FEATURE AND USES OF OPHTHALMIC OINTMENTS AND GELS

OPHTHALMIC OINTMENTS

• Application of medication to the eye or conjunctival sac effects the surface of the eye and underlying tissues as the drug penetrates. 

• Provide extended residence time on the surface of the eye, increasing the duration of their surface effects and bioavailability for absorption into the ocular tissues. 

• Cleared from the eye as slowly as 0.5% per minute, compared with solutions, which can lose up to 16% of their volume per minute.

Ointment base for ophthalmic ointment

• Must not be irritating to the eye.

• Must permit the diffusion of the medicinal substance throughout the secretions bathing the eye. 

• Should have softening point close to body temperature, both for comfort and for drug release

Mixtures of white petrolatum and liquid petrolatum (mineral oil)

are used as medicated and unmedicated (lubricating) ophthalmic ointments.

Lanolin

added as water absorbing.

PEG (gel base) and mineral oil

permits water and water -insoluble drugs to be released within the base.

Medicinal agents

added to an ointment base either as solution or as a finely micronized powder.

fine milling

The ointment is made uniform and smooth by ___

• Dry heat sterilization

• Bacterial filtration

Rendering an ophthalmic ointment sterile requires special technique and processing:

• Methylparaben (0.05%) 

• Propylparaben (0.01%) 

• Phenylmercuric acetate (0.0008%) 

• Chlorobutanol (0.5%) 

• Benzalkonium Chloride (0.008%)

When antimicrobial preservative is needed:

collapsible ointment tubes

• USP directs that ophthalmic ointments must be packaged in _____ having elongated narrow tip (should be held slightly above the inside portion of the sack between the lower eyelid and eyeball)

• Without touching the tip to any part of the eye, a thin ribbon ointment, approximately 0.25 to 0.5 inch, should be placed along the inside of the lower lid.

Application

• The patient should face down and slowly close the eye for a few second. 

• Any excess ointment should be wiped from the eyelids and lashes with a clean tissue.

• After use, the ointment must be capped quickly and tightly.

Patient Counseling

• Patient should be advised that blurred vision will occur as the ointment spreads over the eye and not to be alarmed.

• If ointment is to be administered only once daily, it is often preferable to do so at bedtime, when vision impairment will be inconsequential.

• It is important to emphasize that ocular products if handled improperly can become contaminated by bacteria that cause ocular infections, which may lead to serious consequences. 

• Must avoid touching the tip of the tube to the eye, eyelid, finger-tip, or any other surface,