国生 国生 Formulations are usually solution. ©Nebulizer Suspensions can also be formulated. ·Air jet system However,particle size of drug must be ·Ultrasonic system significantly smaller than the droplet size. The formulation must be sterile and isotonic to avoid stimulation of pulmonary tract. 国丝生一 圈上生 ®Air--jet nebulizer ©Air-jet nebulizer .Air-jet nebulizer devices .A high-pressure stream of gas stream exits the orifice utilize a pressurized gas .The high speed jet produces low lateral pressure at the outlet to create the aerosol It draws the liquid into the gas stream Drug particles. The high shear shatters the liquid into droplets 国垫生 圈生 ®Air-jet nebulizer ®Air-jet nebulizer ·Baffle Emitted droplets size depends on Large droplets impact on the Jet design,orifice diameter baffle surface and fall back .Gas pressure,density and flow rate Fine aerosol exit the air-jet Concentration,surface tension and viscosity of nebulize. drug solution 99 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 Nebulizer • Air jet system • Ultrasonic system Shanghai Jiao Tong University Air-jet nebulizer • Air-jet nebulizer devices utilize a pressurized gas to create the aerosol particles. Shanghai Jiao Tong University Air-jet nebulizer • A high-pressure stream of gas stream exits the orifice • The high speed jet produces low lateral pressure at the outlet • It draws the liquid into the gas stream • The high shear shatters the liquid into droplets Shanghai Jiao Tong University Air-jet nebulizer • Baffle • Large droplets impact on the baffle surface and fall back • Fine aerosol exit the air-jet nebulize. Shanghai Jiao Tong University Air-jet nebulizer • Emitted droplets size depends on • Jet design, orifice diameter • Gas pressure, density and flow rate • Concentration, surface tension and viscosity of drug solution