The double-blister Dry Powder Inhaler designed by ELPEN was simulated by SIMTEC, to verify its ability to disperse the drug properly. The drug delivery principle relies entirely on the appropriate aerodynamic design of the inhaler’s internal space, so that patient receives the necessary dose. After the patient places the drug on the two blisters, breathing-in from the mouthpiece forces air to enter in the device. The air stream splits in two parts, one of which passes through the blisters and carries the drug particles. The two streams reunite, before entering the oral cavity of the patient.
The developed CFD model calculated the flow inside the inhaler and was successfully validated against experimental data. Then, the powder particles were tracked, to calculate the residence time and the characteristics of the particles that exit the inhaler. It was shown, that even for a low suction pressure produced by a weak patient, large enough velocities and high turbulence levels occur. This ensures the separation of the powder from the blisters and the strong mixing of the two stream parts inside the cone region. All particles exit in less than 0.5 seconds, guaranteeing the proper entering of the drug to the patient’s mouth. The study provided ELPEN scientists with useful information, to evaluate the critical design parameters.
ANSYS tools: ANSYS FLUENT