(M.PHARM. Pharmaceutics) 2nd Semester MOLECULARPHARMACEUTICS –MPH201T

1. (M.PHARM. Pharmaceutics) 2nd Semester
MOLECULAR PHARMACEUTICS – MPH 201 T
Targeting Methods:
Introduction preparation and evaluation,
Nano Particles & Liposomes:
Types, preparation and evaluation
By
SURYAKANT VERMA
Assistant Professor,
Department of Pharmaceutics,

2. CONTENTS
1. Targeting methods
• Introduction
2. Nanoparticles
• Types
• Preparation
• Evaluation
3. Liposomes
• Preparation
• Evaluation
• Applications

3. TARGETING METHODS:-
A special form of drug delivery system where the pharmacologically
active agent or 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.
Targeted drug delivery implies for selective and effective
localization of pharmacologically active moiety at pre identified
(preselected) target in therapeutic concentration, while restricting
its access to non-target normal cellular linings, thus minimizing
toxic effects and maximizing therapeutic index.
INTRODUCTION

4. •Targeting of drugs also help us to bypass first pass metabolism so a
drug can be administered in a form such that it reaches the receptor
sites in sufficient concentration without disturbing in extraneous
tissue cells.
•Targeted drug delivery system should be- biochemically inert (non-
toxic), non- immunogenic.
•Both physically and chemically stable in vivo and in vitro.
•Restrict drug distribution to target cells or tissues or organs and
should have uniform capillary distribution.
•Controllable and predictable rate of drug release.
•Should have therapeutic amount of drug release.
•Should have minimal drug leakage during transit.
•Carriers used should be bio-degradable or readily eliminated from
the body without any problem.
•The preparation of the delivery system should be easy or reasonably
simple, reproductive and cost effective.
CHARACTERISTICS

5. ADVANTAGES
DIS ADVANTAGES
• 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.
• Drug administration protocols may be simplified.
• Drug quantity may be greatly reduced as well as the cost of
therapy.
• Drug concentration in the required sites can be sharply
increased without negative effects on non-target compartments.

6. 1)Passive Targeting
2)Active Targeting
3)Inverse Targeting
4)Ligand Mediated Targeting
5)Physical Targeting
6)Dual Targeting
7)Double Targeting
STRATEGIES OF DRUG TARGETING

7. 1) Passive Targeting :-
•Drug delivery systems which are targeted to systemic circulation are
characterized as Passive delivery systems.
•In this technique drug targeting occurs because of the body’s natural response
to physicochemical characteristics of the drug or drug carrier system.
2) Active Targeting:-
In this approach carrier system bearing drug reaches to specific site on the
basis of modification made on its surface rather than natural uptake by RES.
• Surface modification technique include coating of surface with either a
bioadhesive, nonionic surfactant or specific cell or tissue antibodies (i.e.
monoclonal antibodies) or by albumin protein.
There are 3 Types of Active Targeting
1. First order targeting (organ compartmentalization).
2. Second order targeting (cellular targeting).
3. Third order targeting (intracellular targeting).
STRATEGIES OF DRUG TARGETING

8. STRATEGIES OF DRUG TARGETING
3) Inverse Targeting :-
•In this type of targeting attempts are made to avoid passive uptake
of colloidal carrier by RES (Reticulo 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.
4)Ligand Mediated Targeting :-
Achieved using specific mechanisms such as receptor dependent
uptake of natural LDL particles and synthetic lipid microemulsions
of partially reconstituted LDL particles coated with the apoproteins.

9. STRATEGIES OF DRUG TARGETING
5)Physical Targeting :-
•In this type of targeting some characteristics of environment changes like pH,
temperature, light intensity, electric field, ionic strength small and even specific
stimuli like glucose concentration are used to localize the drug carrier to
predetermined site.
•This approach was found exceptional for tumour targeting as well as cytosolic
delivery of entrapped drug or genetic material.
6) Dual Targeting :-
•In this targeting approach carrier molecule itself have their own therapeutic
activity and thus increasethe 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.
7) 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.

