[CHARACTERISTICS OF BUDEFORU® FOR BUDESONIDE AND FORMOTEROL MIXTURE].

BACKGROUND: Recently, BudeForu® (BF), a generic of Symbicort Turbuhaler® (SMB), is widely used in Japan. Although appearance of BF resembles to SMB, several differences in length, weight, and side-hole sizes are seen with precise inspection. As particle releases from the inhalation device is strongly influenced by its mechanical characteristics, we compared their particle release patterns. METHODS: An inhalation simulator generated either ramp-up or triangular (time to reach peak inhaling flow (PIF) = 0.42 s) inhalation pattern. Time trajectories of inhaled flow and released particles from either device were depicted with a photo-reflection method. Internal resistances of them were also measured. RESULTS: Particle release patterns of both dry powder inhalers resembled each other. Immediately after release from the inhaler, they reached the peak value and then completed in 0.5 s. In either ramp-up or triangular inspiration pattern, a single burst developed at early inhalation. There were linear relationships between PIFs and emitted doses. The regression lines using ramp-up patters were: Y = 0.00241 X - 0.039, r2 = 0.700, p ＜ 0.0001 (BF), Y = 0.00210 X - 0.038, r2 = 0.654, p ＜ 0.0001 (SMB), and those using triangular patterns were: Y = 0.00223X － 0.0015, r2 = 0.445, p ＜ 0.0001 (BF), and Y = 0.00229X － 0.0023, r2 = 0.687, p ＜ 0.0001 (SMB). Internal resistances of the BF and SMB were 0.105±0.004 and 0.119±0.105 cmH2O0.5/L/min respectively. CONCLUSIONS: Present experimental study suggested that aerodynamic characteristics of BF were quite similar to those of SMB.

[IS IT NECESSARY TO PROHIBIT SIDE-HOLE CLOSURE IN USE OF THE DRY POWDER INHALERS?]

BACKGROUND: In use of Ellipta (EPT), Diskus (DKS) or Turbuhaler (TBH), an instruction not to close side holes is sometimes given, but validity of such instruction has not been proved. METHOD: Using an inhalation simulator we measured peak inhaled flow (PIF), peak inhaled pressure (PIP) and amount of the drug release from these DPIs before and after closure of side holes (SHC). In the case of EPT, incomplete obstruction was also assessed. RESULTS: SHC increased internal resistance by 2.8 times in TBH, 1.0 in DKS, and 1.28 (incomplete obstruction) and 1.86 (complete) in EPT. Inhaled flows at pressure of -15cmH2O were 14L/min in TBH, 47 in DKS and 34 in EPT (incomplete obstruction). SHC suppressed drug release from TBH but statistical significance was not obtained. Drug release was not suppressed by SHC in DKS, while it was almost half during SHC in EPT. The level of PIF decreased by SHC was serious since fine particles generation is not expected. Such severe decreases were not found in DKS and EPT. CONCLUSION: SHC severely inhibited drug release from TBH, but almost no effects on DKS. Such negative effect was limited in usual use of EPT.