R

from a calculation similar to that discussed above for sedimentation. Calculated inertial deposition shows a dependence on particle size as follows; 10 pm particles 50%, 7 pm particles 33%, leading to 20% for 5 pm particles, and 1% for 1 pm particles.

9.9.2 Experimental observations

The complexity of the respiratory system prevents a precise mathematical approach to the problem. Many clinical studies, however, clearly demonstrate the importance of particle size.

Particles of hygroscopic materials are removed more effectively than are nonhygro-scopic particles, because of the growth of these

5 mm PARTICLES

Insoluble drug

5 mm PARTICLES

0 0

Post a comment