This document summarizes pulmonary drug delivery systems. It discusses the anatomy and physiology of the lungs and factors that affect drug deposition. It describes advantages like direct delivery to the site of action that reduces needed doses. Current technologies discussed include nebulizers, pressurized metered-dose inhalers, and dry powder inhalers. Challenges from mucus, clearance and barriers are addressed. The conclusion is that pulmonary delivery directly targets lungs for local and systemic effects, though modifications are still needed to overcome physiological limitations.

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PULMONARY DRUG DELIVERY SYSTEM
PREPARED BY: PROF. SHASHANK
CHAURASIYA
BANSAL COLLEGE OF PHARMAY, BHOPAL 1

2.  Introduction
 Objective
 Anatomy & physiology of lungs
 Factors affecting on pulmonary drug delivery system
 Advantages & disadvantages
 Applications
 Aerosols
 Mechanism of pulmonary absorption
 Current technologies
Drugs given by pulmonary route:
 Conclusion
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3. Pulmonary drug delivery is primarily used to treat conditions
of the airways, delivering locally acting drugs directly to their
site of action.
 Delivery of drugs directly to their site of action reduces
the dose needed to produce a pharmacological effect.
 As the lung is able to absorb both water and oil into the
tissue, this is not a restriction of pulmonary delivery.
 Carriers like micro particles, nanoparticles, liposomes
can be used in lung targeting
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5. Increasing the inspiratory flow rate (IFR) will enhance
deposition
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PHYSIOLOGICAL FACTORS PARTICLE DEPOSITION IN
THE AIRWAYS
Lung morphology
shortest average pathlength will show greatest peripheral
deposition.
Oral vs Nasal breathing
In nose breathing particles are deposited in the nose and
pharynx, Hence for pulmonary drug delivery, the aerosols are
inhaled via the mouth.
Inspiratory flowrate
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volume of air inhaled in one breath, the “Tidal volume”.
Breathholding
Increasing the time between the end of inspiration and the
start of exhalation increases the time for sedimentation to
occur.
Disease state
Bronchial obstruction result in localized deposition in the
larger airways of the TB region.
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Sizeand Density
Less than 5 µm sutable & densities of 0.4 g cm−3 are efficiently
deposited in the lungs.
Shape
•Particles which are non-spherical will have at least one physical dimension
which is greater than the aerodynamic diameter.Particle shape should be uniform.
Density
Large porous particles with physical diameters of 20 μm and
Physical stability
DPIs may be hygroscopic and,99.5% RH 37 0C greater chance of being
prematurely deposited. 7

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Mucus barrier
The first barrier
•The thickness of the mucus layer;
•Mucus viscosity
•Molecular size of the drug—for THE binding molecules to mucus
glycoproteins via electrostatic interactions increase contact time
Alveolar clearance
The uptake of particles by alveolar macrophages is a fairly rapid
process clearance

9. The mucus not exist as a stagnant layer but is constantly being
propelled along the TB airways by the rhythmic beating of cilia
on epithelial cells,
Drug entrapped in the mucus will be removed from the TB region
via mucociliary clearance within a few hours after being deposited.
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Fig. Process of mucocillary clearance

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Area & Absorption barrier thicknes
The surface area of the airways is approximately 140 m2, greater
surface area the absorption of the drug.
•The lung receives 100% of the cardiac output via a network of fine
capillaries.
•This rich blood supply which promotes rapid gaseous
exchange is also beneficial for systemic drug delivery.
Blood Supply

11. Mechanism of Pulmonarydrug absorption
Drug
Transcellular
Transport
Lipophilic Drug
Absorbed
Paracellular
Transport
Hydrophilic Drug
Absorbed
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•low dose need due to targeted action because of that reduced
systemic side-effects
• Rapid onset of action;
• Avoidance of gastrointestinal upset;
• Avoidance of intestinal and hepatic first-pass metabolism.
•Nasal drug delivery is attractive not because it is BETTER than
injectable
•It used when a drug is poorly absorbed orally
e.g. Na cromoglicate.
Advantages

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•Various factors affect the reproducibility of drug delivery to the
lungs, including physiological and pharmaceutical (device,
formulation) variables.
•limited absorbtion due to physical barrier of the mucus layer
and the interactions of drugs with mucus.
•Mucociliary clearance reduces the retention time of drugs
within the lungs.
Disadvantages

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18. CURRENT TECHNOLOGIES FOR PULMONARY
DRUG DELIVERY
Currently there are three principal categories of aerosol generator employed
in inhalation therapy:
• Nebulizer;
• Pressurized metered-dose inhaler (pmdi);
• Dry powder inhaler (DPI).
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Nebulizer Definition :
Drug solution is drawn from the reservoir up the capillary as a
result of the region of negative pressure created by the
compressed air passing over the open end of the capillary (Venturi
effect).
Air jet Nebulizer

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These nebulizers rely on a transducer made from a piezo-electric
crystal which produces high frequency sound waves in the liquid.
The waves give rise to vertical capillaries of liquid (“fountains”)
which, when the amplitude of the energy applied is sufficient, break
up to provide an aerosol.
Ultrasonic Nebulizer

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•For successful delivery of drug particles into the lung requires that
particle size should be controlled to <5 μm
•The problems associated with particle size is to use a carrier particle
such as lactose. (usually 20–100 μm)
Spinhaler
Dry Powder Inhalers (DPIs)

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1. Container
2. Metering valve
3. An elastomer seal
4. The actuator
5. propellant
Pressurized Metered Dose Inhalation Devices

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32. PDDS used becouse of limition associsted with the conventional
treatment of verious chronic disease
In this DDS directly act to lung and get systemic and local effect
Modification in PDDS keep going on to modify release profile to
over come limitation associate Physicochemical barrier
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Conclusion

33. THANK YOU…
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