All perfect praise be to Allaah, the Lord of the worlds. I testify that there is none worthy of worship except Allaah and that Muhammad, sallallaahu ‘alayhi wa sallam, is His slave and messenger.
There is nothing wrong with the fasting person using nebulizers during the daytime in Ramadan if this device does not cause something to reach the person’s throat. If it causes something to reach the throat, then it is not permissible for the fasting person to use it during the daytime in Ramadan unless one must do so, in which case a person can use it and make up for that day later.
Allaah Knows best.