Abstract
INTRODUCTION.
The approved Russian regulations and guidelines on identification of medicinal products containing
Convallaria majalis
cardiac glycosides use group identification tests and thin-layer chromatography; spectrophotometry and bioassay are applied to quantify glycosides. Phasing out animal tests and lack of precision and reproducibility for bioassay methods necessitate the development of new physicochemical methods for the quality control of
Convallaria majalis
products.
AIM.
This study aimed to replace
in vivo
assay of cardiac glycosides in
Convallaria majalis
medicinal products with physicochemical analysis.
MATERIALS AND METHODS.
The study objects included Russian products:
Convallaria
tincture and Zelenin drops;
Convallaria majalis
extract reference standard, convallatoxin reference standard (93.0%). Biological activity was assessed on
Rana ridibunda
according to a compendial method. Convallatoxin content was determined using high-performance liquid chromatography (HPLC) within our method. Spearman’s rank correlation was assessed between the results of bioassay and HPLC/HPLC and spectrophotometry.
RESULTS.
The study proved validity of an HPLC method for identification and quantitation of medicinal products containing
Convallaria majalis
cardiac glycosides.
The content of convallatoxin, the predominant and most biologically active glycoside was determined by HPLC:
Convallaria majalis
extract standard reference — 0.14578 mg/mL;
Convallaria majalis
tincture — 0.01397 mg/mL; Zelenin drops — 0.00630 mg/mL; biological activity was determined as well. Spearman’s rank correlation of the findings was performed.
CONCLUSIONS.
An HPLC-based method providing precise and reproducible results has been proposed for convallatoxin identification and quantitation in
Convallaria
tincture and Zelenin drops. Recommended convallatoxin content:
Convallaria
tincture 0.01–0.02 mg/mL; Zelenin drops 0.004–0.008 mg/mL.