Salmeterol inhaler using a non-chlorinated propellant, HFA134a: Systemic pharmacodynamic activity in healthy volunteers

Abstract

Background - Metered dose inhalers for the treatment of asthma use chlorofluorocarbons as propellants. These face an international ban due to their effect on the ozone layer. Salmeterol has been reformulated using the non-chlorinated propellant Glaxo inhalation grade HFA134a. Methods - The safety, tolerability and systemic pharmacodynamic activity of the salmeteroIVHFA134a inhaler, the current salmeterol inhaler, and placebo (HFA134a) were compared in 12 healthy volunteers in a double blind, randomised crossover study using a cumulative dosing design. Results - Safety and tolerability were similar and the response was related to the dose over the range used (50-400 pg) with both salmeterol inhalers. The salmeteroV HFA134a inhaler showed no differences from the current inhaler for pulse rate, blood pressure, tremor, QT, interval, and plasma glucose levels. The salmeteroV HFA134a inhaler had significantly less effect on plasma potassium levels. Conclusions - In healthy volunteers the sahmeterolVHFA134a inhaler is at least as safe and well tolerated as the current salmeterol inhaler, and has similar systemic pharmacodynamic activity.