Effect of Low Temperatures on Drug-Delivery Efficacy of Aerosols

Abstract

Objective:

To determine how low temperatures affect the pharmaceutical properties of oral inhalation aerosols pressurized with chlorofluorocarbons (CFCs).

Design:

Inhalation aerosols of the beta-adrenergic receptor agonist terbutaline sulfate were exposed at three different environmental temperatures [22, 0, and −10 °C; (±2)]. Three groups of 10 canisters each, at different drug loads (100%, 50%, and 20%), were studied at these temperatures. Canisters with mouthpieces were weighed before and after 40 actuations in order to study the mass propelled in each experimental condition. Photographs were also taken of the aerosol mist at each temperature.

Results:

A statistically significant decrease in the average mass of the aerosol discharged was evidenced at low temperatures. The temperature and aerosol output were linearly correlated. The weight loss at–10 °C was 35.4%. At this temperature the emitted doses were discharged as liquefied droplets. This effect was quickly manifested and proved reversible.

Conclusions:

Low temperatures modify the pharmaceutical properties of oral inhalation aerosols pressurized with CFCs. This technical information should be included as a note of caution in the prescribing information.