Author Affiliations: Lake Erie College of Osteopathic Medicine School of Pharmacy, Erie, Pennsylvania.
After reading the article by Cantrell and colleagues1 on the stability of active pharmaceutical ingredients (APIs), we believe it is necessary to comment on some apparent oversimplifications in the article. The term potency is equated with API concentration, which is reasonable only if given a properly stored, well-understood formulation prior to its expiration date. While all of the long-expired medications were in a solid dosage form, it is worthy to note that the compounds tested would show great temperature dependence in their stability as described in Q10 testing.2 Complications arise with issues such as (1) unintended polymorphic transitions, (2) hydrate formation, (3) dehydration, (4) thermal decomposition, and (5) photoreactivity, to name a few.3 Moreover, the authors did not address issues associated with solid-state chemistry potentially affecting in vivo dissolution and consequently absorption, nor did they conduct standard dissolution testing.
Madden MM, Etzler FM, Gant T. Comment Regarding the Stability of Active Ingredients in Long-Expired Prescription Medications. JAMA Intern Med. 2013;173(11):1034-1035. doi:10.1001/jamainternmed.2013.409