The document discusses pulmonary drug delivery systems (PDDS). It begins by describing the anatomy and physiology of the respiratory tract, then outlines some key advantages and disadvantages of PDDS. It discusses different approaches to PDDS including aerosols, metered dose inhalers, dry powder inhalers, and nebulizers. Factors affecting pulmonary drug delivery are enumerated. Applications include treatment of asthma, COPD, infections, and cancers of the lungs. In summary, PDDS provide targeted delivery to the lungs while avoiding first-pass metabolism.

1. By,
Mrs. Mali Vidhya Vijaykumar
Assistant Professor,
R. P. College of Pharmacy
Osmanabad

2.  Introduction.
 Anatomy and physiology of respiratory tract.
 Advantages of PDDS.
 Disadvantages of PDDS.
 Approaches of PDDS.
 Components of pulmonary formulations.
 Factors affecting Pulmonary drug delivery.
 Applications of Pulmonary Drug Delivery System.

3.  Respiratory tract is one of the oldest rout for drug
administration.
 Inhalation therapy is established itself is a valuable tool in the
local therapy of pulmonary diseases such as; asthma and
COPD.
 It is form of targeted drug delivery.
 Popularly marketed as inhalation aerosol products for local
effects
 The drugs used in Asthma and COPD :
◦ β antagonist : Salbutamol(albuterol), Terbutalin formoterol etc.
◦ Corticosteroids : Budesonide, Flixotide or Beclomethason etc.
◦ Mast cell stabilizers : Sodium cromoglycate or nedrocromi etc.

4.  Latest and most promising application of pulmonary drug
administration is,
 Achieve systemic absorption of drug.
 Particularly for the drugs with poor bioavailability such
as proteins and peptides, the respiratory tract might be
convenient port of entry .

6.  The human respiratory system is a complicated organ system of
very close structure-function relationship.
 The system consisted of two regions:
A. The conducting system
B. The respiratory region
 The airway is further divided into many folds:
Nasal cavity and associated sinuses, and the nasopharynx,
larynx, trachea, bronchi and bronchioles.
 The respiratory region consist of respiratory bronchioles,
alveolar ducts and alveolar sacs.

8.  The human respiratory tract is a branching system of air
channels with approximately 23 bifurcations from the mouth
to alveoli.
 The major task of the lungs is gas exchange, by adding oxygen
to and removing carbon-dioxide from the blood passing
through the pulmonary capillary bed.

10.  Primary function is to obtain oxygen for use by body's cells &
eliminate carbon dioxide that cells produce
 Includes respiratory airways leading into (& out of) lungs plus
the lungs themselves
 Pathway of air:
Nasal cavities (or oral cavity) > pharynx > trachea > primary
bronchi (right & left) > secondary bronchi > tertiary bronchi >
bronchioles > alveoli (site of gas exchange)

12. 1. It is needle free pulmonary delivery.
2. It requires low and fraction of oral dose.
3. Pulmonary drug delivery having very negligible side effects
since rest of body is not exposed to drug
4. Onset of action is very quick in pulmonary drug delivery.
5. Degradation of drug by liver is avoided in pulmonary drug
delivery.

13. 1. Stability of drug in-vivo.
2. Transport
3. Targeting specificity.
4. Drug irritation and toxicity.
5. Immunogenicity of proteins.
6. Drug retention and clearance.

14.  Low Efficiency of inhalation system
 Less drug mass per puff
 Poor formulation stability for drug
 Improper dosing reproducibility

16.  The drugs can be administered by pulmonary route utilizing two
techniques
◦ Aerosol inhalation
◦ Intra-tracheal instillation
 By applying aerosol technique, we could achieve more uniform
distribution with greater extent of penetration into the peripheral
or the alveolar region of the lung, but this costs more and also
faced with difficulty in measuring the exact dose inside the
lungs.
 In contrary to this, instillation process is much simple, not
expensive and has non-uniform distribution of drugs.