10. •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 onto
them either via encapsulation and/ or via spacermoiety and
transport or deliver it into vicinity of target cell.
Pharmaceutical carriers :
Polymers
Microcapsules
Microparticles
Lipoproteins
Liposomes
Micelles
Nanoparticles
CARRIER OR MARKERS

11. NANOPARTICLES

12. INTRODUCTION
 The prefix nano comes from the ancient Greek vavoc through
the Latin nanus meaning very small.
 Nanoparticles are defined as particulate dispersions or solid
particles with a size in the range of 10-1000nm.
 The drug dissolved, entrapped, encapsulated or attached to a
nanoparticle matrix.
 The term nanoparticle is a
combined name for both
nanospheres and
nanocapsules.
 Drug is confined to a cavity surrounded by a unique polymer
membrane called nanocapsules, while nanospheres are
matrix systems in which the drug is physically and uniformly
dispersed.

13. NANOPARTICLES
 NANOCAPSULES-
The nanocapsules are
system in which the
drug is confined to a
cavity surrounded by
a unique polymer
membrane.
 NANOSPHERES-
The nanospheres are
matrix systems in
which the drug is
physically and
uniformly dispersed.

14. IDEAL PROPERTIES OF NANOPARTICLES
NECESSARY FOR DRUG DELIVERY
Stable in blood
Nontoxic
Non-thrombogenic
Non-
inflammatory
Non-immunogenic
Biodegradable

15. ADVANTAGES OF NANOPARTICLES
Fairly easy preparation
Good protection
of the
encapsulated drug
Increased
therapeutic
efficacy
Targeted and drug
delivery
Retention of drug
at the active site
Increased
bioavailability
Good control over size
and size distribution
Longer clearance
time
Dose
proportionality

16. ADVANTAGES OF NANOPARTICLES
• Nanoparticles have many significant advantage over conventional and traditional
drug delivery system.
• Nanoparticles are control and sustain release form at the site of localization,
they alter organ distribution of drug compound. They enhance drug circulation in
blood, bioavailability, therapeutic efficacy and reduce side effects.
• Nanoparticles can be administer by various routes including oral, nasal,
parenteral, intra-ocular etc.
• In the tiny areas of body nanoparticles shows better drug delivery as compare to
other dosage form and target to a particular cell type or receptor.
• Nanoparticle enhance the aqueous solubility of poorly soluble drug, which
improves bioavailability of drug.
• As a targeted drug carrier nanoparticles reduce drug toxicity and enhance
efficient drug distribution.
• Useful to diagnose various diseases.
• Enhanced stability of ingredients.

17. DISADVANTAGES OF NANOPARTICLES
Limited targeting
abilities
Discontinuation of
therapy is not possible
Toxicity
Disturbance of
Autonomic
imbalance
Cytotoxicity

18. NANOMEDICINES FOR DRUG DELIVERY

19. S.NO TYPES OF
NANOPARTICLE
MATERIALS UED APPLICATION
1
Nanosuspensions
and Nanocrystals
Drug powder is
disperse d in
surfactant solution
Stable system for
controlled delivery of
poorly soluble drug
2 Solid lipid Nanoparticles
Melted lipid
dispersed in
Aqueous surfactant
Least toxic and more
stable
Colloidal carrier systems as
alternative materials To
polymers
3 Polymeric nanoparticles Biodegradable polymer
Controlled and targeted
drug delivery
4 Polymeric micelles
Amphiphilic
block co
polymers
Controlled and systemic
Delivery of water insoluble
Drugs
5 Magnetic Nanoparticles Magnetite Fe2O3,Meghe
Mite coated with dextran
Drug targeting
diagnostics
to in medicine
6 Carbon Nanotubes Metals ,semiconductors Gene and DNA delivery

20. ROUTES

21. POLYMER USED IN PREPARTION
Natural
Hydrophilic
PROTEINS
POL
YSACCHARIDES
Synthetic
Hydrophobic
PRE-
POLYMERIZED
POLYMERIZED IN
PROCESS

22. NATURAL HYDROPHILIC POLYMER
PROTEINS POLYSACCHARIDES
Gelatin Alginates
Albumin Dextran
Lectins Chitosan
Legumin Agarose
Vicilin Pullulan

23. SYNTHETIC HYDROPHOBIC POLYMER
PRE-POLYMERIZED POLYMERIZED IN PROCESS
Poly (e-caprolactone) (PECL)
Poly(isobutylcyanoacrylates)
(PICA)
Poly(lactic acid) (PLA) Poly(butylcyanoacrylates) (PBCA)
Poly(actide -co- glycolide (PLGA) Polyhexylcyanoacrylate (PHCA)
Polystyrene
Poly methyl
(methacrylate)(PMMA)

