It is the main medicine and the medium chain fatty acid mono glyceride and the impregnant for the mastitis which contains the oily base, spread detachability of the main medicine improves by the medium chain fatty acid mono glyceride, can raise the liquation characteristic of the main medicine and can raise absorptivity, compares in the impregnant for the former mastitis and possesses same effective characteristic and residual period is short, furthermore, can expect the effective application which is not wasteful of the main medicine.主剤と、中鎖脂肪酸モノグリセライドと、油性基剤を含有した乳房炎用注入剤であり、中鎖脂肪酸モノグリセライドによって主剤の拡散・分散性が向上され、主剤の溶出性が高められて吸収性が高められ、従来の乳房炎用注入剤に比して即効性を有し残留期間が短く、更に、主剤の無駄のない有効な活用が期待できる。