Sterile Compounding : Veterinary
Injectables | Ophthalmics | Erectile Dysfunction | Veterinary
Examples of sterile veterinary preparations that can be compounded by prescription order include:
- Methocarbomol
- Mitomycin C
- Guaifenesin
- Methylene Blue*
- Ophthalmic Preparations*
*see more info below
Ask us about combinations to meet specific needs or medications that are currently unavailable or have been discontinued for non-safety reasons (such as when a newer therapy reduces the need and therefore decreased use results in the medication no longer being profitable to manufacturer).
Methylene Blue for Drought-Affected Animals
The exceptional drought that is currently plaguing many areas in the United States has caused many problems for livestock producers and their stock. The drought is also exceptional in that it is forcing many veterinarians and pharmacists to consider use of the chemical agents listed in Appendix A in the FDA’s Compliance Policy Guide for Compounding of Drugs For Use in Animals. The appendix - which lists ammonium molybdate, ammonium tetrathiomolybdate, ferric ferrocyanide, methylene blue, picrotoxin, pilocarpine, sodium nitrite, sodium thiosulfate, and tannic acid - represents the most effective antidotes used to treat livestock poisoning.
In conditions of drought, plants are no longer able to convert nitrogen to proteins. When livestock graze on nitrogen-saturated plants, they not only suffer from inadequate protein intake, but also become nitrate poisoned. Sheep, goats and cattle intoxicated with nitrate exhibit signs of labored breathing, staggering gait, and sudden death, all of which are due to oxidative injury to hemoglobin, leading to methemoglobinemia and hypoxia. If not treated, these animals will functionally suffocate, even while breathing air.
While it is generally a good idea to steer clear of compounding for food animal patients, compounding pharmacists can literally save hundreds of animal lives by compounding methylene blue 1% injection for nitrate poisoned livestock. Solutions of methylene blue powder and sterile water are easily autoclaved in 500ml plastic, autoclavable serum bottles, which is the average volume required to treat an adult cow suffering from nitrate poisoning. For more information on methylene blue treatment of nitrate toxicity in livestock, see Nitrate and Nitrite Poisoning: Introduction, in the Merck Veterinary Manual, Merck & Co., Inc., Whitehouse Station, NJ, 2006.
Veterinary Ophthalmic Preparations
Many agents used in veterinary ophthalmology are no longer or never were commercially available. Examples of agents that are commonly used by veterinarians but are no longer commercially available currently include oxytetracycline ophthalmic ointment, idoxuridine ophthalmic solution and ointment, vidarabine ophthalmic solution, miconazole solution, trifluridine ophthalmic solution, tetracycline ophthalmic solution, rose bengal solution, and chloramphenicol ophthalmic ointment. Even if commercially available, products may be of inappropriate concentration to achieve a therapeutic effect in a given patient (e.g. cyclosporin A) or may have agents and excipients that have adverse effects in animal patients (e.g. neomycin sulfate in cats). In other cases, no product is commercially available and the needed preparation must be compounded from other non-ophthalmic drugs or from bulk chemicals (e.g. acetylcysteine ophthalmic solution and disodium edetate ophthalmic solution). For these reasons, pharmacists are frequently called upon to compound sterile preparations for use in the animal eye. To ensure adequate stability, uniformity, and sterility, both the American Society of Health-Systems Pharmacists and the United States Pharmacopoeial Convention have published guidelines for pharmacy-prepared ophthalmic preparations. These guidelines address the following areas of concern:
- Validation of Formulation
- Documentation
- Sterility and use of Preservatives
- Clarity
- Tonicity
- Viscosity Enhancers
- Quality Control
- Packaging
- Expiration Dating
- Considerations for use of ophthalmics in veterinary patients
- General Principles of ocular penetration
- Corneal penetration
Key points for corneal penetration of drugs:
- lipophilic
- equilibrium between ionized and non-ionized forms
- small molecular weight (<350)
- high local concentrations
Intravitreal penetration
Topical Mitomycin C Adjunct Therapy for Equine Ocular Squamous Cell Carcinoma
During surgery for SCC, many equine ophthalmologists also treat the eye with a topical solution of mitomycin C at a concentration of 0.4mg – 4mg/ml applied to the eye for 1-5 minutes.1 Following surgery, some clinicians will apply mitomycin C 0.4mg/ml topical solution to the affected eye three times daily for 7 days in repeating cycles until tumor resolution. Mitomycin C is a potent anti-neoplastic, cytotoxic agent and should be handled and disposed of accordingly.
1 Aust Vet J. 2006 Jan-Feb;84(1-2):43-6.
The use of mitomycin C as an adjunctive treatment for equine ocular squamous cell carcinoma.
Click here to access the PubMed abstract of this article.
