Lack of quality standards of the raw material has been one of the major lacuna in the wider acceptance of plant based drugs. Medicinal Plants Unit of the Indian Council of Medical Research has initiated a programme for the preparation of quality standards for herbal raw materials involving several research institutes of the country to address this problem. This programme has resulted in publication of seven volumes on "Quality Standards of Indian Medicinal Plants" covering 239 plants.
The following major guidelines have been adopted in evolving the standards and preparation of the monographs.
The raw material of the plants is procured from the field, from at least three geographical locations and authenticated. The samples are worked out for their pharmacognostic and phytochemical features through experiments while the information on the distribution of the plants, vernacular names, chemical constituents, pharmacological activity, safety aspects, clinical studies if any, therapeutic claims and any other details are derived from the published literature and compiled in the form of a monograph, along with complete references of the work cited. The experiments conducted and the compiled data is subjected to careful scrutiny by the experts of the scientific committee. The information incorporated in the monographs is further supported by the photographs of the plant, the part/s of the plant used, microscopic details, the TLC details, chromatograms, etc.
The monographs are compiled and presented in a uniform format as described below:
Each monograph starts with the part(s) used, botanical name with authority, synonyms, habit and distribution of the plant.
Other Names: Include vernacular names of the drug (part of the plant that is being used) in different regions of the country.
Description: Contains macroscopy and microscopy of the drug with special emphasis on diagnostic characteristics, organoleptic examination of the raw material as well as its powder. Illustrated figures and photographs are also given.
Chemical Constituents: Are given with the structures of important compounds and active principles (if known). While making the structures of the chemical constituents, stereochemistry is also taken into consideration wherever information on stereochemistry of specific compounds is available. The chemical constituents are listed under two sub heads, viz., major and others. Under the former category, the chemical constituents which are either present in significant amount in the drug or are important from the activity point of view (active principle of the drug), even if present in relatively small amounts are given. Under the second category, the chemical constituents which are either present in small amount or their contribution towards the activity of the drug is not known, are listed.
Identity Tests: Chromatographic fingerprint profiles which have been generated using thin layer chromatography, high performance liquid chromatography or gas liquid chromatography, as per the suitability are given. TLC is found to be more practically feasible and suitable to resolve most of the components of the extract under study. As far as possible, fingerprint profiles are given along with a marker compound.
Assay/Analytical Methods: Are described in detail for the analysis of marker compound. In certain cases, chemical groups are estimated. In all the cases, sample preparation is optimized to enable complete extraction of compounds of interest.
Quantitative Standards: With respect to extractive values and ash values are derived by employing standard methodology and techniques as given in the Indian Pharmacopoeia or Ayurvedic Pharmacopoeia of India or WHO guidelines for Quality Standards of Medicinal Plants.
Adulterants/Substitutes: Are given wherever information is available and distinguishing features are cited with appropriate references.
Pharmacology: Includes important pharmacological activities of the part of the plant described as drug. The information is derived in majority of the cases from the original published articles in journals of repute. Clinical trials, wherever conducted have been mentioned.
Major Therapeutic Claims: Are derived from classical texts of Ayurveda with appropriate references and also other standard publications or evidenced by clinical trials reported in the literature.
Safety Aspects: Incorporates data available on the drug along with appropriate references. If no specific toxicity is reported, it is considered to be safe in the dose traditionally used.
Dose: Is taken from the classical Ayurvedic texts or from literature, if published.
The monograph is supported by colour photographs of the plant, the part of the plant used as drug, photomicrographs and/or camera lucida diagrams of the sections of the drug, and TLC fingerprint details and chromatograms, supported with complete references of the work cited.
In the initial pages of the book abbreviations used are listed, and the plants included in the first six volumes are also listed for ready reference. Towards the end of the volume, relevant appendices are included, carrying details of the methods for pharmacognostic evaluation of the raw material which includes macroscopic, microscopic studies and the quantitative standards (Appendix I), phytochemical evaluation (Appendix II), methods for the isolation of markers (Appendix III), methods of drying and storage of raw material (Appendix IV), limits of pesticide residues and microbial contamination (Appendix V) and plants allocated to various institutes for preparing the monographs (Appendix VI). The appendices section is followed by indices on the botanical names, chemical constituents and names of plants in other languages.
- Reviews on Indian Medicinal Plants (18 Volumes)