Determination of water absorption coefficients for some medicinal plant raw materials

Introduction. One of the key points in the manufacture of aqueous extracts (infusions and decoctions) is the volume of the extractant used for extraction. Since the dried medicinal plant raw material retains part of the water, it is necessary initially to take more water to obtain the required volume of water extraction, taking into account the water absorption coefficients. The values of the water absorption coefficients are given in the main regulatory document governing the manufacture of drugs in pharmacies - order of the Ministry of Health of the Russian Federation No.751n of 2015. However, in the order, the coefficients are given only for a limited range of medicinal plants. If there is no water absorption coefficient, the order gives recommendations to use the averaged values of the coefficients, which, of course, can lead to a mistakes in the volume and quality of water extracts. Objective: to establish the water absorption coefficients for some types of medicinal plant raw materials for their subsequent use in the manufacture of aqueous extracts in practical pharmacy, as well as in the educational process of educational institutions of the pharmaceutical profile. Material and methods. The objects of the study were Herba Poligoni avicularis, Herba Meliloti, Rhizomata et radices Inulae, Styli cum stigmatis Zeae maydis, Fructus Alni, Folia Betulae, Fructus Juniperi communis that meet the requirements of regulatory documents. Determination of water absorption coefficients was carried out in accordance with the methodology of General Pharmacopoeia Monograph 1.5.3.0012.15. Aqueous extracts were prepared in accordance with GPM.1.4.1.0018.15 “Infusions and decoctions”. Results. The water absorption coefficients were experimentally established for the Herba Poligoni avicularis, Herba Meliloti, Rhizomata et radices Inulae, Styli cum stigmatis Zeae maydis, Fructus Alni, Folia Betulae, Fructus Juniperi communis. It was proved that in the manufacture of water extracts, taking into account the established water absorption coefficients, the volume of the obtained water extraction fits into the norms of permissible deviations. Conclusion. For the studied medicinal plants, the water absorption coefficients were experimentally established, which allow to more correctly calculate the volume of the extractant when obtaining aqueous extracts.