The document discusses pulmonary drug delivery systems focusing on their benefits, technologies, and challenges. Pulmonary delivery is advantageous in targeted treatment of respiratory diseases, offering rapid effects and minimizing systemic side effects, but faces issues like low efficiency and formulation stability. Various aerosol types, inhalation devices, and methods for evaluating drug delivery effectiveness are also reviewed.

1. PULMONARY DRUG DELIVERY SYSTEM
Presented By
Sujitha Mary
M Pharm
St Joseph College Of Pharmacy
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2. CONTENT
 Introduction
 Anatomy and physiology of lungs
 Advantage and disadvantage of Pulmonary Drug
Delivery system.
 Aerosols , propellants & container types.
 Current technologies for pulmonary drug delivery.
 New technologies for pulmonary drug delivery.
 Evaluation of Pharmaceutical Aerosols & PDDS.
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3. INTRODUCTION
 Pulmonary drug delivery is primarily used to
treat conditions of the airways, delivering
locally acting drugs directly to their site of
action.
 Delivery of anti-asthmatic and other locally
acting drugs directly to their site of action
reduces the dose needed to produce a
pharmacological effect, while the low
concentrations in the systemic circulation may
also reduce side-effects.
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4.  The drugs which are administered by pulmonary route
are not only for lungs delivery but it goes to systemic
circulation and produce the effect where it is desired
through out the body. For Eg. A product containing
ergotamine tartrate is available as an aerosolized
dosage inhaler for the treatment of migraine &
Volatile anesthetics, including, halothane, are also
given via the pulmonary route.
 In recent years, the possibility of utilizing the
pulmonary route for the systemic delivery of peptides
and other molecules which are not absorbed through
the gastrointestinal tract has also been explored.
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5. Anatomy & Physiology of Lungs
Lungs region
Nasopharyngeal region
Tracheo-bronchial region
Alveolar region
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6. 6

7. 1)Lung regions
The respiratory tract starts at the nose and terminates deep in
the lung at an alveolar sac. There are a number of schemes
for categorizing the various regions of therespiratory tract.
2) Nasopharyngeal region (NP region)
This is also referred to as the “upper airways”, which involves
the respiratory airways from the nose down to the larynx.
3) Tracheo-bronchial region (TB region)
This is also referred to as the “central” or “conducting airways”,
which starts at the larynx and extends via the trachea,
bronchi, and bronchioles and ends at the terminal
bronchioli.
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8. 4) Alveolar region
This is also referred to as the “respiratory airways”,
“peripheral airways” or “pulmonary region”,
Comprising the respiratory bronchioles, alveolar
ducts and alveoli .
Drugs administered by inhalation for local action in the airways. COPD=chronic obstructive
pulmonary disease
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9. Advantage of PDDS
 Inhaled drug delivery puts drug where it is needed.
 It requires low and fraction of oral dose i.e. drug content of
one 4 mg tablet of salbutamol equals to 40 doses of meter
doses.
 Pulmonary drug delivery having very negligible side effects
since rest of body is not exposed to drug.
 Onset of action is very quick with pulmonary drug delivery.
 Degradation of drug by liver is avoided in pulmonary drug
delivery.
 In asthma and diabetes requires long term treatment if it is
given by pulmonary drug delivery safety is maximum because
rest of body is not exposed to drug.
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10. Disadvantage of PDDS
 Low Efficiency of inhalation system
 Poor formulation stability for drug
 Improper dosing reproducibility
10

11. Aerosols
 Aerosol is a pressurized dosage forms
containing one or more therapeutic active
ingredients which upon actuation emit a fine
dispersion of liquid and/or solid materials in a
gaseous medium.
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12. COMPONENTS OF AEROSOLS
1. Propellant
2. Container
3. Valve and actuator
4. Product concentrate
12

