The presentation will give a complete information about Ophthalmic inserts, its classification, and evaluation parameters.

2. Introduction
Traditional topical ophthalmic formulations have
poor bioavailability because of rapid precorneal
elimination, conjunctival absorption, solution
drainage by gravity. This leads to frequent
administration of doses to achieve the
therapeutic effect.
Ophthalmic dosage forms such as ointments,
gels, solutions have many disadvantages(vision
blurring, frequent administration due to
drainage, irritations, etc) therefore there was
need to formulate such a delivery system that
was more advantageous than conventional
ophthalmic dosage form.

3. Ophthalmic Inserts (Ocular Inserts):
Ophthalmic inserts are defined as sterile
preparations, with a solid or semisolid
consistency, and whose size and shape are
especially designed for ophthalmic application.
They are composed of a polymeric support.
The main objective of the ophthalmic inserts is to
increase the contact time between the
preparation and the conjunctival tissue to ensure
a sustained release suited to topical or systemic
treatment.
Advantages : Increasing contact time, possibility
of providing a prolonged drug release, reduction
of the number of administrations, administration
of an accurate dose in the eye.

4. Classification of Ocular Inserts

5. 1. Insoluble Ophthalmic Inserts
The insoluble inserts have been classified in
three groups: the diffusional systems, the
osmotic systems and the hydrophilic contact
lenses.
a. Diffusional Inserts : The diffusional
systems are composed of a central reservoir
of drug enclosed in specially designed
semipermeable or microporous membranes
which allow the drug to diffuse from the
reservoir at a precisely determined rate. The
drug release from such a system is controled
by the lacrimal fluid permeating through the
membrane until a sufficient internal pressure
is reached to drive the drug out of the
reservoir.

6. b. Osmotic Inserts:
The osmotic inserts are generally
composed of a central part surrounded by
a peripheral part. The first central part
can be composed of a single reservoir or
of two distinct compartments. The second
peripheral part of these osmotic inserts
comprises in all cases a covering film
made of an insoluble semipermeable
polymer.

7. c. Contact Lens: These structure are
made up of a covalently cross-linked
hydrophilic or hydrophobic polymer that
forms a three dimensional matrix capable
of retaining water, aqueous solution or
solid components.
When a hydrophilic contact lens is soaked
in a drug solution, it absorbs the drug.
Contact lenses have good prospects as
ocular drug delivery systems.

8. 2. Soluble Ophthalmic Inserts
They offer the great advantage of being
entirely soluble so that they do not need
to be removed from their site of
application, thus limiting the interventions
to insertion only.
Soluble natural
polymers
Collagen derivatives:
collagen type I, 11, 111 and IV, cross
linked collagens
Chitosan derivatives: chitosan base,
acetylated chitosan
Additives Binding agents:
anionic: carboxylated collagens,
carboxylated celluloses, polyacrylic acid,
chitin, chitosan
Plasticizers:
water, polyethylene glycol, glycol

9. 3. Bioerodible Ophthalmic Inserts:
The bioerodible inserts are composed of
matricial homogeneous dispersion of a
drug included or not into a hydrophobic
coating which is substantially
impermeable to the drug.
The main components used for the
production of this type of inserts are the
bioerodible polymers, i.e. materials that
undergo hydrolysis of chemical bonds and
hence dissolution.

10. Evaluation of Ocular Polymeric Films
1. Thickness of film
2. Drug content uniformity
3. Uniformity of weight
4. Percentage moisture absorption
5. Percentage moisture loss
6. In-vitro drug release
7. In-vivo drug release rate study
8. Accelerated stability studies
9. Test for sterility
10. Growth promotion test

11. References
Anita Kumari, Pramod K. Sharma,Vipin K.
Garg, Garima Garg, Ocular inserts
Advancement in therapy of eye diseases,
Journal of Advanced Pharmaceutical
Technology & Research · July 2010
F. GURTLEARN D R. GURNY, PATENT
LITERATURE REVIEW OF OPHTHALMIC
INSERTS, SCHOOL OF PHARMACY
UNIVERSITY OF GENEVA , CH-1211
GENEVA,SWITZERLAND