1  Asuitable cascade impactor is available as Model Mk IIfrom Graseby Inc.,500Technology Court,Smyrna,GA,30082.The impactor is used without the preseparator.The inhaler is connected to the impactor via the induction port,atop the entrance cone shown in Figure 4.If an equivalent impactor is employed,the induction port in Figure 4a should be used,although the entrance cone (Figure 4b)should be replaced with one to fit the impactor in question.Note that the internal surfaces of the induction port(Figure 4a)are designed to fit flush with their counterparts in the entrance cone (Figure 4b).This design avoids aerosol capture at the junction of the two pipes.

2  The cascade impactor is available as the Model 160Marple-Miller Impactor from MSP Corporation,Minneapolis,MN.The inhaler should be connected to the impactor via the induction port,shown in Figure 4a.

3  The cascade impactor is available as the Andersen 1ACFM Non-Viable Cascade Impactor (Mark II)from Graseby Inc.,500Technology Court,Smyrna,GA,30082.The impactor is used with the preseparator.

4  The five-stage impinger is available from Copley Instruments,plc,Nottingham,UK.The inhaler should be connected to the impactor via the induction port,shown in Fig.4and 4a.

5  The cascade impactor is available as the Next Generation Pharmaceutical Impactor from MSP Corporation,Minneapolis,MN.