Abstract
The emitted dose and mass median aerodynamic diameter of active ingredients from dry powder inhaler (DPI) are reported to be affected by the type of device, procedure and the inhalation flow rate of the patients. The purpose of this study was to clarify the effect of device shaking on the emitted dose of active ingredient from reservoir DPI by using Dosage Unite Sampling Apparatus (DUSA). A procaterol hydrochloride (PH)-containing DPI, Meptin® Clickhaler®, was used as a model DPI requiring shaking before use. After shaking by 7 test collaborators following the patient instructions, the amount of PH emitted into the DUSA using a vacuum pump was determined by high-performance liquid chromatography. Without device shaking, the emitted dose of PH was markedly low and varied widely, and the result suggested that device shaking was prerequisite for the efficient emission of active ingredient from DPI. The amount of PH emitted after shaking of the device varied largely between 7 test collaborators, while their averages were more than 80% of the labeled amount. In one collaborator, the ratio of emitted dose varied up to 30% among 4 experiences. Tapping the device before use also enabled the efficient emission of PH. Smaller particles were observed in Meptin® Clickhaler® compared to those in other reservoir DPIs that do not require shaking may explain the importance of shaking before use. These results confirmed the relevance of advice including the shaking methods by health-care personnel for appropriate use of the DPI formulations.