17.  Aerosol preparations are stable dispersion or suspensions of
solid material and liquid droplets in a gaseous medium.
The drugs, delivered by aerosols are deposited in the airway by;
Gravitational sedimentation
Inertial impaction and
Diffusion

18.  Mostly larger drug particles are deposited by first two
mechanisms in the airways, while the smaller particles get their
way into the peripheral region of the lungs by following
diffusion.
There are three commonly used aerosols:
1. Jet or ultrasonic nebulizers
2. Metered dose inhalers
3. Dry powder inhalers
 The basic function of these three completely different devices, is
to generate a drug containing aerosol cloud that contain the
highest possible fraction of particles in the desired size ranges.

19.  These are widely used as aerosolize drug solutions or suspensions
for drug delivery to the respiratory tract and are predominantly
useful for the treatment of hospitalized patients, delivered by the
drug in the form of mist.
 There are two basic types :
1. Air jet
2. Ultrasonic nebulizer

20. Compressed air is forced through an orifice,
an area of low pressure is formed where the
jet is exist.
A liquid may be withdrawn from a
perpendicular nozzle to mix with the air jet to
form driplets.
A baffel within the nebulizer is often used to
fecilitate the formation of the aerosol cloud.
Carrier gas (Oxygen) can be used to generate
the “Air Jet”.

21. Ultrasound waves are formed in an
ultrasonic nebulizer chamber by a ceramic
pieoelectric crystal that vibrate when
electrically excited.
These set up high energy waves in the
solution, within the device chamber, of a
precise frequency that generates an aerosol
cloud at the solution surface.

22. Jet nebulizer Ultrasonic nebulizer

23.  These are used in the treatment of diseases like asthma and
COPD.
 Can be given in the form of solution or suspension.
 The particle size less than 5 micron is observed here.
 This is used to minimize the number of administration errors.
Advantage: It can deliver a measured amount of drug or
medicament accurately.

25.  These are bolus drug delivery devices that contain solid drug in
the dry powder mix that fluidized when the patient inhales.
 These are typically formulated as one-phase, solid particle
blends.
 The drugs with particle size less than 5 µm is used.
 These are widely accepted inhalation delivery device,
particularly in Europe, where they are currently used by
approximately 40% of asthma patients.

27.  Single dose powder inhalers are devices in which a powder
containing capsule is placed in a holder.
 The capsule is opened into the device and the powder is
inhaled.
 This device is truly a metered dose inhaler powder delivery
system.
 The drug is contained in a storage reservoir and can be
dispensed into the dosing chamber by a simple back and forth
twisting action on the base of the unit.

29.  The pulmonary route is one of the preferred drug delivery routes,
since it provides a large surface area for rapid absorption.
 The therapeutic advantages of selective targeting of drugs to the
airways and lungs for the treatment of respiratory diseases.
 Because of the large surface area and rich blood supply, the
pulmonary airway enables rapid onset of therapeutic action even with
reduced doses compared to the oral and other systemic routes.
 therefore, systemic side effects are minimal.

30.  For the treatment of asthma.
 Treatment of Pulmonary infections.
 For Chronic Obstructive Pulmonary Diseases
 Deposition of cardiovascular agent.
 Blood glucose modification.
 Treatment of Lungs cancer.
 Treatment of cystic fibrosis.

32. 1. Write a note on Pulmonary drug delivery system.
2. Give the advantages and disadvantages of Pulmonary drug
delivery system.
3. Give the anatomy of respiratory system.
4. Enlist different approaches to Pulmonary drug delivery
system.
5. Define Aerosols. Enlist and explain one type of Aerosols used
in Pulmonary drug delivery system.
6. Write a note on Metered Dose Inhalers.
7. Explain What are Dry Powder Inhalers.
8. Enumerate on the Nebulizers and its types.
9. Enlist factors affecting pulmonary drug deliver.
10. Write down applications of Pulmonary drug delivery system.