国生一 国生 ④Evaluation of MDI ④Nebulizer Leakages and weaknesses Liquid content is atomized by Emitted time and emitted dose mechanical pressure. Particle size distribution Produce a constant stream of aerosol Emitted rate and emitted amount particles. ·Sterile Formulations and devices are ·Microorganism developed by independent companies. 国生一 国生 Nebulizers enable treatment of patients that Drawbacks of traditional nebulizers require higher doses of drug .Cumbersome have difficulties with conventional inhalers ·Long timescale Have a complexity of device assembly with low efficiency and high variability in drug delivery 国生 圈生 Formulations are usually solution. ©Air-jet nebulizer Suspensions can also be formulated. Air-jet nebulizer devices utilize a pressurized However,particle size of drug must be gas to create the aerosol particles.The gas significantly smaller than the droplet size. stream is passed over the solution,creatinga liquid film.This film breaks apart due to The formulation must be sterile and breakage of surface tension forces,forming isotonic to avoid stimulation of pulmonary aerosol particles tract. 66 Shanghai Jiao Tong University Evaluation of MDI • Leakages and weaknesses • Emitted time and emitted dose • Particle size distribution • Emitted rate and emitted amount • Sterile • Microorganism Shanghai Jiao Tong University Nebulizer • Liquid content is atomized by mechanical pressure. • Produce a constant stream of aerosol particles. • Formulations and devices are developed by independent companies. Shanghai Jiao Tong University Nebulizers enable treatment of patients that • require higher doses of drug • have difficulties with conventional inhalers Shanghai Jiao Tong University Drawbacks of traditional nebulizers • Cumbersome • Long timescale • Have a complexity of device assembly with low efficiency and high variability in drug delivery Shanghai Jiao Tong University Formulations are usually solution. Suspensions can also be formulated. However, particle size of drug must be significantly smaller than the droplet size. The formulation must be sterile and isotonic to avoid stimulation of pulmonary tract. Shanghai Jiao Tong University Air-jet nebulizer • Air-jet nebulizer devices utilize a pressurized gas to create the aerosol particles. The gas stream is passed over the solution, creating a liquid film. This film breaks apart due to breakage of surface tension forces, forming aerosol particles