Formulation - Ophthalmic preps

Question 1

Do eye lotions contain a preservative?

Answer 1

Multidose containers contain a suitable antimicrobial preservative at appropriate concentration
If not prescribed with a preservative product, it should be supplied as a single dose container

Question 2

What is an ocular insert?

Answer 2

Sterile, solid or semi-solid preparations of suitable size and shape, designed to be inserted into the conjunctival sac to produce an ocular effect
- elliptically shaped units with a core reservoir of drug surrounded by a diffusional membrane
- diffuses drug into tear fluid

Question 3

What is the purpose of an ocular insert?

Answer 3

Used to achieve prolonged release of drugs into the eye
- e.g. to treat glaucoma

Question 4

Give an example of an ocular insert

Answer 4

Ocusert

Question 5

How are ocular inserts packaged?

Answer 5

Individually distributed into sterile containers
- means must be taken to ensure a suitable dissolution behaviour

Question 6

Give examples of ocular injections that can be given

Answer 6

Retrobulbar
Intracorneal
Intravitreous
Subconjunctival

Question 7

What are the categories of ophthalmic drug preparations?

Answer 7

Cycloplegics
- atropine sulphate
- tropicamide
- paralyses ciliary muscle
- accomodation (focus)
Mydriatics
- tropicamide
- dilates pupil
- can examine the back of the eye
Miotics
- pilocarpine
- constricts pupil
- opens drainage channels

Other diagnostics
- stains
- fluorescein
- aids in diagnosis of eye problem
Surgical adjuvants
- local anaesthetics
- lignocaine
- used during surgical procedure

Anti-inflammatories
- NSAIDs
- antihistamines
- corticosteroids
- reduces inflammation

Anti-infectives
- antibacterials
- chloramphenicol
- fusidic acid
- antivirals
- aciclovir
- antifungals
- nystatin
- treats infection

Anti-glaucoma
- miotics
- beta-blockers
- timolol
- reduces intraocular pressure
- reduces rate of production of aqueous humour
- increases rate of uvoscleral outflow
- increase outflow through trabecular network

Miscellaneous
- artificial tears
- hypromellose
- liquid paraffin

Question 8

What is the ideal situation to reduce contamination when using ocular preparations?

Answer 8

Separate containers for each eye
Single dose if high risk of infection
Discard 7 days after opening
Discard following surgical procedure
Fresh supplies at discharge from hospital
Sterile applicators for eye ointments