BioXtra Dry Mouth Gel Mouthspray instantly relieves dry mouth. Bio Xtra Dry Mouth Gel Mouthspray - The minerals in the spray help to improve the mouths moisture, while the non-drying formula coats mouth surfaces, lips and throat. Natural salivary components help promote better oral health. Bio Xtra is convenient and easy to use during the day. To use Bio Xtra spray liberally onto gums, tongue and lips as often as required.