TESTING PHARMACEUTICAL RELEASE OF ACTIVE SUBSTANCES FROM MEDICINAL PRODUCTS CONTAINING ST. JOHN'S WORT

The aim of this study was to determine the content of hypericins and flavonoids in tablets and capsules containing the extract or powdered herb of St. John's wort, in herbs for infusion and herbal infusions and to release of these compounds from tablets and capsules. HPLC method was used to determine the assay of hypericins and flavonoids in all tested products. The hypericins content was between 0.35 mg and 1.44 mg per tablet or capsule. The release of hypericins from these products in the phosphate buffer of pH 6.8 is between 30 and 60% of the determined content. The degree of hypericins release from herbs into infusions was 15% on average, which corresponds to 0.64 mg of hypericins per infusion of 4 g of herbs. The flavonoids content was between 8.79 and 36.3 mg per tablet or capsule. The release of flavonoids in the phosphate buffer of pH 6.8 is between 63 and 85% of the determined content. The degree of flavonoids release was 76% on average, which corresponds to 77.0 mg per infusion of 4 g of herbs. The test results confirmed that infusions from the St. John's wort constitute are a rich source of flavonoids. At the same time, the universally accepted opinion that aqueous infusions contain only trace amounts of hypericins was not confirmed. Infusions from Herba hyperici may also be a source of hypericins in amounts comparable with the minimum dose recommended for the treatment of mild to moderate depressive episodes.