevier Science Inc.