Beyond use dating
Direct extrapolation of the information to the specific compounded formulation requires that the scientific study data utilize the same drug source, the same drug concentration, and the same compounding procedures, stores the formulation in the same container, and has subjected the formulation to the same anticipated environmental variables.
A growing number of reference sources contain stability information, and the pharmacist should have ready access to this material. Many times the published references do not evaluate exactly the same formulation, or the study did not examine the stability for a long enough period of time.
Seems the revised BUD guidance gives some credence to preservatives, sterilization methods, etc, but with a maximum BUD of 45 days.
Do you feel the USP revision, coming out the end of next year, will allow for extended BUD’s for 503A pharmacies with adequate references/testing?
One recent story, the compounding pharmacy Imprimis that made curcumin in PEG 40 castor oil; they weren’t using USP grade and degraded (no stability study done on this obviously).
Polyethelyne Glycol degrades to Diethylene glycol which is a great solvent but basically starts shutting down biological systems (liver kidney) in humans.
In addition, federal and state (NC) regulations require that the following information appear on the label.
If the manufacturer cannot assist in assigning a beyond use date, the next step is to obtain published stability information from reference books or the primary literature.
However, reliable, published stability information is sometimes lacking for many types of drugs.
In these instances, pharmacists should consult with the drug's manufacturer to establish a beyond use date.
Beyond use dates are different from expiration dates.
Expiration dates are required on commercially manufactured products and are determined after extensive study of the product's stability.
I recently received a question from another pharmacist: “I wanted to get your thoughts on the current proposed revised USP standard.