Development and validation of spectrophotometric procedure for quantitative determination of flavonoid content used to control the quality of mixture herbal product.

Species, known as mixture herbal products, are compositions of several types of crushed, sometimes whole, medicinal plant materials with additives; they are a widely used dosage form in the Russian Federation. A large range of species are produced at the pharmaceutical companies. In pharmacopoeial analysis, the most popular and widely used method for the determination of flavonoids, suitable for the standardization of species, is the method of differential spectrophotometry, based on the complexation of flavonoids with aluminum chloride.