Batch-to-batch reproducibility of St. John's Wort preparations

Over the last few years, St. John's Wort products have enjoyed a tremendous surge in interest and sales for the therapy of mild to moderate depression . Although the complete spectrum of active substances in this herbal extrac t has not yet been elucidated, it is certain that hyperforin is an importan t component (7,8]. Further, it appears that the hypericins may also contrib ute to the antidepressive activity [2]. In this study, the content uniformi ty of eleven St. John's Wort products sold exclusively in pharmacies was de termined. The main objective was to determine the batch-to-batch reproducib ility of the various products. The hyperforin was analysed according to a p reviously published HPLC method (4], while the total hypericin content was determined by an electrochemical method [6]. The results indicate that some , but not all, products show very reproducible batch-to-batch properties. A lso, individual products have different hypericin and hyperforin levels, an d are therefore not switchable even when products are manufactured under si milar extraction and processing conditions, have the same raw material: ext ract ratios (on a dry basis) and contain the same amount of extract per uni t dosage form.