Process Optimization for Preparation of an Antibacterial Agent Using a Combined Extract of Tulsi and Marigold Leaves

Medicinal plants and herbs contain substances known to modern and ancient civilizations for their healing properties. India is rich in biodiversity and many of its plants are known to have medicinal properties. This paper highlights two tropical and subtropical important plants -Ocimum sanctum (tulsi) and Targetes erecta (marigold) due to their easy availability and antimicrobial effectiveness. Several studies have been done on the antimicrobial properties of the individual extracts; however, few attempts have been made to study their antimicrobial properties in combination. The present work attempts to prepare an antimicrobial agent possessing the maximum efficiency, with a combination of leaf extracts from tulsi and marigold prepared in the most suitable solvent. Objective of the present work is to optimize the preparation method of the antimicrobial product and to check the properties of the product. Propylene glycol was found to be the most suitable extraction solvent. Process for preparation of the antimicrobial agent was then optimized by Response Surface Methodology using Design Expert Software 10. The extract retained its 72% and 62% of its antibacterial activity after 35 days when preserved at 4C against E.coli and S. aureus respectively.