Is the biopharmaceutical quality of extracts adequate for clinical pharmacology?

According to definition, an extract is a multi-substance mixture from a medicinal plant obtained by extraction of specific parts of the plant. Corresponding to the active ingredients in each case, each extract exhibits, qualitatively and quantitatively, a specific content spectrum, so that an extract is not just any extract. With an increasing demand for demonstrating the clinical efficacy of plant-based substances, extracts or extract fractions, we necessarily confront the problem of phytogenerics, i.e. extract-identical preparations for exchange versus the innovator. Up to now, pharmacognosic experts, phytochemists, and pharmacists have dealt with the problem as to the bioequivalence of phytopharmaceuticals within the context of pharmaceutical and biopharmaceutical/technological equivalence. In the meantime, however, from a number of plant extracts, the active ingredients determining their efficacy are known and analytical methods have been established, so that bioavailability/bioequivalence studies similar to those for chemical/synthetic substances are now possible.