Glass Expansion Chambers

The majority of nasal products are designed to generate droplets/particles with a mass median aerodynamic diameter (MMAD) of greater than 10 to 20 microns. This is to increase nasal deposition and minimise deposition in the lungs. However, most sprays deliver a proportion (typically <5%) of fine droplets in the <10 micron range. It is important to quantify this Fine Particle Dose (FPD) since it can penetrate beyond the nasal tract and into the lower respiratory tract or lungs, which may be undesirable. Cascade impactors are designed to capture particles in the range 0 to 10 microns and are widely used for this application.

NGI with Glass Expansion Chamber

The use of a cascade impactor in conjunction with a high volume expansion chamber is used to measure the amount of drug in small particles or droplets in respect of nasal sprays and aerosols. In accordance with the draft guidance, we offer a range of glass expansion chambers to meet these requirements. We offer 3 sizes:

  • 1 L chamber: to maximise drug deposition below the top stage of the impactor (i.e. for nasal aerosols)

  • 2 L chamber: to maximise aerosolisation and impactor deposition (i.e. for nasal sprays)

  • 5 L chamber: for powerful nasal sprays where increased space is required to generate full plume