Scientific-methodological approach for standardization of herbal raw materials and herbal preparations using high-performance thin-layer chromatography procedure

The high-performance thin-layer chromatography (HPTLC) is widely used for quality control of herbal raw materials (HRM). The purpose of this work were to define the problematic issues of quality control of herbal drugs in Ukraine and to develop a systematic scientific and methodological approach for the standardization of HRM and herbal drugs using the modern analytical technique of HPTLC: to optimize the existing and develop new methods of identification and determination of adulterations, and to develop alternative methods of quantitative determination, as well as studying of the stability. As a result of a critical evaluation of existing approaches for the standardization of HRM and herbal drugs of Ukraine’s flora, numerous problematic issues were identified, including the existence of a limited number of national monographs / national parts of monographs on the HRM of the Ukraine’s flora, which were not previously standardized by other pharmacopeias; non-consideration of Ukraine’s flora species (non-pharmacopoeial) in monographs on closely related species that introduced in the State Pharmacopoeia of Ukraine; lack of specificity of combinations of physical and chemical methods used for quality control; lack of specificity and reproducibility, the labor intensity of methods; necessity of usage of toxic solvents and precursors; use of different groups of markers and methods for the HRM and its finished product or HRM and its closely related species, etc. The proposed systematic scientific and methodological approach includes: a preliminary collection of information about the object of study, markers/groups of bioactive substances, approaches to its standardization; theoretical evaluation of existing techniques of quality control in monographs on HRM and experimental approbation using samples of domestic plants, determination of the need for optimization of existed methods by the parallel development of specific, reproducible and documented methods for identification, adulterations’ detection, quantification, and bio-detection (if necessary) by HPTLC method. The approach is illustrated with examples. The proposed approach can be used for comprehensive HPTLC analysis of domestic HRM and herbal drugs for research, prevention of adulteration, standardization of initial HRM and its finished product, pharmaceutical development, and stability studies.