The invention relates to a pharmaceutical composition for preventing and/or treating eye infections, which is to be used by local application. It is in particular directed towards such a composition which is in the form of an eye lotion which can be distributed by drops, in which an antibiotic of the macrolide class, such as azithromycin, is in solution in an oily vehicle. This vehicle is, in particular, of the type of product essentially consisting of medium-chain triglycerides in which the alcohol functions of the glycerol are entirely esterified by carboxylic acids made from saturated hydrocarbons, the molecule of which comprises from 5 to 12 carbon atoms. They are preferably linear-chain fatty acids comprising from 8 to 10 carbon atoms, such as caprylic acid or capric acid. The composition is advantageously prepared by dissolving the active agent in the oily vehicle at a temperature not exceeding 70.degree. C.