Letter to the Editor: Glen Jon Smith

This is in response to the article titled, “GSK Study Questions Bioequivalency of Generic Cold Sore Creams” in Pharmaceutical Technology, January 2006, page 22.

It is important to note that the referenced article, L. Trottet, “Are All Aciclovir Cream Formulations Bioequivalent?” Int. J. Pharm. 304 (1–2), 63–71 (2005), is a study comparing the GlaxoSmithKline (GSK) innovator product to European generic acyclovir creams. No comparison and reference to US generic products was made in the article. In fact, there are currently no FDA approved generic acyclovir creams. The discussion in the article may lead readers to conclude that US generic products are inferior to innovator products when in fact the products compared were not approved or available in the United States.

Further, the last paragraph states, “FDA requires that the innovator drug and the follow-on biologic must be therapeutically equivalent…” Drug products and biologics are different types of products. The use of the term “follow-on biologic” is confusing to readers. The article cited regarding the role of reverse engineering discusses the importance of a correct formulation for generic drug performance and does not discuss biologics. It would have been correct if the January Pharmaceutical Technology article stated, “FDA requires that the innovator drug and the generic drug be therapeutically equivalent, which includes both bioequivalency and pharmaceutical equivalency.”

Generic drug products approved in the United States meet very high standards of quality and are deemed equivalent to the innovator. Articles that do not make clear that they are discussing products from outside of the United States are confusing to the public.

Glen Jon Smith

Center for Drug Evaluation and Research