Assessment of the cough reflex caused by inhalation of sodium lauryl sulfate and citric acid aerosols.

Guinea pigs were exposed for thirty minutes to a particulate aerosol of sodium lauryl sulfate at concentrations of 17.3, 28.9 and 48.6 mg/m3. The exposure chamber in which individual guinea pigs were exposed was fitted with a microphone to record coughing. As the concentration of sodium lauryl sulfate increased, the combined number and severity of the coughs increased and a fade in the response was also observed with exposure duration. Citric acid, a tussigenic agent commonly used to test antitussive agents was also tested using the same experimental protocol and was found to be about an order of magnitude less potent than sodium lauryl sulfate. This model could be useful in assessing the irritating properties of various aerosols to the tracheo-bronchial tree.