Diagnostic Ophthalmic Agents 1 Flashcards
Type of ophthalmic unit that is only used one time
single-dose unit (SDU)
Why are you able to only use Single-dose units once?
They do not stop microbial growth because they are preservative-free.
How much medication does a single dose vial hold?
0.4-0.8 mL/vial
Type of ophthalmic unit that is intended for repeated use
Multiple dose preserved unit and Multiple dose preservative free unit (MDPF)
Why are you able to use the multiple dose (preserved) units more than once? What is the benefit of this?
It contains preservatives that have an antimicrobial action that rapidly limits growth and kills microorganisms.
This benefits in increasing shelf life.
What are some common preservatives in multiple-dose bottles?
Benzalkonium chloride (BAC or BAK), polidronium, polyhexylmethylbiguanide (PHMB), chlorhexidine, thimerosal (contains mercury)
How are some multiple dose bottles able to not have preservatives in them?
They contain a one-way valve that dispenses one sterile drop only which closes after each use. Also has a filter that protects the solution from airborne microorganisms.
What are some examples of multiple-dose preservative-free products?
ClearEyes Pure Relief
RESTASIS MultiDoseTM
Oasis Tears PF
Refresh Relieva PF
hydraSense drops
What are the 7 types of ophthalmic formulations?
1) Ophthalmic solution
2) Ophthalmic suspension
3) Ophthalmic gel
4) Ophthalmic emulsion
5) Ophthalmic ointment
6) Ophthalmic dye
7) Ophthalmic preparation
What ingredients do ophthalmic solutions contain?
aqueous solution that contains saline, buffering salts, and polymers
What do buffering salts do in ophthalmic solutions? What is the shelf life?
Maintain pH from 5.0 to 8.0. Makes the patient more comfortable when the drop is received. The shelf life is 2 years which is long.
Period between date of manufacture (DOM) and use-by date
shelf life
What’s the purpose of polymers in ophthalmic solutions?
They increase the viscosity which makes solution last longer on the corneal surface.
Commonly used polymers in ophthalmic solutions
-cellulose derivatives
-polysaccharides (sodium hyaluronate or gellan gum)
-carbomer (crosslinked poly(acrylic acid)) -polyvinyl alcohol
-poloxamers
(poly(ethylene oxide)-poly(propylene oxide) block copolymers)
What ophthalmic formulation gives a milk appearance and contains solid particles dispersed in solute?
Ophthalmic suspension
What does an ophthalmic suspension contain solid particles dispersed in the solution?
It increases contact time when on the eye.
What must you do before dispensing an ophthalmic suspension?
Shake the bottle because solid particles need to be re-dispersed into the liquid
How big are the particles in a suspension?
<10 microns
Not big enough to irritate the surface fo the eye
What ophthalmic formulation is a highly viscous solution with a saline aqueous base and mucoadhesive polymer?
Ophthalmic gel
What attaches an ophthalmic gel to tissue?
bioadhesion
One advantage and one disadvantage of using ophthalmic gel
Advantage: Increases contact time on surface of eye/tissue.
Disadvantage: Blurs vision temporarily
What ophthalmic formulation is prepared by dissolving active ingredient into oil phase, then emulsifying agents and water vigorously to form a uniform water-in-oil emulsion
Ophthalmic emulsion
What ophthalmic formulation is prepared by dissolving active ingredient into oil phase, then emulsifying agents and water vigorously to form a uniform water-in-oil emulsion?
Ophthalmic emulsion
Process in ophthalmic emulsions that reduces oil droplet size to sub-micron size to stabilize droplet
Homogenation process
Does an ophthalmic emulsion preparation separate into its different components after letting it sit?
No
What appearance does an ophthalmic emulsion have?
Milky appearance
What ophthalmic formulation is a non-aqueous preparation of emollient fats?
Ophthalmic ointment
Describe how ophthalmic ointments interact with water or saline.
Not generally immiscible so it does not form homogenous mixture.
The melting point of ophthalmic ointments
Near body temperature
What has the longest contact time of the ophthalmic formulations?
Ophthalmic ointments (2-4x longer)
What ophthalmic formulation is a dried strip that must be wet with saline to be able to be applied to the eye?
Ophthalmic dye
What is an ophthalmic prescription?
Prescription for eye; must request sterile ophthalmic preparation to be used in or around eye. Sterile by law.
When applying a drug to the eye, ___% active drug is absorbed into cornea and conjunctiva
5%
What percent of the drug goes into aqueous humor?
1%
What percent of the drug is delivered to the nasolacrimal duct or wiped from the surface?
95%
What do you need to confirm before instilling the drug?
Brand Name
Concentration
Expiration Date
How do you document a drug that you are instilling?
- Drug name and concentration
- # of drops instilled
- Time of instillation
How long should a patient close their eye after instilling an ointment?
1 minute
How long would you hold punctal occlusion for?
1-3 minutes
How long would the patient close their eyes when doing passive lid closure?
1-3 minutes.
