Chemical Evaluation of the Beeswax Pellet Implantation Bioassay Model for Studies of Environmental Carcinogens 2

Abstract

The release properties of a number of constituents of cigarette smoke condensate in a condensate-beeswax matrix were characterized by an in vitro study. Eighteen compounds that were representative of several classes of condensate components were tested. Equal quantities of condensate and beeswax, mixed with tracer quantities of the ¹⁴C-Iabeled test compounds, were formed into rod-shaped pellets similar to those used for trachea implant studies, and the rate at which the ¹⁴C was removed from the pellet by a flowing saline stream was monitored. Results indicated a wide range in the rates at which the test compounds were released from the pellets. The smaller and water-soluble molecules were released rapidly; about 90% of the nicotine and phenol were leached out in the first 24 hours. Larger and less soluble molecules were released slowly or not at all. Only about 10% of the stearic acid and essentially none of the benzo[a]pyrene was released in 28 days. The effects of such an uneven release of components from an implantation of biologically active material in an inert carrier matrix are discussed with regard to bioassay systems.