There is lot of adulteration and substitution of herbal raw materials, especially in case of bark drugs. Different plant materials are being sold in the market under the same vernacular, for example 'Asoka' - Saraca Asoca is the genuine plant species but bark of other plant taxa are being mixed up and sold or used under the name 'Asoka'. It is also apparent that after drying, it is very difficult to differentiate the bark of the same genus, as in case of 'Siris', instead of Albizia lebbek, barks of other Albizia species are being sold. Similarly, the bark of 'Arjuna' is also substituted with other Terminalia species. Therefore, in the present publication, attempt has been made to lay down quality parameters of 40 barks and their possible adulterants/substitutes.
This book is intended to present elements of both methods and indispensable techniques used for quality control and standardization of bark drugs. More emphasis has been made on classical pharmacognostical and phytochemical approaches in order to determine the correct botanical identity of the genuine source of the plant material required to be used in number of herbal formulations. Parameters selected are: botanical name with authority; family; synonyms, vernacular names; botanical description; distribution; macro and microscopic description with special emphasis on diagnostic characters supported by photographs; powder microscopy with camera lucida drawings. Apart from this, thin layer chromatographic profile has been developed and depicted by photographs of TLC plates and densitometeric scans of the chromatograms with a view to establish the diagnostic chemical profile of different bark drugs. In addition, all the stem barks were also screened for some terpenoids and polyphenols, as marker components, which are generally present in the bark drugs. The information presented in this book will have a considerable impact on the standardization and quality control of bark drugs and to check their possible adulterants and substitutes. Hence, it serves as a ready reckoner for pharmaceutical industries and academics particularly the researchers, teachers and students engaged in herbal drug research or study of indigenous systems of medicine.