The main objectives of this work were to assess precision capsule filling of a DPI carrier-based formulation using a commercial scale dosator-based unit from MG2 (TEKNA) and evaluate the impact of filling process parameters on the powder in-vitro aerodynamic performance.
Size 3 capsules were efficaciously filled with 20 mg, varying layer depth in the rotary container (7 – 12 mm) and filling speed (14000 and 20000 capsules/hour). The dosing chamber height was adjusted automatically by the MultiNETT system in order to reach the targeted fill weight. TEKNA unit was equipped with nine dosators, with 2.8 mm of diameter. The study showed that the degree of compaction in the dosing chamber is a key parameter to achieve a feasible capsule filling process. On one hand, increasing filling speed increased rejection rate: it was challenging to maintain a homogeneous powder layer. On the other hand, increasing the run time seems to decrease the rejection rate.
Higher filling speeds may minimize powder densification in the capsule, resulting in higher emitted doses. Nonetheless, this positive impact is not observed in the fine particle dose. More studies are needed to identify the key parameters bridging manufacturability and performance at commercial scale.