Eye, ear and nasal drops are sterile aqueous or oily solutions meant for instillation into respective areas. Eye drops contain drugs that are antiseptic, anesthetic, anti-inflammatory or cause pupil dilation/constriction. Ear drops and nasal drops contain medications to relieve conditions like congestion. All three include active ingredients, vehicles, preservatives and adjuvants in suitable containers. They must be free of particles, sterile, have proper pH, tonicity, viscosity, surface activity and not cause irritation. Thickening agents, isotonic solutions, and surfactants are added to meet these requirements.

1. Eye drops:
Eye drops are sterile aqueous or oily solutions or suspensions intended for instillation
into
The conjunctiva sac. They usually contain drugs having antiseptic, anti anaesthetic and
inflammatory,
Mydriatic, miotic properties.
Ear drops:
Ear dropsare aqueous or oily solutions or suspensions of one or more medicaments
intended for instillation into the outer ear.
Nasal drops:
Nasal drops are aqueous or liquid paraffin solutions meant for instillation into the
nostrils. Nasal drops often contain vasoconstrictor drugs to relieve nasal congestion.

2. Composition of eye, ear and nasal drops:
Active ingredients
Vehicle
Anti microbial preservatives
Adjuvant
Suitable container for administration

3. Eye, ear and nasal drops should possess following properties:
-Foreign particles
- sterility
- pH
- tonicity
- viscosity
- surface activity
- foreign particles

4. Foreign particles:
All products should be clear and free from:
-Foreign particles, fibers and filaments
- these solutions should be clarified very carefully by passing through bacteria proof
filters such as membrane filters, sintered glass filters

5. Sterility:
Dry heat sterilization at 160 0c for 2 hrs is employed for non aqueous preparations suchas liqu
Autoclaving at 1150c for 30min or 1210c for 15min
Viscosity:
Inorder to prolong the contact time of the drug in the eye, various thickening agents are adde
Commonly used thickening agents are:
Poly vinyl alcohol (1-4%)
Polyethylene glycol
Methyl cellulose

6. Tonicity:
All the products should be isotonic with lachrymal secretions to avoid discomfort and
irritation. Commonly used agents are:
0.5 – 2% NaCl
1.9% boric acid
Sodium acid phosphate buffer
pH of the preparations:
pH plays an important role in therapeutic activity, solubility, stability and comfort to the
patients.
Ear drops pH 6-7
Eye drops pH 7.4
Nasal drops pH 5.5 – 7.5

7. Surface activity:
Vehicles used in opthalmic preparations must have good wetting ability to penetrate cornea
Certain surfactants or wetting agents added which are suitable for opthalmic products
Commonly used surfactants are:
Benzalkonium chloride
Polysorbate 20
Polysorbate 80
Doctyl sodium sulphosuccinate