T.A. Pozdnуakova - Senior Lecture, Medical Institute Orel State University. E-mail: pozdniakova95@mail.ru
R.A. Bubenchikov - Dr.Sc. (Pharm.), Kursk State Medical University. E-mail: fg.ksmu@mail.ru

Analysis of published data and our studies indicates the presence of a number of phenolic compounds, including tannins, in Geranium sibiricum L. Therefore, we attempted to standardize content of tannins in raw of Geranium sibiricum L. Development of sufficiently accurate and simple methods of quantitative determination of tannins, as well as its validation is an important issue. Therefore, the aim of our work was to conduct the validation methods of quantitative determination of the amount of tannins in the herb Geranium sibiricum L. The object of the study was Geranium sibiricum L., harvested in 2012-2013 in Orel and Kursk regions during the period of mass flowering. Herb was dried to air-dry condition and pulverized to a particle size of 1 mm. In the first phase studies were carried out on the development of quantitative methods of determining of the amount of tannins. A comparative evaluation of the content of tannins was made by three ways: permanganometric, complexometric and spectrophotometric, whereby it was found that the most efficient is the use of spectrophotometric method for the standardization of the Geranium sibiricum raw materials, as the most accurate and simple. During the study optimal extraction conditions were chosen: degree of crushing raw materials - 1 mm, the extractant was 50 % ethyl alcohol, the ratio of raw-ekstragent 1 : 100, heating for 45 minutes. Based on the studies proposed method for the quantitative determination of the amount of tannins, using as a standard sample of tannin. Validation of the methodology was carried out on the parameters of linearity, repeatability, reproducibility and accuracy of the methodology. The studies found that the methodology developed in this concentration range is linear, reproducible, obtainable, it takes a minimum of work, does not require expensive reagents. Analysis of five samples of herbs Geranium sibiricum showed, that total content of tannins in terms of tannin varies from 4.90 % to 7.08 %, which allowed us to propose standards for levels of tannins is not less than 4.0 %.

1. Nikitina V.S., Shendel' G.V. Soderzhanie fenol'ny'x soedinenij i aminokislot v nadzemnoj chasti Geranium pratense i Geranium sibiricum (Geraniaceae) // Rastitel'ny'e resursy'. 2008. T. 44. Vy'p. 2. S. 74-81.
2. Rastitel'ny'e resursy' Rossii: Dikorastushhie czvetkovy'e rasteniya, ix komponentny'j sostav i biologicheskaya aktivnost'. T.3. Semejstva Fabaceae - Apiaceae / otv. red. A.L. Budanczev. SPb.; M.: Tovarishhestvo nauchny'x izdanij KMK. 2010. S. 113-120.
3. Razarenova K.N., Zhoxova E.V. Sravnitel'naya oczenka soderzhaniya dubil'ny'x veshhestv v nekotory'x vidax roda Geranium L. flory' severo-zapada // Ximiya rastitel'nogo sy'r'ya. 2011. № 4. S. 187-192.
4. Gosudarstvennaya farmakopeya SSSR 11-e izd., dop. - Vy'p. 2. Obshhie metody' analiza. Lekarstvennoe rastitel'noe sy'r'e / MZ SSSR. M.: Mediczina. 1989. 400 s.
5. GOST 28508-90 E'kstrakty' dubil'ny'e rastitel'ny'e. Metody' opredeleniya. Moskva. Standartinform. 2006. 15 s.
6. Sklyarevskaya N.V. Farmakognosticheskoe izuchenie nadzemnoj chasti sabel'nika bolotnogo (Comarum palustre L.), proizrastayushhego na Severo-Zapade Rossii: Avtoref. dis. - kand. farm. nauk. SPb. 2009. 24 s.
7. GOST R ISO 5725-3-2002 «Tochnost' (pravil'nost' i preczizionnost') metodov i rezul'tatov izmerenij». Ch. 3 / Promezhutochny'e pokazateli preczizionnosti standartnogo metoda izmerenij. M.: Gosstandart. 28 s.
8. Meshkovskij A.P. Validacziya analiticheskix metodov / Sbornik «Sovremenny'e trebovaniya k organizaczii i deyatel'nosti kontrol'no-analiticheskix laboratorij otdelov kontrolya kachestva farmaczevticheskix predpriyatij». M. 2002. S. 26-30.
9. Osnovny'e princzipy' provedeniya validaczii na farmaczevticheskom proizvodstve / pod red. prof. V.V. Beregovy'x. M.: «Izdatel'skij dom «Russkij vrach». 2005. S. 73-97.