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1. 1
ADVANCES IN OCULAR
DRUG DELIVERY SYSTEM

2. 2
CONTENTS
Objectives
Introduction
Anatomy Of Eye
Barriers In Ocular Absorption
Ocular Absorption
Use of Mucoadhesives in Ocular Drug Delivery
Nanoparticulate Dug Delivery
Ocular Inserts
Liposomes In Ocular Drug Delivery
Future trends
Conclusion
References

3. 3
OBJECTIVES
To study the ocular drug delivery system
in detail.
To explore the success, limitations and
future trends of ocular drug delivery
system.

4. 4
INTRODUCTION
• A drug delivery to circumvent ailments of
eye.
• A challenge to formulator is to avoid
protective barrier of eye
• Importance of cornea.
• Conventional ocular drug delivery system
• Need of a successful design

5. 5

6. 6
OCULAR
ANATOMY
AND
PHYSIOLOGY

7. ANATOMY OF 7
EYE

8. 8
BARRIERS IN OCULAR
ABSORPTION
Precorneal Constraints Corneal constraints
It include –
• Solution drainage • Cornea as rate limiting barrier
• Lacrimation • Anatomy of cornea
• Tear dilution 1.Outer-Epithelium(lipophilic),
• Tear turnover 2.Middle-Stroma(hydrophilic),
• Conjunctival absorption 3.Inner-Endothelium(lipophilic

9. 9
OCULAR ABSORPTION

10. 10
GENERAL PATHWAY
FOR OCULAR
ABSORPTION

11. 11
ADVANCED OCULAR
DRUG DELIVERY
SYSTEMS

12. 12
USE OF MUCOADHESIVES
IN OCULAR DRUG
DELIVERY
• Mucoadhesives contain the dosage form which
remains adhered to cornea until the polymer is
degraded or mucus replaces itself.
• Types-
1. Naturally Occurring Mucoadhesives- Lectins,
Fibronectins
2. Synthetic Mucoadhesives-PVA,Carbopol, carboxy
methyl cellulose, cross-linked polyacrylic acid
• Drugs incarporated in to this are pilocarpine,
lidocaine, benzocaine and prednisolone acetate.

13. 13
Mechanism of mucoadhesion
• The polymer undergoes
swelling in water,
• Entanglement of the polymer
chains with mucin on the
epithelial surface.
• The un-ionized carboxylic acid
residues on the polymer form
hydrogen bonds with the
mucin.
• The water-swellable yet water-
insoluble systems are preferred

14. 14
NANOPARTICULATE
DRUG DELIVERY

15. 15
Advantages of nanoparticles
• Sustained drug release and prolonged therapeutic
activity
• Site-specific targeting
• Higher cellular permeability
• Protect the drug from chemical or enzymatic
hydrolysis
• Efficient in crossing membrane barriers -blood retinal
barrier
• Act as an inert carrier for ophthalmic drugs

16. 16
Preparation of Nanoparticles
Solvent evaporation method

17. 17

18. 18
OCULAR INSERTS
• Sterile preparations, with a thin, multilayered, drug-
impregnated, solid or semisolid consistency devices
placed into cul-de-sac or conjunctival sac.
Advantages
• Increasing contact time and thus improving
bioavailability.
• Providing a prolong drug release and thus a better
efficacy.
• Reduction of systemic side effects and thus reduced
adverse effects.
• Reduction of the number of administrations and thus
better patient compliance.