24. TECHNIQUES OF PREPARATION
IONIC
GELA
TION
POL
YMERIZA
TION
PREFOEMED
POLYMERS

25. METHODS OF PREPARATION OF NANOPARTICLES
BY DISPERSION OF PREFORMED POLYMER

26. METHOD FOR PREPARATION OF NANOPRATICLES
BY POLYMERIZATION OF MONOMERS
EMULSION
POLYMERIZA
TION
MINI- EMULSION
POLYMRIZA
TION
MICRO-EMULSION
POLYMRIZATION
INTERFACIACL
POLYMERIZA
TION
CONTROLLED/
LIVING
RADICAL
POLYMERIZATION

28. PREPARATION TECHNIQUES
Solvent Evaporation:-
• Solvent evaporation method first developed for preparation
of nanoparticles.
• In this method firstly nanoemulsion formulation prepared.
• Polymer dissolved in organic solvent (dichloromethane,
chloroform or ethyl acetate).
• Drug is dispersed in this solution.
• Then this mixuture emulsified in an aqueous phase
containing surfactant (polysorbates, poloxamers, polyvinyl
alcohol,).
• This make an oil in water emulsion by using mechanical
stirring, sonication, or micro fluidization (high-pressure
homogenization through narrow channels).

29. Representation of the solvent – evaporation technique.

30. Double Emulsification Method:-
•Emulsification and evaporation method have
limitation of poor entrapment OF hydrophilic
drugs, hence double emulsification technique is used.
•Firstly w/o emulsion prepared by addition of aqueous
drug solution to organic polymer solution with
continuous stirring.
•This prepared emulsion another aqueous phase with
vigorous stirring, resultant w/o/w emulsion prepared,
then organic solvent removed by high centrifugation.
PREPARATION TECHNIQUES

31. Emulsions - Diffusion Method:-
• This method patent by Leroux et al and it is modified form of
salting out method.
• Polymer dissolved in water-miscible solvent (propylene carbonate,
benzyl alcohol), this solution saturated with water.
• Polymer-water saturated solvent phase is emulsified in an aqueous
solution containing stabilizer. Then solvent removed by evaporation
or filtration.
PREPARATION TECHNIQUES

32. Nano precipitation method:-
• In this method precipitation of polymer and drug obtained from
organic solvent and the organic solvent diffused in to the
aqueous medium with or without presence of surfactant.
• Firstly drug was dissolved in water, and then cosolvent (acetone
used for make inner phase more homogeneous) was added into
this solution.
• Then another solution of polymer (ethyl cellulose, eudragit) and
propylene glycol with chloroform prepared, and this solution
was dispersed to the drug solution.
• This dispersion was slowly added to 10 ml of 70% aqueous
ethanol solution.
PREPARATION TECHNIQUES

33. • After 5 minutes of mixing, the organic solvents were
removed by evaporation at 35°under normal
pressure, nanoparticles were separated by using
cooling centrifuge (10000 rpm for 20 min),
supernatant were removed and nanoparticles washed
with water and dried at room temperature in a
desicator.
PREPARATION TECHNIQUES

34. Coacervation method:-
• Drug and protein solution (2% w/v) incubated for one hour at
room temperature and pH adjusted to 5.5 by using 1M HCl.
• In this solution ethanol was added in 2:1 ratio (v/v) in a controle
rate 1ml/min.
• Resultant coacervate hardened with 25% glutaraldehyde (1.56
μg/mg of protein) for 2 hours which allow cross-linking of
protein.
• Rotary Vacuum evaporation at reduced pressure
organic solvents were removed then nanoparticle were collected
and purified by centrifugation at four degree centigrade.
• Pellets of nanoparticles were then suspended in phosphate buffer
(pH 7.4; 0.1 M) and lyophilized with mannitol.
PREPARATION TECHNIQUES

35.  Salting Out Method:-
• Salting out method is very close to solvent
diffusion method.
• This technique is based on the separation of water-
miscible solvent from aqueous solution by salting
out effect.
• In this method toxic solvents are not used.
• Generally acetone is used because it is totally
miscible with water and easily removed.
PREPARATION TECHNIQUES

