This document provides an overview of targeted drug delivery systems. It defines targeted drug delivery as selectively delivering medication only to the intended site of action. The document outlines the need for drug targeting to increase efficacy and reduce side effects. It describes ideal characteristics of targeted systems and different strategies for targeting, including passive, active, inverse, and dual targeting. Various types of targeted delivery systems are mentioned, such as liposomes, niosomes, dendrimers, and hydrogels. The document provides advantages of targeted systems and references further resources on the topic.

1. CSJM UNIVERSITY KANPUR
UNIVERSITY INSTITUTE OF PHARMACY
Targeted drug delivery
system
PRESENTED BY -
RAGHVENDRA KUMAR YADAV
M.PHARM 1ST YEAR
(PHARMACEUTICS)
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2. CONTENT
 Introduction
 Ideal characteristics
 Advantages
 Disadvantages
 Carrier or markers
 Strategies of targeting
 Types of targeted drug delivery system
 References
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3. INTRODUCTION
‘Targeted drug delivery system is a special form of drug
delivery system where the medicament is selectively targeted
or delivered only to its site of action or absorption and not to
the non-target organs or tissues or cells.’
• It is a method of delivering medication to a patient in a
manner that increases the concentration of the medication in
some parts of the body relative to others.
• Targeted drug delivery seeks to concentrate the medication in
the tissues of interest while reducing the relative
concentration of the medication in the remaining tissues.
• This improves efficacy and reduce side effects.
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4. NEED FOR DRUG TARGETING :
• In the treatment or prevention of diseases.
• Pharmaceutical drug instability in conventional dosage form
solubility ,biopharmaceutical low absorption, high membrane
bounding, biological instability, pharmacokinetic/
pharmacodynamic short half life, large volume of distribution,
low specificity, clinical, low therapeutic index.
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5. IDEAL CHARACTERISTICS :
• It should be nontoxic, biocompatible, biodegradable, and
physicochemical stable in vivo and in vitro.
• Restrict drug distribution to target cells or tissues or
organs and should have uniform capillary distribution.
• Controllable and predicate rate of drug release.
• Drug release does not effect the drug action.
• Therapeutic amount of drug release.
• Minimal drug leakage during transit.
• Carriers used must be bio-degradable or readily
eliminated from the body without any problem and no
carrier induced modulation of diseased state.
• The preparation of the delivery system should be easy or
reasonably simple, reproductive and cost effective.
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6. ADVANTAGES
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7. DISADVANTAGES
• Rapid clearance of targeted systems.
• Immune reactions against intravenous administered carrier
systems.
• Insufficient localization of targeted systems into tumour cells.
• Diffusion and redistribution of released drugs.
• Requires highly sophisticated technology for the formulation.
• Requires skill for manufacturing storage, administration.
• Drug deposition at the target site may produce toxicity
symptoms.
•Difficult to maintain stability of dosage form. E.g.: Resealed
erythrocytes have to be stored at 40 C.
• Drug loading is usually law. E.g. As in micelles. Therefore it
is difficult to predict /fix the dosage regimen.
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8. CARRIER OR MARKERS :
• Targeted drug delivery can be achieved by using carrier system.
• Carrier is one of the special molecule or system essentially
required for effective transportation of loaded drug up to the
pre selected sites.
• They are engineered vectors, which retain drug inside or into
them either via encapsulation and/ or via spacer moiety and
transport or deliver it into vicinity of target cell.
Pharmaceutical carriers :
 Polymers
 Microcapsules
 Microparticles
 Lipoproteins
 Liposomes
 Micelles
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9. STRATEGIES OF DRUG TARGETING
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10. PASSIVE TARGETING
 This is based on the accumulation of drug at areas around
the site of interest, such as in case of tumor tissues. This is
called Enhanced Permeability Retention (EPR) effect.
 Although the EPR effect applies for nanoparticle
administered, the majority (>95%) of these nanoparticles
tend to accumulate in organs other than those of interest
such as liver, lungs and spleen.
