Simulation and validation of computational fluid dynamics used for selected inhalation device of Rehmanniae Radix oligosaccharide dry powder inhalation / 中草药

ABSTRACT

Objective: To simulate the kinematics of drug particles in two kinds of dry powder inhalation devices for Rehmanniae Radix oligosaccharide dry powder inhalation (RRODPI) by computational fluid dynamics (CFD), and to compare simulation results with the in vitro deposition results in order to verify the accuracy of the results. Methods: NGI was used to carry out in vitro deposition experiments, and the relative experiment data were obtained. UGNX 10.0 software was adopted to establish three-dimensional models of two kinds of dry powder inhalation devices according to their actual sizes, and then the models were imported into ICEM CFD software to divide mesh. After checking mesh quality, mesh was imported to Fluent software and the related parameters were set. When the data was in steady state after iteration and convergence, the data analysis was carried out; Finally the kinematics results of drug particles at three kinds of particle sizes in two kinds of dry powder inhalation devices were gained. The kinematics results were compared with the in vitro deposition results to verify the simulation results. Results: In vitro deposition experiment results showed that the effective deposition rate in twister was higher than that in osmohaler. CFD results showed that drug particles at different sizes in twister could all reach the outlet but for drug particles in osmohaler, it could not reach the outlet at a certain range of sizes. The two results showed that twister was more suitable for the dry powder inhaler device of RRODPI. Conclusion: It is comparatively intuitive to use CFD to carry out the kinematics simulation of drug particles in two kinds of dry powder inhalation devices and the result is consistent with the in vitro deposition experiment results, which can well predict the motion state of drug particles in the two dry powder inhalation devices.