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Desired criteria for ocular inserts
* Ease of handling and insertion
* Lack of expulsion during wear
* Reproducibility of release kinetics (Zero-order
drug delivery)
* Applicability to variety of drugs
* Non-interference with vision and oxygen
permeability.
* Sterility.
* Ease of manufacture

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21. 21
A) Insoluble inserts-
1. Diffusional Inserts :
•Central reservoir of drug
enclosed in Semi permeable or
microporous membrane for
diffusion of drug.
•Diffusion is controlled by
Lacrimal Fluid penetrating
through it.
•Release follows : Zero Order
Kinetics.
e.g. Ocusert®:
 20-40µg/hr for 7day
 Annular ring : Impregnated with Ti02 : For Visibility

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2) Osmotic inserts
• A central part surrounded by a peripheral part
• Central part-single reservoir or two distinct compartments.
• Peripheral part- an insoluble semi permeable polymer.
•The tear fluid diffuse and induces dissolution.
•Solubilized deposits generate a hydrostatic pressure.
•Drug is then released through these apertures
3) Contact Lens :
• Presoaked Hydrophilic lens.
• Drug Release : within 1st 30 Min.
• Alternate approach : incorporate drug either as soln or
suspension .e.g. Pilocarpine.
• Release rate is up to : 180 hr.

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B) Soluble Inserts
1.SODI: Soluble Ocular Drug Insert.
• Small water soluble made of soluble synthetic polymers.
• Composition : Acryl amide, Vinyl Pyrolidone, Ethylacrylate.
• Weight 15-16 mg.
In 10-15 sec Softens;
In 10-15 min. turns in Viscous Liquids;
After 30-60min. Becomes Polymeric Solution.
Advantages of SODI :
•Single SODI application : replaces 4-12 eye drops Instillation, or
3-6 application of Ointments.
•Once a day treatment of Glaucoma.

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2.The corneal collagen shield
• A disposable, short-term therapeutic bandage lens for the
cornea.
• It conforms to the shape of the eye, protects the corneal
surface, and provides lubrication as it dissolves.
• The shields are derived from bovine collagen and are 14.5 mm
in diameter.
• Sterilized by gamma irradiation.
Disadvantages
1.It is not optically clear.
2.The collagen shield causes some discomfort.
Clinical uses
1.Wound healing.
2.Treatment of dry eye.

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C) Biodegradable inserts
1.Lacrisert:
• Sterile, Rod Shaped device.
• Composition: HPC.
• Weight:5mg,
• Dimension:Diameter:12.5mm, Length:3.5mm
• Use:-Dry eye treatment.
2.Minidisc:
• It is made up of counter disc with Convex front & Concave back
surface in contact with eye ball.
• 4-5mm in diameter.
• Composition : Silicon based polymer.
• Drug release upto170 hr.

26. 26
LIPOSOMES

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28. 28
Preparation Of Liposomes
Reverse phase evaporation method

29. 29
Degradation and Drug Release Of
Liposomes
1. Endocytosis
2. Fusion

30. 30
FUTURE TRENDS
The sustained and controlled release technologies are
being proposed and the possible benefits of using
liposomes, nanoparticles and inserts will be at store
in future.
Targeted drug delivery with modifications of
conventional, advanced and novel ocular drug
deliveries has potential as future drug delivery for
eye.
It is possible to the give effective ocular drug delivery
to any part of the eye.

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CONCLUSION
• Very few advanced ocular drug delivery systems
have been commercialized.
• The performance of these new products, however,
is still far from being perfect.
• Major improvements are required in each of the
technologies discussed in this study.
• More clinical studies are necessary to provide
further information and insights into these
advanced ocular drug delivery systems.

32. 32
REFERENCES
• Mitra Ashim k., Opthalmic Drug Delivery System, Marcel
Dekker Inc., 1993,1-59,83-111,199-289.
• Jain N.K., Controlled and Novel Drug Delivery, CBS
Publisher, 2004, 82-100.
• Das Swarnali, K. Preeti, Drug delivery to eye: Special
reference to nanoparticles, International Journal of Drug
Delivery 2, 2010, 12-21.
• Rathore K. S., R. Nema, Review on Ocular Inserts Int.J.
PharmTech Res.2009, 1(2),164-169.
Web Searched:
• http://www.google/images/eye/anatomy& physiology

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The eyes are the mirror of the soul…
Take care of your eyes with gentleness.