The Mixing Inlet from Copley Scientific allows application of a patient-representative inhalation profile during aerodynamic particle size distribution (APSD) measurement and is used to achieve better in vitro in vivo correlations (IVIVCs). Available in both Andersen Cascade Impactor (ACI) or Next Generation Impactor (NGI) versions, the inlet has a 316 stainless steel construction to aid drug recovery and optimize drug/solvent compatibility. Its one-piece, rigid design offers enhanced induction port support and protects the sharp edge of the inner cone from damage. Avoidance of internal “O” rings eliminates a potential source of leaks. By gently mixing sample-laden air with any supplementary air required, the inlet produces a homogeneous test flow for the impactor, while minimizing internal drug losses.