A closed inhalation system for pharmacokinetic and metabolism studies of volatile compounds with small laboratory animals.

In the inhalation system described an animal can be kept in the same atmosphere of a 2-liter desiccator for up to 24 h. The expired carbon dioxide is adsorbed with soda lime and the resulting reduced pressure is balanced by a supply of oxygen also used for the inflow of the chemical to be investigated. Urine and faeces can be collected separately and the system allows a periodical control of the concentration of the chemical by sampling the air with needle and syringe.