This invention relates to a dual phase mouthwash comprising a hydrophilic phase, a hydrophobic phase, and a hydrotrope, wherein the hydrophilic phase comprises an effective amount of a preservative selected from methylisothiazolinone, sodium benzoate, potassium sorbate, and combinations thereof, as well as to methods of using and of making such compositions.本發明係關於一種含有親水相、疏水相和增溶劑的雙相潄口液,其中該親水相含有選自甲基異噻唑啉酮(MIT)、苯甲酸鈉、山梨酸鉀及其組合之一有效量防腐劑,以及係關於利用和製造此類組成物的方法。