Preparation of Dry Extract of<em> Mikania glomerata</em> Sprengel (Guaco) and Determination of Its Coumarin Levels by Spectrophotometry and HPLC-UV

• Main Authors: Maria da Penha Henriques do Amaral, Helena C. Castro, Rodrigo Luiz Fabri, Elita Scio, Camila de Sá Martins Muller, Leticia Oliveira Moreira Dias, Miriam Aparecida de Oliveira Pinto, Paulo César Stringheta, Larissa Brumano, Luciane Santos da Silva, Luciana Soares e Silva
• Format: Article
• Language: English
• Published: MDPI AG 2012-08-01
• Series: Molecules
• Subjects: pharmacotechnique; freeze-dryer; lyophilization; coumarins
• Online Access: http://www.mdpi.com/1420-3049/17/9/10344

Guaco (<em>Mikania glomerata </em>Sprengel) syrup is one of the most popular herbal medicines used to treat the symptoms of asthmatic bronchitis, cough and hoarseness. The coumarin 2<em>H</em>-1-benzopyran-2-one, is one of the major constituents of Guaco and contributes to its pharmacological effects. The pharmaceutical capsule form of dry extract of Guaco is recommended by the Brazilian Program of Medicinal Plants and Herbal Medicines and used in primary health care. In order to identify a new protocol to obtain the raw material for Guaco capsule production we evaluated two methods, including a freeze-drying process (lyophilization) and the spray-dryer technique, as well as the use of two adjuvants, Maltodextrins and Aerosil<sup>®</sup>, in different concentrations. The coumarin levels of the dried extracts were analyzed by UV-spectrophotometry and HPLC-UV/DAD. The adjuvant Aerosil<sup>®</sup> 8% showed better dry powder physical appearance. Lyophilization was observed to be the best process to obtain the dry extract of Guaco based on the measured coumarin levels.