Ophthalmic Medications
By George J. Malmberg, RPh, FACA
Basic Information
Compounded ophthalmic formulations for veterinary patients
are used more often than ever before. Prepared in a dedicated cleanroom
according to strict regulations for sterile compounds, their ingredients,
strength, and dosage form can be individualized for the treatment of the
diseased or injured eye. Common ocular diseases treated with compounded
medications include:
• Canine keratoconjunctivitis
• Canine chronic superficial keratitis (pannus)
• Canine topic blepharoconjunctivitis
• Canine glaucoma
• Feline herpetic keratitis
• Conjunctivitis and viral ophthalmic conditions
in a variety of species
• Equine keratomycosis
• Ocular manifestations of Bartonella henselae
in cats
Although most compounds used to treat ophthalmic disease
in veterinary patients are applied topically, compounded oral medications
are also prescribed.
When to Prescribe Compounded Ophthalmic Medications
Veterinary practitioners diagnose and treat numerous
ophthalmic conditions. More difficult cases are usually referred to a
veterinary ophthalmologist for treatment. Most veterinary ophthalmologists
are members of the American College of Veterinary Ophthalmologists or
the American Society of Veterinary Ophthalmologists.
Compounded medications are prescribed when:
• The best therapy for a patient is not commercially
available.
• The active drug ingredient is not available in
the desired strength or dosage form.
• A commercial product is on extended backorder.
• A commercial product has been discontinued by
the manufacturer for non-safety reasons.
• Patient/owner compliance may be improved and
stress reduced through the use of pet-friendly flavoring and alternative
dosage forms, resulting in better patient outcomes.
• A new therapy reported in the veterinary literature
is not available commercially.
• Special flavorings are required for oral medications.
• Dye-free or preservative-free topical formulations
are necessary.
Effective Dosage Forms
The most common dosage forms for topical veterinary
ophthalmic medications are solutions, suspensions, ointments, and gels.
These dosage forms are all within the capability of a knowledgeable compounding
pharmacist with the appropriate equipment (discussed under Due Diligence).
Each dosage form has unique formulation considerations.
Ophthalmic Solutions are one of the most frequently used dosage
forms. Considerations when formulating a solution include solubility of
the formula ingredients, clarity, tonicity, buffers, pH, sterility, and
appropriate selection of preservatives when indicated. The most common
vehicle for solutions is water; however, there are oil solutions of select
chemicals.
Ophthalmic Suspensions are generally prescribed for medications
that are not water-soluble. They are usually aqueous suspensions of the
active ingredient. Particle size and the selection of a suspending agent
are important when compounding an ophthalmic suspension. The particles
in the suspensions must be small and uniformly suspended after shaking.
Additional considerations are pH, sterility, and preservatives.
Ophthalmic Ointments and Gels are solid dosage forms utilizing
either the more common white petrolatum vehicle or the newer aqueous methylcellulose
gel. Compounding considerations for gels include insuring a small, uniform
particle size for a non-gritty, non-irritating product. Additionally,
sterility and the selection of a preservative, if needed, must be considered.
All dosage forms must then be packaged in an appropriate container. The
packaging of veterinary ophthalmics must be sterile as well as protect
the active drug and facilitate administration. There are a number of options
available including amber glass dropper bottles or an opaque plastic droptainer
to dispense solutions and suspensions and tubes with ophthalmic applicator
tips for ointments and gels.
Due Diligence Considerations
Not every pharmacy has the equipment, qualified staff,
or facilities necessary to perform sterile compounding. The veterinarian
who prescribes any preparation bears responsibility for the outcome of
treatment and must exercise due diligence in selecting a compounding pharmacy.
At a minimum, the pharmacy should have a Class 1000 Cleanroom with a Class
100 Laminar Air Floor Hood or a Glovebox/Isolator to provide a sterile
environment. This equipment should be independently certified biannually.
Additional equipment such as sterilization filters, pH meters, micronizers,
autoclaves, and ointment mills are also used by the pharmacist to prepare
quality pharmaceutical preparations. Pharmacists should be familiar with
veterinary compounding in general and veterinary ophthalmic compounding
in particular. Compounding personnel should be trained and validated in
aseptic technique according to USP guidelines. Quality control evaluations
that include weight, volume, pH, visual inspection, post-filtration integrity
testing, and sterility testing should be performed on all batches of ophthalmic
preparations. Documentation should be extensive and allow for the tracing
of any dispensed medication back to the formulation worksheet and ingredient
lot number. After the above criteria are met, other factors such as turnaround
time and quality customer service, membership in professional organizations
such as the American College of Veterinary Pharmacists, and attendance
at veterinary ophthalmology meetings should also be considered when a
compounding pharmacy is selected to prepare ophthalmic preparations.
Compounded medications offer an excellent alternative
for many ophthalmic patients.
About the Author
 George
J. Malmberg is a registered pharmacist. He graduated from the University of
the Sciences in Philadelphia, College of Pharmacy in 1972. Mr. Malmberg has
participated in courses in advanced compounding and advanced sterile compounding
and clean room techniques.
He is a member of several professional associations, including
the American Pharmaceutical Association and the International Academy of Compounding
Pharmacists.
Mr. Malmberg is a fellow of the American College of Apothecaries
and the American College of Veterinary Pharmacists. He has served on the editorial
advisory board for the International Journal of Pharmaceutical Compounding,
and as an adjunct faculty member and clinical instructor at the USP College
of Pharmacy. Mr. Malmberg was awarded the Albert E Rosica, Jr. Memorial Award
in 2000 for outstanding contribution to pharmacy education.
The information contained on this site
is general in nature and is intended for use as an informational aid. It does
not cover all possible uses, actions, precautions, side effects, or interactions
of the products shown, nor is the information intended as medical advice or
diagnosis for individual health problems or for making an evaluation as to the
risks and benefits of using a particular product. You should consult your doctor
about diagnosis and treatment of any health problems. Information and statements
have not been evaluated by the Food and Drug Administration ("FDA"),
nor has the FDA approved the products to diagnose, cure or prevent disease.
Wedgewood compounded veterinary medicines are not
intended for use in food and food-producing animals.
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