Topic overview

Start with the big picture

Evaluation begins with organoleptic and macroscopic comparison of a crude drug’s visible and sensory features with expected characteristics; microscopy can then reveal diagnostic structures or foreign material. Physical constants and chemical assays help assess quality and marker-compound content, while chromatography and spectroscopy provide profiles or signals that can indicate substitution, impurities, or variation. DNA barcoding and immunoassays support species authentication, and bioassays assess expected activity. Safety-focused testing addresses contaminants such as heavy metals, pesticides, aflatoxins, and microbes. Microchemical reactions, fluorescence, volatile-oil evaluation, isotope analysis, and digital image methods extend the toolkit. Together, these approaches provide complementary evidence rather than relying on one test alone.