MAGNETICALLY MODULATED DRUG DELIVERY SYSTEMS

1. Presented by
SARANG VILAS DALVI
GOVERNMENT COLLEGE OF PHARMACY
Amravati 444 604, MS, India

2.  INTRODUCTION
 Drug targeting : Delivery of drugs to receptors or organ or any other
specific part of the body exclusively.
 Magnetic Drug Targeting means the specific delivery of therapeutic
agents to their desired target area using magnetic feild .
 Magnetic fields are believed to be harmless to biological systems and
adaptable to any part of the body.
 Magnetic particles composed of magnetite are well tolerated by body.

3.  PRINCIPLE
 In the process the drug is bound to the magnetic compound, injected in
blood stream and stoped with magnetic field in target area.
 Magnetic compounds used to bind to drug are such as magnetite, iron,
nickel, cobalt, neodymium, iron–boron.
 Magnetic drug delivery by particulate carriers is a very efficient method
of delivering drug to a localized disease site.
 Very high concentrations of chemotherapeutic or radiological agents can
be achieved near the target site, such as a tumour.

4.  Up to 60 % of an injected dose can deposited and released in controlled
manner in selected organs.
Little access
Little access
Major pathway
Major pathway
RES organ
(liver/spleen/bone marrow)
Drug/Carrier Circulation
RES organ
(liver/spleen/bone marrow)
Magnetic
Drug/Carrier Circulation
Target tissue
Target tissue
N
S
Fig 1: Principle of Magnetic Drug Targeting.

5.  MECHANISM
 Magnetic drug transport technique is based on the fact that the drug can
be either encapsulated into a magnetic microsphere (or nanosphere) or
conjugated on the surface of the micro/nanosphere.
 When the magnetic carrier is intravenously administered, the
accumulation take place within area to which the magnetic field is
applied.
 An external permanent magnetic field is applied on desired area to guide
and concentrate the drugs.

7.  Efficiency of accumulation of magnetic carrier depends on physiological
parameters eg. Particle size, surface characteristic, field strength, and
blood flow rate etc.
 This technique give us a major advantage that target the specific area and
reduce the systemic distribution of drugs and result in effective treatment
at lower doses.

8.  systemic drug deivery vs Magnetic drug delivery

9.  ADVANTAGS
 Harmless to biological systems and adaptable to any part of the
body.
 Therapeutic responses in the target organs at only one tenth of
the free drug dose.
 Controlled drug release within target issues for intervals of 30
min to 30 hrs.
 Decline in normal cell tissue damage rate.
 Minimizes side effects risk.
 This drug delivery system reduces circulating concentration of
free drug by a factor of 100 or more.

10. DISADVANTAGES
 Magnetic targeting is an expensive, technical approach and
acquires specialized manufacture and quality control system.
 It needs specialized magnet for targeting, advanced techniques
for monitoring, and trained personnel to perform procedures.
 Magnet must have relatively constant gradients, in order to avoid
focal over dosing with toxic drugs.
 Drug cannot be targeted to deep seated organs in the body.
 Drug targeting can be done in superficial tissue only like skin,
superficial tumour or to joints only.

11.  MAGETICALLY MODULATED CARRIERS
 Following are the various magnetic carriers :
A. Magnetic microsphere.
B. Magnetic liposomes.
C. Magnetic nanoparticles.
D. Magnetic Resealed Erythrocytes.
E. Magnetic Emulsion.
F. Magnetic neutrophils.

12. A. Magnetic microsphere.
 Magnetic microspheres are supramolecular particles that are small
enough to circulate through capillaries without producing embolic
occlusion.
 They are having a particle size ranging from 1-1000μm.
 The loaded microspheres are introduced into a
blood vessel, and in as little as half an hour, they
gather at the target site

13. Evaluation Parameters:
1.Particle size analysis.
2.Micrometric properties.
3. Bulk Density.
4.Tapped Density.
5.Carr’s Index.
6.Hausner’s Ratio.
7.Angle of Repose.
8.Stability studies.

14. B. Magnetic liposomes.
 Liposomes are simple microscopic vesicles in which lipid bilayer
structures are present with an aqueous volume entirely enclosed by a
membrane, composed of lipid molecule.
 There are a number of components present in liposomes with
phospholipids and cholesterol being the main ingredients but in case of
magneto liposomes magnetite is one of the components of the liposomes.
Fig : Structure of magnetic liposomes.

15. C. Magnetic nanoparticles.
 Magnetic nanoparticles (MNPs) possess unique magnetic properties and
the ability to function at the cellular and molecular level of biological
interactions making them an attractive platform.
 MNPs are now being developed for applications in the detection,
diagnosis, and treatment of malignant tumors, cardiovascular disease,
and neurological disease.
 They can be synthesized using different methods like co-precipitation,
thermal decomposition and micro emulsion method.

16. D. Magnetic Resealed Erythrocytes.
 Resealed erythrocytes have various advantages as drug carriers such as it
is-
• biodegradable.
• biocompatible.
• large quantity of variety of material can be encapsulated within
small volume of cell.
• and can be utilized for organ targeting.
 Magnetic resealed erythrocytes contains ferrofluides (magnetite) along
with loaded drugs within the cell.

17.  APPLICATIONS
 Some of the application of magnetically modulated drug targeting
especially tumor targeting along with some other application are -
1.Magnetic systems for the therapy of diseases.
• Magnetic delivery of chemotherapeutic drugs to liver tumors.
• Magnetic targeting of radioactivity.
• Treatment of tumors with magnetically induced hyperthermia.
• Other magnetic targeting applications.
• Magnetic control of pharmacokinetic parameters and drug release.
2.Magnetic systems for the diagnosis of diseases.
3.Magnetic systems for magnetic cell separation.

18. FUTURE PRESSPECTIVE
 Conceptually, magnetic targeting is a very promising approach.
However, there are a number of physical, magnetism-related properties
which require careful attention.
 First, the magnetic force, which is defined by its field and field gradient,
needs to be large and carefully shaped to fit the target area.
 Beside the magnetic properties, the fate of the particles in the body is an
important consideration both for local and systemic short- and long-term
toxicity.

19.  CONCLUSION
 Magnetic Drug targeting is efficient & novel approach of drug targeting .
 Larger amount of freely circulating drug can be replaced by smaller
amount of magnetically targeted drug.
 It is a challenging area for future research in the drug targeting.
 More researches, long term toxicity study, and characterization will
ensure the improvement of magnetic drug delivery system.