13. PROPELLANTS
 Responsible for developing proper pressure
within the container.
 Provide driving force to expel the product from
the container.
TYPES OF PROPELLANTS
(a) Liquefied gases Propellants
(b) Compressed gases Propellants
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14. PROPELLANTS TYPES
 Depending on the route of administration and use,
I) Type-I Propellant A- Liquefied Gas
1) For oral and inhalation (Fluorinated hydrocarbons)
• Tri-chloro-mono-flouro methane (propellant 11)
• Di-chloro di-fluro methane (propellant 12)
2) Topical Pharmaceutical aerosols (Hydrocarbons)
• Propane
• Butane
II) Type-II Propellant B - Compressed Gas Propellants
1)Compound gases
• Nitrogen
• Carbon di-oxide
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15. LIQUEFIED GAS PROPELLANTS
 Exist as liquids under pressure.
 Because the aerosol is under pressure
propellant exists mainly as a liquid, but it will
also be in the head space as a gas.
 The product is used up as the valve is opened,
some of the liquid propellant turns to gas and
keeps the head space full of gas.
 In this way the pressure in the can remains
essentially constant and the spray
performance is maintained.
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16. CHLORO FLUORO CARBONS
Advantages
• Chemical inertness
• Lack of toxicity
• Non flammability.
• Lack of explosiveness.
Disadvantages
• High cost
• It depletes the ozone layer
Examples:
Trichloromonofluoromethane – Propellant 11
Dichlorodifluoromethane - Propellant 12
Dichlorotetrafluoroethane - Propellant 114
• Propellant of choice for oral and inhalation .
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17. HYDROCARBONS
• Can be used for water based aerosols and topical use
Advantages
• Inexpensive
• Excellent solvents
• It does not cause ozone
Example
Propane - Propellant A-108
Isobutane - Propellant A-31
Butane - Propellant A-17
Disadvantages
• Inflammable
• Unknown toxicity
produced
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18. HYDROFLUORO CARBONS AND HYDRO CHLORO
FLUORO CARBONS
 These compounds break down in the atmosphere at faster rate than cfcs.
 Lower ozone destroying effect
Advantages:
 Low inhalation toxicity
 High chemical stability
 High purity
 Not ozone depleting
Disadvantages
 Poor solvent
 High cost
EXAMPLES:
HEPTAFLUORO PROPANE (HFA-227) TETRAFLUOROETHANE (HFA-134A)
DIFLUOROETHANE - PROPELLANT 152A
CHLORODIFLUOROMETHANE - PROPELLANT 22
CHLORODIFLUOROETHANE - PROPELLANT 142 B
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19. COMPRESSED GAS PROPELLANTS
 Compressed gas propellants occupy the head space above
the liquid in the can.
 When the aerosol valve is opened the gas 'pushes' the liquid
out of the can
 The amount of gas in the headspace remains the same but it
has more space, and as a result the pressure will drop during
the life of the can
 Spray performance is maintained however by careful choice
of the aerosol valve and actuator
 Examples:
Carbon dioxide
Nitrous oxide
Nitrogen..
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20. CONTAINERS
 They must be able to withstand pressures as high
as 140 to 180 psig (pounds per sq. inch gauge) at
130 ° F.
AEROSOL CONTAINERS
A.Metals
i. Tinplated steel
ii. Aluminum
iii. Stainless steel
B. Glass
I. Uncoated glass
II. Plastic coated glass
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21. TIN PLATED STEEL
CONTAINERS
 It consist of a sheet of steel plate, this sheet is coated
with tin by electrolytic process .
 The coated sheet is cut into three pieces ( top ,
bottom and body
 The top, bottom are attached to body by soldering.
 When required it is coated with organic material
usually oleoresin, phenolic , vinyl or epoxy coating.
 Welding eliminates soldering process, Saves
considerable manufacturing time and decreases the
product/container interaction.
 Recent developments in welding include Soudronic
system and Conoweld system.
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22. ALUMINIUM CONTAINERS
 Used for inhalation and topical aerosols .
 Manufactured by impact extrusion process.
 Light in weight, less fragile, Less incompatibility
due to its seamless nature
 Greater resistance to corrosion .
 Pure water and pure ethanol cause corrosion to Al
containers
 Added resistance can be obtained by coating
inside of the container with organic coating like
phenolic , vinyl or epoxy and polyamide resins..
22

