Processing device (1, 101, 201) for processing one or more flowable materials, such as pharmaceuticals, the processing device (1, 101, 201) comprising: a housing (2, 102) having a cylindrical processing chamber (3, 103), and having an inlet (30, 130, 230) in fluid communication with the processing chamber (3, 103), and an outlet (35, 135) in fluid communication with the processing chamber (3, 103) and at a distance from the inlet (30, 130, 230) in a direction along the longitudinal direction of the cylindrical processing chamber (3, 103); and an agitating rotor (40, 240) arranged axially within the processing chamber (3, 103) and configured for agitating one or more flowable materials within the processing chamber (3, 103), wherein the agitating rotor (40, 240) is configured to rotate to agitate the one or more flowable materials within the vessel to such an extent that the one or more flowable materials are maintained as an annular fluidized bed within the cylindrical processing chamber (3, 103), wherein the processing device (1, 101, 201) further comprises a dust directing member (50, 150, 250) arranged at the agitating rotor (40, 240) and at or near the outlet (35, 135), and configured for substantially preventing a cloud of dust within the processing chamber (3, 103) from reaching the outlet (35, 135) and for directing the cloud of dust towards the annular fluidized bed, therewith introducing the cloud of dust into the annular fluidized bed, wherein the dust directing member (50, 150, 250) has a substantially circular directing body extending substantially transverse to the longitudinal direction of the agitating rotor (40, 240), wherein the cylindrical processing chamber (3, 103) is a circular cylindrical processing chamber (3, 103) having a first diameter, wherein the substantially circular directing body has a second diameter, wherein the second diameter is smaller than the first diameter, and wherein the cylindrical processing chamber (3, 103) has a cylindrical inner surface (21, 121, 221) and the substantially circular directing body has an outer circumference, wherein a distance between the cylindrical inner surface (21, 121, 221) of the cylindrical processing chamber (3, 103) and the outer circumference of the substantially circular directing body is in the range between 2 and 20 mm, for example is 3 mm when the first diameter is approximately 134 mm, or in the range between 1% and 17%, preferably between 1.5% and 15%, of the first diameter. a housing (2, 102) having a cylindrical processing chamber (3, 103), and having an inlet (30, 130, 230) in fluid communication with the processing chamber (3, 103), and an outlet (35, 135) in fluid communication with the processing chamber (3, 103) and at a distance from the inlet (30, 130, 230) in a direction along the longitudinal direction of the cylindrical processing chamber (3, 103); and an agitating rotor (40, 240) arranged axially within the processing chamber (3, 103) and configured for agitating one or more flowable materials within the processing chamber (3, 103), wherein the agitating rotor (40, 240) is configured to rotate to agitate the one or more flowable materials within the vessel to such an extent that the one or more flowable materials are maintained as an annular fluidized bed within the cylindrical processing chamber (3, 103), wherein the processing device (1, 101, 201) further comprises a dust directing member (50, 150, 250) arranged at the agitating rotor (40, 240) and at or near the outlet (35, 135), and configured for substantially preventing a cloud of dust within the processing chamber (3, 103) from reaching the outlet (35, 135) and for directing the cloud of dust towards the annular fluidized bed, therewith introducing the cloud of dust into the annular fluidized bed, wherein the dust directing member (50, 150, 250) has a substantially circular directing body extending substantially transverse to the longitudinal direction of the agitating rotor (40, 240), wherein the cylindrical processing chamber (3, 103) is a circular cylindrical processing chamber (3, 103) having a first diameter, wherein the substantially circular directing body has a second diameter, wherein the second diameter is smaller than the first diameter, and wherein the cylindrical processing chamber (3, 103) has a cylindrical inner surface (21, 121, 221) and the substantially circular directing body has an outer circumference, wherein a distance between the cylindrical inner surface (21, 121, 221) of the cylindrical processing chamber (3, 103) and the outer circumference of the substantially circular directing body is in the range between 2 and 20 mm, for example is 3 mm when the first diameter is approximately 134 mm, or in the range between 1% and 17%, preferably between 1.5% and 15%, of the first diameter.