Standardization of milk thistle (Silybum marianum) syrup
Introduction. Milk thistle (Silybum marianum) fruits are a source of hepatoprotective drugs that are mainly tablets, capsules, and drag es. The liquid formulation (milk thistle syrup) is not currently prepared. Flavonolignans are a leading group of biologically active compounds of milk thistle fruits, which determines the hepatoprotective effect of drugs. Objective: to develop procedures for the qualitative and quantitative determination of active ingredients in holy thistle syrup. Material and methods. The syrup based on liquid milk thistle extract and sorbitol was a matter for this investigation. Sorbfil PTSH-AF-A-UV plates and a system of solvents, such as carbon tetrachloride-acetonitrile (6:4), were used for chromatographic analysis. A Specord 40 spectrophotometer (Analytik Jena) was employed to study UV spectra and to devise a procedure for quantitative determination. Results and discussion. A procedure for qualitative chromatographic analysis of the drug milk thistle syrup was proposed, which was based on the detection of flavonolignans. The chromatogram of the test solution showed a spot of silybin, a dominant flavonolignan, as well as silydianin, sily-cristin, and 2,3-dehydrosilybin. A procedure was developed to quantify in what amounts the milk thistle syrup contained flavonolignans calculated with reference to silybin by direct spectrophotometry (a detection wavelength of 289 nm). The amount of flavonolignans in the syrup ranged from 0.21±0.01 to 0.23±0.01%. Conclusion. Procedures have been developed for the qualitative analysis and quantitative determination of flavonolignans in the milk thistle syrup. The error of a single determination with a confidence level of 95% is ±3.57%.