23. STAINLESS STEEL CONTAINERS
 Used for inhalation aerosols
Advantage :
 Resistant to many materials.
 Extremely Strong.
Disadvantage :
 Costly
 No need for internal coating. ◦
23

24. GLASS CONTAINERS
 These containers are preferred because of its
Aesthetic value and absence of incompatibilities.
 These containers are limited to the products having a
lower pressure (33 psig) and lower percentage of the
propellant.
 Used for topical and MDI aerosols. .
Two types of glass aerosol containers
 Uncoated glass container: Less cost and high clarity
and contents can be viewed at all times
 Plastic coated glass containers: These are
protected by plastic coating that prevents the glass
from shattering in the event of breakage.
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25. VALVES
 To delivered the drug in desired form.
 To give proper amount of medication.
 Not differ from valve to valve of medication in
pharmaceutical preparation.
Types
 Continuous spray valve
 High speed production technique.
 Metering valves
 Dispersing of potent medication at proper dispersion/
spray approximately 50 to 150 mg ±10 % of liquid
materials at one time use of same valve.
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26. Valve components
Ferrul or mount cap
 Valve body or housing
 Stem
 Gasket
 Spring
 Dip tube
26

27. ACTUATORS
 These are specially designed buttons which
helps in delivering the drug in desired form i.e.,
spray, wet stream, foam or solid stream.
TYPES OF ACTUATORS:
 Spray actuators
 Foam actuators
 Solid steam actuators
 Special actuators
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28. SPRAY ACTUATORS:
 It can be used for topical preparation, such as antiseptics, local
anesthetics and spray on bandages etc.
 It allows the stream of product concentrate and propellant to pass
through various openings and dispense as spray. ◦
FOAM ACTUATORS:
 It consist of large orifice which ranges from 0.070—0.125 inch.
SOLID STREAM ACTUATORS:
 These actuators are required for dispensing semi solid products
such as ointments .
SPECIAL ACTUATORS:
 These are used for a specific purpose.
 It delivers the medicament to the appropriate site of action such as
throat, nose, dental and eyes etc.
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29. RECENT ADVANCES IN PULMONARY DRUG
DELIVERY DEVICES
Following types of inhalation devices are present
1. Inhalation drug delivery system by ‐ nebulizer
2. Inhalation drug delivery system by - metered
dose inhalers
3. Inhalation drug delivery system by ‐ dry
powder inhalers
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30. 1. Nebulizer
 Nebulizers used today for drug delivery to the respiratory tract and
are particularly useful for the treatment of hospitalized or
nonambulatory patients. Mainly there are two general types of
nebulizer systems,
i. The ultrasonic and
ii. The air jet
 The ultrasonic nebulizer uses a piezoelectric crystal, vibrating at a
high frequency (usually 1–3 MHz), to generate a fountain of liquid in
the nebulizer chamber; the higher the frequency, the smaller the
droplets produced
 The jet nebulizer functions by the Bernoulli principle by which
compressed gas (air or oxygen) passes through a narrow orifice,
creating an area of low pressure at the outlet of the adjacent liquid
feed tube. This results in the drug solution being drawn up from the
fluid reservoir and shattering into droplets in the gas stream.
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31. 31

32. Advantage:
 Avoidance of metabolism by the gastrointestinal tract.
 Avoidance of liver first pass metabolism.
 Rapid absorption, higher bioavailability, therefore, lower
doses .
 The treatment of acute asthma in an emergency care unit.
 The nebulizer can transport more drugs to the lungs than
MDI or DPI.
Disadvantage:
 The need for higher drug doses to achieve a therapeutic
result
 Higher costs
 Lack of possibility
32

