Lung as a target organ for chemical drug delivery system

2.  Because of limitations associated with the conventional
treatment of various diseases a growing attention has been
given to the development of targeted drug delivery systems.

3.  The efficacy of a treatment mostly depends on the
techniques by which the drug is delivered and optimum
concentration of the drug.
 The lung is capable of absorbing pharmaceuticals either for-
local deposition or for systemic delivery.

4.  There is mainly two types-
1. Intranasal administration
2. Oral inhalative administration
The latter is divided further into two subgroups-
a) Intratracheal instillation
b) Intratracheal inhalation

5.  Intratracheal instillation is most often used.
 In this method small amount of drug solution or dispersion is
delivered into the lungs by a special syringe.

7.  It is difficult to administer a formulation
through pulmonary route without suitable
drug delivery devices.
The drug delivery devices are given below.
1. Metered Dose Inhalers
2. Dry Powder Inhalers
3. Nebulizers:
Jet Nebulizers
Ultrasonic Nebulizers

8.  Spray drying technique (particle size is more
than 2µm)
 Spray freeze drying method
 Supercritical fluid technology
 Double emulsion technique
 Particle replication in non wetting templates
 Solvent precipitation method
 Micronization

9.  Drugs for pulmonary delivery require some carriers for
targeted action in lungs.
 Carriers may help in reducing the side effects also.
 The carrier systems used for pulmonary drug delivery are
given below.
1. Inert Carriers
2. Biodegradable Polymers
3. Microparticles
4. Nanoparticles
5. Liposomes

10. Drug Uses Carriers Method
Rifampicin Anti-
tuberculosis
Nanoparticles Solvent
evaporation
Isoniazid Anti-
tuberculosis
Nanoparticles Multiple
emulsion
technique
Tobramycin Antibiotics Nanoparticles Emulsion-based
spray-drying
Doxycycline
ciprofloxacin
Antibiotics Microparticles Spray-drying
Salbutamol
sulphate
Anti-asthmatic Microparticles Spray drying
Ketotifen
fumarate
Anti-
inflammatory
Liposomes Freeze drying

11.  Some chronic pulmonary diseases can be sufficiently treated
through pulmonary route of drug administration. e.g,
tuberculosis, insulin in diabetes mellitus by intratracheal
instillation and spray instillation.

12.  Improvement of efficiency, selectively and safety profile.
 Targeted disposition achieved easily
 Improve treatment outcomes of a variety of disease of
respiratory system
 Avoid first-pass metabolism
 Requires less amount of drug
 Reduced side effects

13. 60 - 90 % Swallowed
(reduced by spacer
or mouth rinsing)
Mouth and pharynx
GI tract
10 - 40 %
Deposited in lung
Lung
Complete absorption
from the lung
Systemic
Circulation
Systemic
side effects
Liver
Orally bioavailable
fraction
Absorption
from gut
First-pass
inactivation

14.  All kind of drugs can not be used
 Sometimes show toxicity
 Has a risk of drug deposition
 Some patients show sensivity
 Requires high cost drugs and instrument
 Improper dosing
 Difficulty in producing optimum particle size
 Stability problems

15.  The term kernicterus means damage to the brain centres of
infants caused by increased levels of unconjugated indirect
bilirubin which is free (not bound to albumin)
 Albumin content is low in newborn. As a result, the unbound
concentration of drug that primarily bind to albumin, for
example phenytoin and diazepam, is increased.

16.  Kernicterus in infants is an example of a disorder caused by
displacement of bilirubin from albumin binding sites by the
NSAIDs.

17.  Gronberg, Nickolaus, et al. Am as pathol. 2002;57:55-60.
[PubMed]
 Tancer DI, Witt C, et al. Controlled delivery of peptides and
proteins. 2000;44:54-68. [PubMed]
 Lipinski C. Poor aqueous solubility- An industry wide problem
in drug discovery. American Pharmaceutical Review, 2002, 5:
82-85.

18. THANK YOU