EVALUATION OF AEROSOL DRUG OUTPUT FROM THE OPTICHAMBER(TM) AND AEROCHAMBER(R) SPACERS IN A MODEL SYSTEM

Metered-dose inhalers (MDIs) are an effective means of generating drug -containing aerosols targeted for delivery to intrapulmonary airways. Many problems associated with incorrect patient use of MDIs are mitiga ted by adding a valved spacer device to the inhaler mouthpiece. This i n vitro study compared the efficiency of drug output through a new spa cer device, OptiChamber(TM) (HealthScan Products Inc., Cedar Grove, NJ ), to that of a device commercially available since the 1980s, AeroCha mber(R) (Monaghan Medical, Plattsburgh, NY). Testing utilized MDI form ulations of albuterol, beclomethasone dipropionate, and cromolyn sodiu m. OptiChamber equaled or, in the majority of cases, exceeded AeroCham ber in output of the three drugs at two simulated inspiratory flow rat es. Drug output from OptiChamber was found to be less sensitive to cha nges in flow rate than that from AeroChamber. OptiChamber also showed less decrease in drug output than AeroChamber when time delays were in troduced between MDI actuation and the start of a simulated inhalation . Mass median aerodynamic diameters of drugs exiting the two spacers w ere generally similar to those of drugs exiting the MDI alone. However , spacers were shown to nearly eliminate the output of large-size drug particles (>5.8 mu m), which can result in oropharyngeal drug deposit ion. Emitted fine-particle drug (<5.8 mu m) doses from OptiChamber wer e greater than those from AeroChamber with or without a delay between canister actuation and the start of a simulated inhalation. The result s suggest that OptiChamber may provide more efficacious aerosol drug d elivery than AeroChamber under both ideal and suboptimal conditions.