36. • Polymer and drug dissolved in a solvent which emulsified
into a aqueous solution containing salting out agent
(electrolytes, such as magnesium chloride and calcium
chloride, or nonelectrolytes such as sucrose).
PREPARATION TECHNIQUES

37. DIALYSIS:-
Dialysis is an effective method for
preparation of nanoparticles.
In this method firstly polymer (such
as Poly (benzyl-glutamate)-b-
poly(ethylene oxide), Poly(lactide)
and drug dissolved in a organic
solvent.
This solution added to a dialysis
tube and dialysis performed.
PREPARATION TECHNIQUES

38. EVALUATION PARAMETER OF NANOPARTICLES
1) YIELD OF NANOPARTICLES:-
PrecentageYield = Amount of particle (100)
Amount of drug+ polymer
2) DRUG CONTENT/SURFACE
ENTRAPMENT/ DRUG ENTRAPMENT:-
Precentage drug entrapment = W-w (100)
W
3) PARTICLE SIZE:- Particle size and its distribution is important
characteristics in nanoparticles as they plays major role in distribution,
pharmacological activity, toxicity and targeting to specific sites.
Advanced methods to determine the particle size of nanoparticles is by
photon-correlation spectroscopy or dynamic light scattering, scanning
electron microscopy

39. 4) PARTICLE SHAPE:- Particle shape of the nano suspensions is
determined by scanning electron microscopy (SEM). In order to form the
solid particles these nano suspensions were subjected to lyophilisation.
5) ZETA POTENTIAL:- Zeta potential is the potential difference
existing between the surface of a solid particle immersed in a conducting
liquid and the bulk of the liquid. The surface charge of the nanoparticles is
usually measured by zeta potential.
4) DIFFERENTIAL SCANNING CALORIMERTY (DSC):-
It is used to determine the nature of crystallinity within nanoparticles
through the measurement of glass and melting point tempertures and their
associated enthalpies.
5) ATOMIC FORCE MICROSCOPY (AFM):- It offers a ultra-
high resolution in particle size measurement and is based on a physical
scanning of sample at sub- micron level using a probe tip of atomic scale.
AFM provides the most accurate description of size and size distribution
and requires nom mathemical treatment.

40. DRUG LOADING
INCORPORATION METHOD
INCUBATION METHOD
INCORPORATION METHOD- Incorporating at the time of nanoparticle
production
INCUBATION METHOD- Adsorbing the drug after the formation of
nanoparticles by incubating the carrier with the concentrated drug
solution.
Both methods result in:
 Asolid solution of the drug in the polymers
 Solid dispersion of the dug in the polymer.
 Surface adsorption of the drug.
 Chemical bonding of the drug in the polymer.

41. DRUG RELEASE AND RELEASE KINETIC
The release of drug from
the particulate system
depends upon three
different mechanism:
 Release from the
surface of particles.
 Diffusion through
the swollen rubbery
matrix.
 Release due to erosion.

42. EVALUATION FOR RELEASE OF DRUG
Various methods which can be used to study the in vitro
release of the drug from nanoparticles are:
1. Side-by- side diffusion cells with artifical or biological
membranes
2. Dialysis bag diffusion technique
3. Reverse dialysis bag technique
4. Agitation followed by ultracentrifugation/ centrifugation
5. Ultra- filtration or centrifugal ultra- filtration techniques

43. IN VITRO DRUG RELEASE STUDIES
USPType 2
RPM 50
Immersed in 900
ml of phosphate
buffer solution
Temperature 37+
0.02 degree
Celsius
Withdrawn 5ml
solution from the
medium
Specific time
periods
• DISSOLUTION:-
Same vol. of
dissolution
medium replaced
in the flask
Maintain the
constant volume
Withdrawn
samples analyzed
using UV
Spectrophotomete
rer

44. • STABILITY OF NANOPARTICLES:-
• Nanoparticles
detemination
• Storing
optimized
formulation
4 degree Celsius + 1
degree Celsius & 30
dergree celsius + 2
dergree celsius
0,1,2 & 3 month
time period
• Sample
analyzed
• Stability
chamber for 90
days
• Any changes in
physical
appearance
Their drug
content, drug
release rate

45. APPLICATIONS
USED IN TARGETED DRUG DELIVERYTO BRAIN THERAPY
USED IN TARGETING OF NANOPRATICLES
TO EPITHELIAL CELLS IN THE GI TRACT
USING LIGANDS
USED IN BIO
DECTECTION OF
PATHOGENS
STEM CELL
THERAPY
NANOPARTICLES
FOR GENE
DELIVERY
CANCER THERAPY