33. Metered Dose Inhaler (MDI)
 Used for the treatment of
respiratory diseases such as
asthma and COPD.
 They can be given in the form
of suspension or solution.
 Particle size of less than 5
micros
 It can be delivery measure
amount of medicament
accurately.
 Used to minimize the number
of administrations errors.
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34. Advantage of MDI
Usually inexpensive as compare to dry powder inhalers
and nebulizers.
Small size and covenience.
It delivers specified amount of dose.
Quick to use.
Disadvantage of MDI
Accurate co-ordination between actuation of a dose and
inhalation is essential Continued…
There is no information about the number of dose left in
the MDI
Difficult to delivery high doses.
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35. 35

36. 36

37. Dry Powder inhaler (DPI)
 DPIs are bolus drug delivery devices that contain solid
drug in a dry powder mix (DPI) that is fluidized when
the patient inhales.
 DPIs are typically formulated as one-phase, solid
particle blends. The drug with particle size of less than
5µm is used.
 Dry powder formulations either contain the active drug
alone or have a carrier powder (e.g. lactose) mixed
with drug to increase flow properties of drug.
 DPIs are a widely accepted inhaled delivery dosage
form, particularly in Europe., where they are currently
used by approximately 40% of asthma patients.
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38. Advantage
 Less formulation problem
 Less need for patient co-ordination.
 Propellant-free.
Disadvantage
 Not available worldwide
 More expensive than pressurized metered dose inhalers.
 Greater potential problems in dose uniformity.
 Device resistance and other design issues.
 Delivery on patient’s inspiratory flow rate and profile.
 Dry powders are at a lower energy state, which reduces the
rate of chemical degradtion
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39. Today there are essentially two types of
DPIs
Unit-Dose Devices
 Single dose powder inhalers are device in which a
powder containing capsule is placed I a holder.
The capsule is opened with in the device and the
power is inhaled.
Multi dose Device
 This device is truly a metered-dose powder
delivery system. The drug is contained with 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
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40. 40

41. Evaluation of PDDS
 Intranasal administration
 Direct intratracheal administration
 Head only or nose only exposure system
 Whole body exposure system
 Passive Inhalation
 Air-Interface culture
 Primary cell culture
 Continuous cell cultures
 In- vivo
 In- vitro
 Cascade impactors
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42. Cascade impactors
 Cascade impactors operate on the principle of inertial impaction.
 Each stage of the impactor comprises a series of nozzles or jets
through which the sample laden air is drawn, directing any airborne
towards the surface of the collection plate for that particular stage.
 Whether a particular particle impacts on that stage is dependent on
its aerodyanamic diameter
 particle having sufficient inertia will impact on that particular stage
collection plate, whilst smaller particle will remain entrained in the
air stream and pass to the next stage where the process is
repeated.
 The stage are normally assembled in a stock or row in order of
decreasing particle size.
 As the jets get smaller, the air velocity increases such that smaller
particles are collected.
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43.  At the end of the test, the particle mass relating to each stage is
recovered using a suitable solvent and then analysed usually using
HPLC to determine the amount of drug actually present.
 The Ansdersen Cascade impactor (ACI) is most commonly used
impactor with in the pharma indusrty for the testing of inhaled
products.
 The ACI is an 8-stage cascade impactor suitable for measuring the
aerodynamic particle size distribution (APSD) of both MDIs and
DPIs
 This is also used to measure parameters like Fine Particle
Fraction(FPF) and mass median aerodynamic diameter(MMAD)
Limitation
 Measurement in cascade impactors are done at room temperature
and at low relative humidity which is not representative of human
airways ambient conditions.
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44. 44

