Essential Pharmacy Compounding (EPC) would like to welcome you to the Feline Compounds site for veterinarians and staff.
EPC can help determine if a medication is appropriate for transdermal use, and provide a spreadsheet containing information about common medications that could be used with transdermal delivery.
The ideal transdermal (TD) medication should be:
- Non-irritating to the skin
- Have a low molecular weight (less than 400 g/mol is ideal)
- Have a low melting point ( < 200°C) for increased solubility in skin lipids
- Have a relatively high (but balanced) partition coefficient (logP of 1-3)
- Adequately soluble in oil and water.
Typical volume is restriced to 0.05 - 0.1 ml rarely exceeding 0.15 ml. Ideal concentrations are not to exceed12.5mg/0.1ml to maintain properties of transdermal formulation. For determination of transdermal dosing, available injectable dosages should be referenced first and assume 100% bioavailability; if injectable dosing is unavailable, oral dosage comparision may be utilized. The vast majority of provided transdermal formulations are anhydrous and according to United States Pharmacopeia compounding standards are assigned a Beyond Use Date of no longer than 180 days stored at room temperature. Be assured by our policy which limits the day supply of no longer than 90 days and refrigeration of certain formulations to alleviate solubity and stability concerns.