46. TYPES OF NANOPARTICLES
Nanoparticles can be classified into different types according to
the size, morphology, physical and chemical properties. Some of
them are;
1.Carbon-based nanoparticles
2.Ceramic nanoparticles
3. Metal nanoparticles
4. Semiconductor nanoparticles
5. Polymeric nanoparticles
6. Lipid-based nanoparticles

47. 1. Carbon-based nanoparticles: It includes two main materials:
a. Carbon nanotubes (CNTs).
b. Fullerenes.
CNTs are nothing but graphene sheets rolled into a tube. These materials are mainly used for
the structural reinforcement as they are 100 times.
Where as; Fullerenes are the allotropes of carbon having a structure of hollow cage of sixty or
more carbon atoms. The structure of C-60 is also called Buckminsterfullerene.
2. Ceramic Nanoparticles
• Ceramic nanoparticles are inorganic solids made up of oxides, carbides, carbonates and
phosphates.
• These nanoparticles have high heat resistance and chemical inertness.
• They have applications in photocatalysis, photodegradation of dyes, drug delivery, and
imaging.
3. Metal Nanoparticles
• Metal nanoparticles are prepared from metal precursors.
• These nanoparticles can be synthesized by chemical, electrochemical, or photochemical
methods.
• These nanoparticles have applications in detection and imaging of biomolecules and in
environmental and bioanalytical applications.
TYPES OF NANOPARTICLES

48. TYPES OF NANOPARTICLES
4. Semiconductor Nanoparticles
• Semiconductor nanoparticles have properties like those of metals and non-metals.
• These particles have wide bandgaps, which on tuning shows different properties.
• They are used in photocatalysis, electronics devices, photo-optics and water splitting
applications.
• Some examples are Gan,Gap,Inp etc.from group III.
5. Polymeric Nanoparticles
• Polymeric nanoparticles are organic based nanoparticles.
• Depending upon the method of preparation, these have structures shaped like
nanocapsular or nanospheres. A nanosphere particle has a matrix-like structure whereas the
nanocapsular particle has core-shell morphology.
6. Lipid-Based Nanoparticles
• Lipid nanoparticles are generally spherical in shape with a diameter ranging from 10 to
100nm.
• It consists of a solid core made of lipid and a matrix containing soluble lipophilic
molecules.
• The external core of these nanoparticles is stabilized by surfactants and emulsifiers.

49. Liposomes

50. Liposomes are concentric bilayered vesicles in
which an aqueous core is entirely enclosed by
a membranous lipid bilayer mainly composed
of natural or synthetic phospholipids.
LIPOSOMES

51. •Liposomes are extensively used as carriers for
numerous molecules in cosmetic and pharmaceutical
industries. Additionally, food and farming industries
have extensively studied the use of liposome
encapsulation to grow delivery systems that can entrap
unstable compounds (for example, antimicrobials,
antioxidants, flavors and bioactive elements) and shield
their functionality.
•The size of a liposome ranges from some 20 nm up to
several micrometers.
LIPOSOMES

52. Basic structure of liposome
•A Lamella is a flat plate
like structure that
appears during the
formation of liposomes.
•The phospholipids
bilayer first exists as a
lamella before getting
converted into spheres.
•Several lamella of
phospholipids bilayers
are stacked one on top
of the other during
formation of liposomes
to form a multilamellar
structure.

53. •Provides selective passive targeting to tumor
tissues.
•Increased efficacy and therapeutic index.
•Increased stability of encapsulated drug.
•Reduction in toxicity of the encapsulated agent.
•Improved pharmacokinetic effects.
•Site avoidance effect (avoids non-target tissues).
Liposomes are non-toxic, flexible, biocompatible,
completely biodegradable, and nonimmunogenic
for systemic and non-systemic administrations.
ADVANTAGES OF LIPOSOMES

54. •Physical/ chemical stability.
•Very high production cost.
•Drug leakage/ entrapment/ drug fusion.
•Sterilization.
•Short biological activity / t ½.
•Oxidation of bilayer phospholipids.
•Overcoming resistance.
•Repeated iv administration problems.
DISADVANTAGES

55. PREPARATION OF LIPOSOMES
General methods of preparation
All the methods of preparing the liposomes involve four
basic stages:
1. Drying down lipids from organic solvent.
2. Dispersing the lipid in aqueous media.
3. Purifying the resultant liposome.
4. Analyzing the final product.
Method of liposome preparation and drug loading
The following methods are used for the preparation of
liposome:
1. Passive loading techniques
2. Active loading technique.

