Performance of breath-actuated (Qvar) pressurize metered dose inhaler with different spacers: In-vitro study

Background Spacers are commonly used especially for paediatric and elderly patients. However, there is a considerable discussion about their use and operation. The purpose of this study was to examine the performance of different types of spacers with Qvar breath actuated pressurize metered dose inhaler (pMDI) containing Beclometasone with fine particles. Methods The dose evaluation method for pMDIs in the British Pharmacopoeia (BP) was used to find out the total emitted dose (TED) and particle size distribution of Qvar pMDI. The study looked at pMDI alone and with three different spacers (Optimizer, Aerochamber Plus, and Aerochamber MAX) at a flow of 28.3 L/min and 4 L inhalation volume to mimic adults. At different times, from the first to the last actuation, the average amount of drug in each pMDI alone and connected to the three different spacers was evaluated. Results The pMDI by itself had the highest TED, which was significantly higher than all pMDI-spacer combinations (p < 0.05). The spacers also had higher fine particle dose, and fine particle fraction (p<5 µg) then pMDI alone. No significant different was observed in mass median aerodynamic diameter between the four tested combinations. No significant difference was observed between the three evaluated spacer. Conclusions These results show that there are improving effects on aerodynamic characterisation and the amount of drug available for inhalation when spacers are used as inhalational aids to pMDI. That support the GINA recommendation regarding the use of spacer with all patients using pMDI even the breath actuated pMDIs.