Fluticasone Propionate

DD and FPD were determined by using the sampling apparatus and procedures described in European Pharmacopoeia 8.0; for each flow rate evaluated, 4 L of air was drawn through the inhaler.^{(24 )}Salmeterol and Fluticasone propionate collected in the sampling apparatus were analyzed by high-performance liquid chromatography method with UV detection at 280 nm. The chromatographic separations were carried out at 40°C on an Inertsil ODS-3 C18, 3 μm, 4.0 × 150 mm analytical column (GL Sciences) using 100 μL injection volume. The mobile phase, methanol:0.02 M phosphate buffer, pH 6.2 (25:75), was delivered at a flow rate 1 mL/mL. The samples were dissolved in water:acetonitrile 50:50 (v/v) and sample volume was 50 mL for DD samples and varied from 10 to 65 mL for FPD samples. The quantitation limit of the method for Salmeterol was 0.03 μg/mL and for Fluticasone Propionate, 0.1 μg/mL. The relative standard deviation of the peak areas varied not more than 2% during analysis.
For assessments of DD, a total of 36 devices were tested (three devices for each flow rate and strength/batch). Ten doses were measured for each inhaler, and the mean DDs were calculated.
FPD was defined as the amount of particles with an aerodynamic diameter ≤5 μm. FPD was determined using Next Generation Impactor (NGI, apparatus E).^{(24 )} The cutoff points for impactor stages were calculated in relationship to the used flow rates according to European Pharmacopoeia 8.0,^{(24 )} and FPD was derived from the data. For each FPD analysis, 10 doses were discharged into the NGI.

This study will include patients treated with ICS approved for asthma treatment in Denmark, including combination treatment with LABAs and/or LAMAs. The following drugs have been defined as IMPs (investigational medicinal product) in the study (approved by the Danish Medicines Agency): Budesonide (ATC: R03BA02), fluticasone propionate (ATC: R03BA05), mometasone furoate (ATC: R03BA07), fluticasone furoate (ATC: R03AK10), beclometasone dipropionate (ATC: R03BA01), and ciclesonide (ATC: R03BA08).
The study drugs will be additionally labelled (not covering the original label) with the following information: Name of sponsor/investigator, trial reference code “PERIOSTIN”, trial site, and participant ID (randomization number).

A schematic representation
of the IPAP-FESTA
pulse sequence is shown in Figure 1. It can be described as a doubly selective modulated
echo followed by a TOCSY transfer, similar to MODO-FESTA.^{35 (link)} The resulting spectrum shows only ¹H signals that are in the same spin system as that of a specific ¹⁹F site. IPAP-FESTA contains four variations of the modulated
echo, resulting in the acquisition of two complementary sets of interleaved
IP and AP data. Within each data set, modulated and unmodulated data
are acquired by changing the phase of the excitation 90° ¹H pulse (ϕ₁ = x on odd-numbered
scans, ϕ₁= −x on even-numbered
scans) and using different arrangements of ¹⁹F selective
iBURP pulses and delays in odd- and even-numbered scans. The delay
Δ is set to 1/2J_HF for A_nX and A_nX₃ spin systems and 1/4J_HF for A_nX₂ spin systems, where n is the number of equivalent protons and J_HF is the heteronuclear coupling constant between the selected fluorine
and proton(s). Note that the second iBURP ¹⁹F pulse is
time-reversed with respect to the first, to refocus any J_HF evolution that occurs during the first pulse.^{33 (link),39 (link)} In each data set, identical signals are obtained in odd- and even-numbered
scans for the selected protons, while all other protons yield equal
but opposite phases and, therefore, are suppressed by summing the
two scans. Field gradient pulses flank the selective ¹H
shaped pulse for coherence transfer pathway selection. A hard 90° ¹H pulse is applied after the modulated echo, with the phase
ϕ₂ of the pulse depending on whether IP (ϕ₂ = x) or AP (ϕ₂ = −x) data are being acquired. For the TOCSY transfer, DIPSI-2
is used as the isotropic mixing element,^{40 (link)} transferring the IP or AP magnetization from the selected ¹H signal to all other spins within the same spin system. Zero-quantum
suppression elements are applied on either side of the DIPSI-2 element,
together with a purge gradient pulse, to suppress the effects of zero-quantum
coherences and of unwanted transverse magnetization.^{41 (link)} A final 90°_x¹H pulse transfers all desired magnetization to the transverse plane
for observation. An additional phase-cycled 90° ¹⁹F pulse is applied simultaneously to the 90° ¹H pulse
in IP-MODO-FESTA, to ensure that any remaining AP contributions are
suppressed before data acquisition and to give pure IP signals. The
result is that only proton signals from the selected ¹H–¹⁹F spin system, IP or AP with respect to the J_HF coupling to the specified ¹⁹F survive with
any other signals being suppressed. SRI-FESTA^{34 (link)} could potentially be used instead of MODO-FESTA; however the higher
sensitivity of the latter is advantageous when analyzing dilute mixtures
such as the fluticasone propionate mixture described here. Further
details are provided in the SI.