Safety of herbal medicines in the National List of Essential Medicines

Abstract

       Herbal medicines in the National List of Essential Medicines are medicines which the Ministry of Public Health encourages their use in government hospitals as an alternative to relieve symptoms or treat dieseases, as well as, to replace imported medicines. During fiscal year B.E. 2012-2013, Bureau of Drug and Narcotic, Department of Medical Sciences carried out a project on quality assurance of herbal medicines used in government hospitals by conducting safety studies consisting of tests for heavy metals and microbial contamination in herbal recipes, specified in the National List of Essential Medicines. Those recipes were herbal medicines in the following categories: antipyretic drugs, drugs used in symptomatic treatment of circulatory symptoms, respiratory system disorders, gastro-intestinal tract disorders, anti-diarrheal drugs, obestetrics and gynecological disorders and drugs used in musculo-skeletal symptoms. The recipes selected according to the mentioned categories were Ya-Khiewhom, Ya-Chanleela, Ya-Kaekaiharak, Yahom-Navakhoth, Yahom-Thepachit, Yahom-Bumronghuachai, Ya-Prasamawang, Ya-Thadbunchob, Ya-Leongpidsamut, Ya-Prasaplai and Ya-Sahastara. The testsfor heavy metals and microbial contamination were carried out using atomic absorption spectroscopy and Thai Herbal Pharmacopoeia’s method, respectively. The results, evaluated according to the Thai Herbal Pharmacopoeial standard criteria, showed that 3.8% of 156 samples, 4 recipes, including Ya-Khiewhom, Ya-Kaekaiharak, Yahom-Navakhoth and Ya-Prasamawanghad fand arsenic, lead and cadmium levels higher than the acceptable limits, where as, 25.9% of 116 samples, 7 recipes, including Ya-Chanleela, Ya-Kaekaiharak, Yahom-Navakhoth, Yahom-Bumronghuachai, Ya-Thadbunchob, Ya-Prasaplai and Ya-Sahastarawere found to be microbial contaminated. The recipes passed the acceptable limits on heavy metals and microbial contamination were Yahom-The pachitand Ya-Leongpidsamut.