Eliminating Analytical Ambiguity in the Scientific Study, Development and Quality Control of Natural Health Products and Dietary Supplements

Recent surveys have shown that upwards of 71% of Canadians consume natural health products (NHPs) either on a daily or seasonal basis [1] and 73% of American adults surveyed reported taking some type of non-prescription vitamin, dietary supplement or mineral supplements over the course of a year [2]. The prominence of these products in the health care setting is further buoyed by the current deluge of adverse drug effects in conventional medicines. Yet 48% of Americans surveyed believe supplements are not adequately tested [3] and 46% of Canadians agree that a lot of claims made by NHP manufacturers are unproven [1]. In 2002, the World Health Organization attributed problems related to Traditional Medicines, including poor quality research, to a paucity of sound methodology and short-supply of resources [4]. A fundamental scientific flaw of much of the clinical research on botanical-based products has been the failure to characterize the study material, an omission that renders resulting data meaningless [5,6]. Adequately validated methods are an essential prerequisite for producing fair, objective evaluations. A shared feature of CGMP for NHPs and Dietary Supplements is establishment and demonstration of conformity to specifications for identity, purity, and content of defined attributes. This system disintegrates if the analytical methods employed to ensure products meet specifications are not fit for their intended purpose, i.e. validated. A validation study is the scientific process for demonstrating that a test is transferable and will reliably deliver the correct or “true” analytical value. The ICH and U.S. Law (Federal Register 60:11259–11262) mandate determination of accuracy, precision, specificity, detection limit, quantitation limit, linearity, and range of any test used for determination of conformity to content (assay) specifications. This review will explore the role of validation and show how failure to properly validate test methods impacts both scientific study and product quality in the marketplace. References: [1] Ispos Reid for Health Canada. Baseline Natural Health Products Survey Among Consumers Final Reported Submitted to Health Canada March 2005. Available at http://www.hc-sc.gc.ca/dhp-mps/alt_formats/hpfb-dgpsa/pdf/pubs/eng_cons_survey-eng.pdf. Accessed August 30th, 2006. [2] Timbo BB, Ross MP, McCarthy PV, Lin CTJ. (2006) J Am Diet Assoc, 106(12): 1966–1974. [3] Blendon RJ, DesRoches CM, Benson JM, Brodie M, Altman DE. (2001) Arch Intern Med, 161(6): 805–810. [4]World Health Organization. Traditional Medicine Strategy (2002–2005). Available at http://www.who.int/medicines/publications/traditionalpolicy/en/. Accessed August 30th, 2006. [5] Gagnier JJ, Boon H, Rochon P, Moher D, Barnes J, Bombardier C. (2006) Ann Intern Med, 144(5): 364–367. [6] Wolsko PM, Solondz DK, Phillips RS, Schachter SC, Eisenberg DM. (2005) Am J Med, 118(10): 1087–1093.