High-purity medium-chain monoglycerides composed only of plant-derived raw materials have a wide-ranging antibacterial spectrum against bacteria and fungi. These anti-bacterial ingredients are suited for food additives, very safe, have an emollient effect, and do not irritate the skin. These high-purity medium-chain monoglycerides make preservative-free prescriptions possible, and are also likely to reduce the amount of preservatives added. Additionally, we suggest anti-bacterial formulations based on this ingredient as an ingredient that can easily be mixed into a water-based prescription such as lotion.