USP Salt Policy (December 2014)
FDA Drug Info Rounds pharmacists discuss the application of the United States Pharmacopeia’s Monograph Naming Policy for Salt Drug Substances in Drug Products and Compounded Preparations (USP Salt Policy) by FDA’s Center for Drug Evaluation and Research.
Host: Captain Mary Kremzner
Pharmacist #1: Captain Catherine Chew
Pharmacist #2: Lieutenant Lindsay Davison
Captain Kremzner: The topic of today’s discussion is the application of the United States Pharmacopeia’s Monograph Naming Policy for Salt Drug Substances in Drug Products and Compounded Preparations by FDA’s Center for Drug Evaluation and Research, or CDER. For the purposes of this presentation, we will refer to this policy as the USP Salt Policy. This Policy became effective on May 1, 2013. CDER has been working with USP on this policy for many years, and is now applying this policy to prescription drug products.
Hi, I’m Captain Mary Kremzner and this is Drug Info Rounds, brought to you by the pharmacists in FDA’s Division of Drug Information.
First, let’s outline the details of the USP Salt Policy. Captain Chew?
Captain Chew: The USP Salt Policy is a naming and labeling policy that applies to drug products that contain an active ingredient that is a salt. CDER is now applying this policy. For pharmacists, this means:
- When the FDA approves the new labeling for a new product that contains a salt as an active ingredient, that the drug name and strength will be expressed in terms of the active moiety rather than the salt. The active moiety is the molecule or ion responsible for the physiological or pharmacological action of the drug substance. It excludes the portions of the molecule that cause the drug to be an ester, salt, or other non-covalent derivative.
- The strength will be expressed in terms of the active moiety.
- When the name and strength are expressed in terms of the active moiety, the full name and full strength of the active ingredient, or salt, also must appear elsewhere on the drug product labeling, as this information may be useful to practitioners and patients. Here is an example that may be found in the “Description” section of the labeling of the fictitious drug ‘Miracle Drug Capsule’:
Lieutenant Davison: This Policy applies only to new FDA-approved prescription drug products. If there are retrospective name changes, USP and FDA have agreed to work together. CDER is separately considering application of the Policy to over-the-counter and biological products.
Captain Chew: Under specified circumstances, the name of the salt will be retained if it conveys vital information from a clinical perspective. For a newly approved drug product, if the salt is included in the name, you should read the labeling to learn why. It may be because the administration of the entire salt is therapeutically important, such as with lithium carbonate. It may be because the salt may affect the drug pharmacokinetics. Or it may be because the product contains a specific electrolyte such as sodium or potassium which may be of clinical significance in special populations.
Lieutenant Davison: As the USP Salt Policy is applied, CDER may make additional exceptions when retention of the name of the salt is appropriate for safety or historical reasons.
If CDER grants an exception request to allow the salt to be part of the product’s name, then the product’s strength will be expressed as that salt and the labeling will include an equivalency statement to indicate the amount of active moiety present.
Here is an example of a product label of a drug that contains an active ingredient that is a salt. The new language adds the information about the salt in parentheses. It states that each capsule contains 10 mg of New Drug and in parentheses states (equivalent to 10.5 mg New Drug Hydrochloride USP).
Captain Kremzner: This Policy is very important to pharmacists. Will you describe why?
Captain Chew: CDER’s application of the USP Salt Policy should help to avoid medication errors that could result from a mismatch of nonproprietary name and strength. There have been reports of confusion and medication errors as a result of not understanding that the strength was in terms of the active moiety, and incorrect doses have been administered. Requiring the name and strength to match on the label and including an equivalency statement will help to reduce such errors.
In addition, the policy will make it easier for pharmacists to calculate an equivalent dose when transferring patients from one dosage form to another even if the products contain active ingredients that are different salts, because the strengths and names will be based on the active moiety.
Remember that two products with the same name do not necessarily contain the same salt. When deciding to substitute one product for another, the pharmacist is responsible for knowing if it is appropriate to do so. This will involve determining if the products contain the same active ingredient (or salt), which is why the information is available in the equivalency statement.
Captain Kremzner: Thank you both for explaining this significant policy change. You may read more about the USP Salt Policy in FDA’s Manual of Policy and Procedures. If you have questions about the Policy, call or email FDA’s Division of Drug Information.