Table 1. DD and FPD after storage of single BUD inhaler in 75% RH at both ambient temperature and at 40 °C.

Parameter	Time	Turbuhaler	P value	Novolizer	P value	Easyhaler	P value
40 °C/75% RH
DDa μg per dose	Baseline	138		192		198
	1.5 months	119	0.12	165	0.04	151	0.01b
	3 months	150	0.33	193	0.94	168	0.07
	6 months	120	0.10	163	<0.01b	125	<0.01
FPDc μg per dose	Baseline	74		78		54
	1.5 months	66	0.19	71	0.15	20	<0.01b
	3 months	79	0.38	73	0.25	21	<0.01b
	6 months	63	0.04	68	0.02	20	<0.01b
Ambient temp/75% RH
DDa μg per dose	Baseline	138		192		198
	1.5 months	NTd		NTd		170	0.10
	3 months	134	0.67	209	0.22	179	0.25
	6 months	127	0.24	165	0.01e	149	<0.01b
FPDc μg per dose	Baseline	74		78		54
	1.5 months	NTd		NT		33	<0.01e
	3 months	72	0.67	85	0.15	30	<0.01e
	6 months	66	0.11	71	0.06	25	<0.01e

Abbreviations: API, Active Pharmaceutical Ingredient; DD, delivered dose; FPD, fine-particle dose; NGI, Next-Generation Impactor; NT, not tested; RH, relative humidity.

^aDD is defined as the total amount of API delivered to the NGI.

^bStatistically significant, applying Bonferroni’s correction for three comparisons (P<0.0167=0.05/3).

^cFPD is defined as the amount of API contained in particles <5 μm in size, and the amount was calculated using interpolation between relevant stages, which depend on the flow rate (stage cutoffs vary with varying flow rate).

^dOnly Giona Easyhaler was tested after storage for 1.5 months at ambient/75% RH, as this was a conditional test carried out only if significant changes were observed after storage at 40 °C/75% RH for 6 weeks.

^eStatistically significant, applying Bonferroni’s correction for two comparisons (P<0.025=0.05/2).