56. PREPARATION OF LIPOSOMES
Passive loading techniques include three different methods:
1. Mechanical dispersion method.
2. Solvent dispersion method.
3. Detergent removal method (removal of nonencapsulated material)
1. Mechanical dispersion method
The following are types of mechanical dispersion methods:
1.1. Sonication.
1.2. French pressure cell: extrusion.
1.3. Freeze-thawed liposomes.
1.4. Lipid film hydration by hand shaking, non-hand. shaking or freeze drying.
1.5. Micro-emulsification.
1.6. Membrane extrusion.
1.7. Dried reconstituted vesicle.

57. PREPARATION OF LIPOSOMES
2. Solvent dispersion method:-
This methods includes:
2.1Ethanol injection.
2.2Ether injection.
2.3Double emulsion vesicles.
2.4Stable plurilamellar.
2.5Vesicles.
2.6Reverse phase evaporation vesicles.
3. Detergent removal method (removal of nonencapsulated material):-
This methods includes detergent(Cholate,Alkylglycoside,Triton X-100) removal
from mixed micelles by:
3.1Dialysis.
3.2Column chromatography.
3.3Dilution.
3.4Reconstituted sendai virus enveloped vesicles.

58. Evaluation of liposomes
Physical properties
1. Particle size: Both particle size and particle size distribution of
liposomes influence their physical stability. These can be determined
by the following method.
A. Laser light scattering.
B. Transmission electron microscopy.
2. Surface charge: This technique can be used for determining the
heterogeneity of charges in the liposome suspension as well as to
detect any impurities such as fatty acids.
1. The positive, negative or neutral charge on the surface of the
liposomes is due to the composition of the head groups.
2. The surface charge of liposomes governs the kinetic and extent
of distribution in vivo, as well as interaction with the target cells.
3. The method involved in the measurement of surface charge is
based on free-flow electrophoresis of MLVs.

59. 3. Percent drug encapsulated
• Quantity of drug entrapped in the liposomes helps to estimate the behavior of the
drug in biological system.
• Liposomes are mixture of encapsulated and unencapsulated drug fractions.
• The % of drug encapsulation is done by first separating the free drug fraction
from encapsulated drug fraction.
4. Phase behavior
• At transition temperature liposomes undergo reversible phase transition.
• The transition temperature is the indication of stability permeability and also
indicates the region of drug entrapment.
• Done by DSC.
5. Drug Release Rate
• The rate of drug release from the liposomes can be determined by in vivo
assays which helps to predict the pharmacokinetics and bioavailability of the
drug.
• However in vivo studies are found to be more complete.
Evaluation of liposomes

60. Benefits of drug load in liposomes
Sr.No. Benefits of drug load in liposome Examples
1. Improved solubility of lipophilic and
amphiphilic drugs
Amphotericin B, porphyrins, minoxidil, some
peptides, and anthracyclines,
respectively; hydrophilic drugs, such as
anticancer agent doxorubicin or acyclovir
2. Passive targeting to the cells of the
immune system, especially cells of the
mononuclear phagocytic system
Antimonials, amphotericin B, porphyrins,
vaccines, immunomodulators
3. Sustained release system of systemically
or locally administered liposomes
Doxorubicin, cytosine arabinoside, cortisones,
biological proteins or peptides such as
vasopressin
4. Site-avoidance mechanism Doxorubicin andamphotericin B
5. Site-specific targeting Anti-inflammatory drugs, anti-cancer, anti-
infection
6. Improved transfer of hydrophilic,
charged molecules
Antibiotics, chelators, plasmids, and genes
7. Improved penetration into tissues Corticosteroids, anesthetics, and insulin

61. • Liposomes as drug or protein delivery vehicles.
• Liposome in antimicrobial, antifungal (lung
therapeutics) and antiviral (anti HIV) therapy.
• In tumor therapy.
• In gene therapy.
• In immunology.
• Liposomes as artificial blood surrogates.
APPLICATIONS