I talk to veterinarians every week who want to know what concentrations to prescribe for their compounded medications. Delivering the right dosage is essential to your patients recovering swiftly and completely. There are several factors to take into account when considering compounded medication, including its strength and volume of the medication and how that can affect your patient. Part of my job is to ensure that the volume of the medication is not to large or small, and that the ideal volume has been prescribed based on the patient it’s intended for.

What Happens When the Medication Volume Is too Large?

This can result in your patient not receiving a high enough dose of their prescription, which can be dangerous to their health. The concentration of the medication can be increased by reducing the amount of filler that is utilized to deliver the Active Pharmaceutical Ingredient (API). This can be achieved by utilizing a larger tablet that contains proportionally less filler. When the tablet cannot be utilized, the concentration can also be increased by utilizing the API available in the powder form that does not contain fillers.

What Happens When the Medication Volume Is too Small?

When medication requires a dose that’s too small to adequately measure, you risk giving your patient an inaccurate dose and increase the risk of toxicity. The concentration of the compound can be lowered by diluting the medication. Diluting a compound in this manner typically requires highly accurate scales—preferably you’ll want to measure with certified scales. Sometimes the medication cannot be diluted from the available form, such as when the tablet has a special coating for extended release. If this is the case, the medication may be prepared from the API directly.

How Does Medication Concentration Affect Solubility?

A medication’s concentration can negatively affect solubility if you’re not careful. When the concentration of a medication is too high, it becomes very difficult to evenly mix. An unevenly mixed compound can lead to inaccurate dosing and, therefore, ineffective or toxic scenarios for your patient. It’s best to remain cautious when approaching the solubility limits of the medication. Instead of risking an inaccurate dosage, it may be best to either dose less of the medication more frequently or find an altogether different alternative. Compounding from commercial forms can lead to less accurate potency than compared to if the API is utilized. (The pros and cons of compounding from API will be discussed in the near future). To limit this risk, be sure to only utilize API from an FDA registered supplier that has a corresponding certificate of analysis to identify purity values.

Finding the Ideal Dosage

To avoid having to dilute or re-mix a medication, first calculate your patient’s ideal volume, and then determine the needed concentration. This will help you determine if reaching the desired concentration is safe, or even feasible. If it is not possible to reach the needed medication concentration in your patient’s required volume, then you must find an alternative course of treatment.

To learn more about the effects of medication concentration on your patients, contact EPC at 888-733-0300 (ext 3) to speak with one of our compounding specialists. They will be able to help you determine if your dosing will be accurate with the determined concentration.