1. By
shiva
B.pharmacy

2.  Definition: They are specialized dosage forms designed to
be instilled onto the external surface of the eye (topical),
administered inside (intraocular) or adjacent (periocular)
to the eye or used in conjunction with an ophthalmic
device.
 Conventional ophthalmic dosage forms (solutions,
suspensions, ointments, etc) after instillation into the eye,
are rapidly drained away from the ocular cavity due to
tear flow and lacrimal nasal drainage.
 The newest dosage forms for ophthalmic drug delivery are:
liposomes, nanoparticles ,mucoadhesives,ocular inserts.

3. LIMITATIONS OF CONVENTIONAL DRUG
DELIVERY
 Solution drainage by gravity
 Frequent instillation is necessary
 Conjuctival absorption
ADVANTAGES OF AVANCED DUG DELIVERY
 Sustained and/or controlled drug release
 Site-specific targeting
 Protect the drug from chemical or enzymatic
hydrolysis
 Increasing contact time and thus improving
bioavailability
 Better patient compliance.

4. 1. Sclera,
2. Choroids,
3. Cornea,
4. Cilliary
Body- Secretion
of aq. humor,
5. Lens,
6. Retina,
7. Conjuctiva,
8. Vitreous
Compartment,
9. Lacrimal
gland.

5. • Penetration across Sclera & Conjuctiva into Intra
Ocular tissues
• Non-Productive: because penetrated drug is
Non-Corneal absorbed by general circulation
Absorption
• Outer Epithelium: rate limiting barrier, with
pore size 60å,Only access to small ionic &
lipophillic molecules
Corneal • Trans cellular transport: transport between
corneal epithelium & stroma.
Absorption

6.  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,
carboxymethylcellulose,cross-linked
polyacrylic acid
Drugs incorporated in to this are pilocarpine,
lidocaine, benzocaine and prednisolone acetate.

7. • 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

8.  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.

9. * 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

11. 1. Ocusert: is a multilayered structure consisting of a
drug containing core surrounded on each side by a
layer of copolymer membranes through which the
drug diffuses at a constant rate.
 The rate of drug diffusion is controlled by:
- The polymer composition
- The membrane thickness
- The solubility of the drug
e.g. The Ocusert® Pilo-20 and Pilo-40 Ocular system
- Designed to be placed in the inferior cul-de-sac
between the sclera and the eyelid and to release
pilocarpine continuously at a steady rate for 7days.
- consists of (a) a drug reservoir, pilocarpine (free base),
and a carrier material, alginic acid: (b) a rate controller
ethylene vinyl acetate (EVA) copolymer membrane.

12. 2. 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.

13. 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:
•Single SODI application : replaces 4-12 eye drops Instillation, or
3-6 application of Ointments.
•Once a day treatment of Glaucoma.

14. 2.Lacrisert:
• Sterile, Rod Shaped device.
• Composition: HPC.
• Weight:5mg,
• Dimension:Diameter:12.5mm, Length:3.5mm
• Use:-Dry eye treatment.
3.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.

15.  Vesicle composed of phospholipid bilayer enclosing
aqueous compartment in alternate fashion.
 Biodegradable, Non-toxic in nature.
 Types :1.MLV
2.ULV-SUV( upto 100 nm)
3. LUV(more than 100 nm)
 Polar drugs are incorporated in aqueous compartment while
lipophilic drug are intercalated into the liposome membrane.
 Phospholipids used- Phophotidylcholine, Phosphotidic
acid, Phosphotidyleserine,Cardiolipine

16. ADVANTAGES
 Drugs delivered intact to various body tissues.
 Liposomes can be used for both hydrophilic
and hydrophobic drug.
 Possibility of targeting and decrease drug
toxicity.
 The size, charge and other characteristics can
be altered according to drug and desired tissue.
 DISADVANTAGES OF LIPOSOMES
 They need many modification for drug delivery to special
organs.
 Cost .

17.  For water soluble drugs
 Size is about 10-1000 nm
 Drug is dispersed, encapsulated or absorbed
 Produced by emulsion polymerization
 Polymerization is carried out by chemical
initiation, or by irradiation with gamma rays, uv or
visible light.
 Polymer used are biodegradable.
 E.g: Nanoparticles of pilocarpine have shown an
enhanced miotic response by about 22-23%.

18. 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.