Question

1. What is the primary method of deposition for large, high-mass particles?
2. Particles of 10 microns or larger tend to deposit in what part of the respiratory tract? What about particles between 5 and 10 microns?
3. What other substances are found in MDIs that may produce clinical problems?

Answer 1

Question-1-Answer

Impaction,sedimentation and diffusion are the major deposition mechanisoms for particles.Airway geometry and resultant airflow patterns interact with these mechanisms to determine deposition sites.Gases and vapors like very small particles deposit due to diffusion.A particle jagged,rough ends has a high rate of deposition.

Relative to total airborne partilces,the particle size having 50 percentage penetration for the thoracic and respirable fractions are 10 microns and 4 microns.

Question-2-Answer

Typically most particles greater than 10 microns are deposited in nose,throat and can not penetrate the lower tissues of Respiratory tract.

The size ranging from 5-10 microns will deposit in Larger bronchioles through Nasal passage.

Question-3-Answer

The substance found in MDIs that produce clinical problems are the following

1.Soya lecithin

2.Sorbitan

3.Oleic acid....

These three are Dispersal agents substance are Dispersal agents.