3. What is eye drop ?
Eye Drops are liquid drops applied directly to the surface of the eye usually in
small amounts such as a single drop or a few drop.
Eye drops have less of a risk of side effects.
Eyes drops usually contain saline to match the salinity of eye.
These are the formulation which are sterile in nature.
They use for instillation into the eye b/w the eyelid and eye ball.
Eye drops may also contain one or more medications to treat a wide variety of
eye diseases.
4. Ideal characteristics of eye drops :-
It should be sterile.
Their should be no leakage in the container containing eye drop solution.
It must be easy to install by the patient.
Particle Limitation
pH , Stability and Eye comfort
These eye drops are packed for single use , without preservatives
5. Classification of ODDS(ocular drug delivery system)
Liquids Semisolids Solid Intraocular
Dosage Form
Solutions Ointments Ocular inserts Injection
Suspension Gels Contact lenses Irrigating Solution
Powders for
reconstitution
Implants
Sol to Gel system
6. Requirements for ophthalmic preparation:-
Ophthalmic preparation should possess the following properties-
Foreign Particles
Tonicity
pH of preparations
Sterility
Surface activity
7. Foreign Particles:-
All the ophthalmic preparation should be clear and free from foreign particles , fibres and
filaments.
Ophthalmic solution should be clarifies very carefully by passing through membrane filter
and sintered glass filter.
The particle size of the eye suspension should be in an ultrafine state to minimize
irritation.
A separate filter should be used for different ophthalmic products in order to avoid the
contamination.
8. Viscosity :-
TO provide prolong action.
Increase the contact time of the drug in the eye.
Eg- Polyvinyl alcohol , Polyethylene glycol , methyl cellulose , carboxy methyl cellulose
are some thickening agents use
Thickening have some properties:-
Easy to filter
Easy to sterilize
Compatible with other ingredients
9. Tonicity:-
Ophthalmic product should be isotonic with lacrimal secretion to avoid discomfort and
irritation in eyes.
Range of tonicity that eye tolerate is from 0.5-2% Nacl.
Isotonic vehicle- 1.9% boric acid , sodium acid phosphate buffer.
10. pH of the preparation:-
pH plays an important role in therapeutic activity , solubility , stability and comfort to the
patient.
TEAR have a pH of about 7.4
Eye can tolerate solution which have pH as pH of eye.
Alkaloid salt solution are stable at pH 2-3 but this pH cause irritation in eye.
Alkaloids get ppt. at pH 7 or above and cause a number of formulation problems.
12. Drug
These contains drug of various categories including antiseptic , antiinflamatory agent etc.
Preservative
Eye drops should be sterile and should contain preservatives to avoid microbial
contamination when the container is open.
Eg- Benzalkonium chloride , Phenylmercuric nitrate ,Phenylmercuric acetate.
Sterilization
Eye drops are sterilized by autoclaving at 121^c for 15 minute
By bacteria filter to avoid thermal degradation like- preservative chlorobutanol hydrochloride
at high temperature.
13. Isotonicity
All the solutes including Drug should maintain the osmatic pressure of the Eye drops ,
therefore the isotonicity of the formulation is calculated.
NaCl 0.9% and boric acid 1.9% are iso-osmotic.
Buffer
To maintain the pH of the formulation , solubility , stability and eye comfort.
Alkaloids show ppt. at pH 7 so the most common buffer for eye comfort is sodium phosphate.
Viscosity
The size of Drop and its residences in eye depends on the viscosity of eye drop.
Eg- Methylcellulose , hydroxypropyl methylcellulose and polyvinyl alcohol are common
viscosity enhances.
14. Labeling
Name and concentration of drug
Direction of use
Company name
Date after note to use
For external use only
15. Container
The commonly used container for ophthalmic solution or suspension is multiple dose
container (5 ml, 10 ml)
Glass container is supplied with sterile plastic dropper, plastic bottles are with built with
nozzle.