State of the art in the standardization of herbal extracts

Introduction: The increase in the use of medicinal plants has been evidenced in recent decades throughout the world, mainly as plant extracts with therapeutic purposes. To guarantee the quality and efficacy of these extracts, guidelines, and regulations have been established with the purpose to reduce the variability of obtaining processes and ensure their standardization. Aim: To compile current data on the main parameters and methodologies for the standardization of plant extracts and their definition. Methodology: World Health Organization guidelines, Pharmacopoeias and PubMed, Google Scholar, Science Direct, and EBSCOHost databases were used to collect information about extract standardization. The documents were selected according to their publication date (1981–2020), using keywords in English such as “standardization of plant extracts”, “standardization of methodologies” and “guidelines for obtaining standardized products”. Results: Pharmacopoeias and guidelines of the World Health Organization are the main literature that supported the methodologies for standardization, as well as the limits of parameters related to the quality control of plant extracts. The main parameters established were macro and microscopic evaluation of plant material, foreign matter, ash content, water content, chromatographic analysis, biological analysis, and qualitative and quantitative chemical evaluation. Conclusions: The main guide documents for the standardization of plant extracts are generally accepted by most regulatory agencies in different countries and determine guidelines related to the physicochemical, biological, and analytical chemical characteristics of plant material and extracts.