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11. ACTIVE TARGETING
 Through the use of ligand-receptor interactions, active
targeting describes the drug targeting interactions.
 The currently available drug delivery systems are able to
reach the target by the virtue of blood circulation and
extravasation.
Types
 First order targeting (organ compartmentalization).
 Second order targeting (cellular targeting).
 Third order targeting (intracellular targeting).
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13. INVERSE TARGETING
• In this type of targeting attempts are made to avoid passive
uptake of colloidal carrier by RES (Reticular Endothelial
Systems) and hence the process is referred to as inverse
targeting.
• To achieve inverse targeting, RES normal function is
suppressed by pre injecting large amount of blank colloidal
carriers or macromolecules like dextran sulphate
• This approach leads to saturation of RES and suppression of
defence mechanism. This type of targeting is a effective
approach to target drug(s) to non-RES organs.
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14. Dual Targeting :
• In this targeting approach carrier molecule itself have their own
therapeutic activity and thus increase the therapeutic effect of
drug.
• For example, a carrier molecule having its own antiviral activity
can be loaded with antiviral drug and the net synergistic effect
of drug conjugate was observed.
Double Targeting :
• Temporal and spatial methodologies are combined to target a
carrier system, then targeting may be called double targeting.
• Spatial placement relates to targeting drugs to specific organs,
tissues, cells or even subcellular compartment. whereas
temporal delivery refers to controlling the rate of drug delivery
to target site.
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15. TYPES OF TARGETED DRUG
DELIVERY SYSTEM
Nano Tubes : They are hollow cylinder made of carbon,
atoms which can be filled and sealed for potential drug
delivery.
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16. Liposomes : Liposomes are simple microscopic vesicles in
which an aqueous volume is entirely composed by membrane of
lipid molecule various amphiphelic molecules have been used to
form liposomes. The drug molecules can either be encapsulated
in aqueous space or intercalated into the lipid bilayers The
extent of location of drug will depend upon its physicochemical
characteristics and composition of lipids.
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17. Niosomes : Niosomes are nonionic surfactant vesicles which
can entrap both hydrophilic and lipophilic drugs either in
aqueous phase or in vesicular membrane made up of lipid
materials It is reported to attain better stability than
liposome’s. It may prove very useful for targeting the drugs
for treating cancer, parasitic, viral and other microbial
disease more effectively.
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18. Dendrimers : Dendrimers are synthetic, unimolecular,
branched nanostructures They are made up of layers of
polymer surrounding a control core. The dendrimers surface
contains many different sites to which drugs may be attach.
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19. Virosomes : Virosomes are immuno modulating liposomes
consisting of surface glycoprotein of influenza virus
(immune stimulating reconstituted influenza virosome)
muramyl dipeptide etc. Virosomes must be target oriented
and their fusogenic characteristics could be exploited in
genome grafting and cellular micro injection.
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21. Hydrogels: Hydrogels are three-dimensional, polymeric
cross linked Hydrogel nano particles, known as “nano gels”
are fast emerging as a favourable method of nano
particulate drug delivery systems. Drug loading into the gel
matrix is possible due to the highly porous structure. Drug
loading and the efficacy of entrapping drug are largely
dependent on the drug solubility in the matrix.
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22. ADVANTAGES
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23. REFERENCES
1. Gupta M, and Sharma V, “Targeted drug delivery system: A review,”
Research Journal of Chemical Sciences, vol. 1, 2011.
2. Pudota S.K, Shirisha V, and Kumar R.H, “A review on drug targeting and
drug carriers,” Internatonal Journal of Research in Pharmaceutical and
Nano Sciences, vol. 2, 2013.
3. Bae Y.H and Park K, “Targeted drug delivery to tumors: Myths, reality and
possibility,” Journal of Controlled Release, vol. 153, 2011.
4. Madaan K, “Dendrimers in drug delivery and targeting: Drug-dendrimer
interactions and toxicity issues,” Journal of Pharmacy and Bioallied
Sciences, vol. 6, 2014.
5. Jain N.K., “Advance In Controlled & Novel Drug Delivery” CBS
Publication First Edition 1997
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