Evaluation of the dissolution behaviour of some commercial herbal drugs and their preparations

Dissolution rates are routinely performed with synthetic drugs, however, in the field of herbal drugs (HD), their preparations (HDP) and herbal medicinal products (HMP) this crucial property is generally not investigated. According to the European Pharmacopoeia, we have evaluated the dissolution behaviour of capsules containing various herbal drugs (Passira, Senna, Ginkgo) and some of their commercial dried extracts, manufactured with different methods, by analysis of their active components or marker constituents. Adequate dissolution behaviours of the flavonoids of Ginkgo were obtained for all preparations, while for both Passiflora and Senna only the extracts showed complete dissolution of the marker flavones and sennosides, respectively, in the investigated media.