45. In vitro
 In vitro model is used in this method
 It is significant that epithelial cells form a tense
monolayer in order to characterize the natural
epithelial barrier
 Monolayer tension and reliability are classically
assessed by measuring Tran’s epithelial electrical
resistance (TEER) and potential difference
crosswise the monolayer.
 Monolayers of lung epithelial cells permit the
categorization of drug transport and evaluation of
potential drug and formulation toxicity.
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46. In vivo
 Animal study is carried out to get information on drug
deposition, metabolism, absorption and kinetic profile as well
as drug and formulation tolerability
 Non-human primates are use only in advanced research
 By contrast, small rodents (mice, models for preliminary
studies on pulmonary drug delivery
 Human branching is symmetric, in contrast monopodial
branching of non human primates mammals
 Large mammals have longer airways than small rodents
 Different mucociliary clearance.
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47. Continuous cell cultures
 Continuous cell cultures are supplementary
reproducible and easier to utilize than primary cell
cultures but they frequently do not have the
differentiated morphology and the biochemical
characteristics of the original tissue
 There are a small number of cell lines resulting
from alveolar epithelial cells.
 A549 is a type II alveolar epithelial cell line that
originates from human lung adenocarcinoma.
 It can be very helpful in metabolic and
toxicological studies
47

48. Air-interface cultures
 Air-interface cultures (AIC) are models that permit
aerosol particles to place straight onto semi-dry
apical cell surface.
 Drug deposition and dissolution take place in a
small volume of cell lining fluid, a circumstances
that mimics more directly deposition on the lung
surface invivo
 The AIC show greater similarity to airways
epithelial morphology, with superior glycoprotein
discharge, more prominent microvilli
48

49. Passive inhalation
 During passive inhalation of aerosolised drugs,
animals are kept awake and allowed to breathe
normally
 The devices most frequently used for generating
aerosols are nebulisers.
 Passive inhalation is principally used in the mouse
and less frequently in larger animals (rat, guinea-
pig, dog ).
 The drug concentration in the aerosol is
determined by sampling the test atmosphere and
quantifying the drug in the sample.
49

50. Whole body exposure system
 In whole body aerosol exposure system,
animals are placed in a sealed plastic box that
is connected to a nebuliser or a generator of
dry powder aerosol
 There is potential drug absorption across the
skin after deposition on the animal fur,from the
nasal mucosa and from the gastrointestinal
tract.
50

51. Head-only or nose-only exposure systems
 In the head-only or nose-only exposure
systems, the animal is attached to the
exposure chamber and only the head or the
nose is in contact with the aerosol.
 The systems can be designed for delivering
drugs to one or to several animals
 Compared with the whole body exposure
system, the head-only or nose-only exposure
systems offer several advantages
51

52. 52

53. Direct intratracheal administration
 Dry powders can be delivered intratracheally
using a powder- insufflator or by generating a
powder aerosol.
 It is done to measure drug deposition and
systemic drug absorption
 Advantages of intratracheal administration of
drugs include the perfect control of the drug dose
delivered, the absence of drug losses in the
instrumentation (except for liquid and powder
aerosols), the bypassing of nasal passages
53

54. 54

55. Intranasal administration
 Intranasal administration is mostly known for
local drug delivery to the nasal mucosa but it
can also be used for intrapulmonary drug
administration in mice.
 Intranasal administration is performed on the
anaesthetized mouse kept in a vertical
position.
 With the help of a micropipette, the solution is
deposited on a nostril and is simply aspirated
in respiratory airways during breathing.
55

56. 56

57. APPLICATION
In migraine
 Ergotamine via metered dose inhaler was used
successfully to treat migraine headache
New use of pulmonary delivery in diabetes .
 Insulin inhalers would work much like asthma
 The products fall into two main groups the dry
powder formulations and solution, which are
delivered through different patented inhaler
systemsinhalers.
 E.g. Novel pMDI formulations for pulmonary
delivery of proteins
57

58. Application of pulmonary drug delivery in cancer
chemotherapy
 Interleukin-2 stimulates immune function in cancer patients,
but injections cause fever, malaise, and local swelling
 Aerosol delivery of the anticancer agent’s difluoro methyl
ornithine and 5-fluorouracil reduced lung tumors in mice 50
%and 60 %, respectively.
 Inhaled chemotherapy seems a logical approach to treat lung
cancer
Diagnostic application pulmonary drug delivery
 Pulmonary drug delivery is not only useful for therapeutic
purpose but also for diagnosis purpose.
 example, inhalation of aerosols of methacholine and
histamine is responsiveness in asthma.
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