Table 2. DD and FPD after storage of fixed-combination BUD/FORM inhalers in 75% RH at both ambient temperature and at 40 °C.

Parameter	Time	Turbuhaler		P value	Spiromax		P value	Easyhaler		P value
		BUD	FORM	BUD	BUD	FORM	BUD	BUD	FORM	BUD
40°/75% RH
DDa μg per dose	Baseline	147	3.0		142	3.6		181	4.0
	1.5 months	151	3.9	0.31	144	3.7	0.29	159	3.8	0.02b
	3 months	151	4.0	0.41	149	3.9	0.04	166	4.0	0.14
FPDc μg per dose	Baseline	86	2.0		68	1.5		71	1.5
	1.5 months	78	1.9	0.01b	61	1.4	0.03	29	0.8	<0.01b
	3 months	70	1.8	<0.01b	61	1.6	<0.01b	23	0.8	<0.01b
Ambient temp/75% RH
DDc μg per dose	Baseline	147	3.8		142	3.6		181	4.0
	1.5 months	145	3.6	0.58	147	4.0	0.11	190	4.5	0.37
	3 months	154	4.1	0.07	143	4.0	0.63	172	4.3	0.34
FPDc μg per dose	Baseline	86	2.0		68	1.5		71	1.5
	1.5 months	81	1.8	0.16	62	1.6	<0.01b	44	1.1	<0.01b
	3 months	82	2.0	0.07	63	1.7	0.02b	47	1.2	<0.01b

Abbreviations: API, Active Pharmaceutical Ingredient; BUD, Budesonide; DD, delivered dose; FORM, formoterol; FPD, fine-particle dose; NGI, Next-Generation Impactor; RH, relative humidity.

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

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

^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).