Determination of total hypericins in St. John's wort and herbal medicinal products

The work aimed to determine the levels of hypericins expressed as hypericin in the herbal substance of St. John's wort, in capsules and tablets containing the extract of St. John's wort, tablets containing powdered herb and in tincture and juice from fresh St. John's wort, by HPLC method with spectrophotometric detection. In addition, the amount of hypericins in the infusion prepared from St. John's wort was determined by HPLC and spectrophotometry methods. According to traditional indications aqueous infusions from St. John's wort containing mainly hydrophilic components are used in gastrointestinal diseases. On the other hand, ethanolic extracts containing hypericin and hyperforin affect the CNS and are indicated for the treatment of episodes of mild depressive disorders. The results obtained in the work indicate that the daily dose of hypericins taken by a patient as infusions is 0.328 mg on average for herbs in sachets and in bulk form. It can be compared to the daily dose of hypericins contained in tablets and capsules based on the alkoholic extract of St. John's wort and tablets containing powdered St. John's wort herb. For solid dosage forms, this dose ranges from 0.288 mg to 0.636 mg. The assays were performed using consistent analytical methods for all tested pharmaceutical products and consequently it was possible to compare doses taken by patients and their strength of action.