pH adjuster for mouthwash

Hi guys,  I am formulating a natural herbal mouthwash and the preservative I am using is Gluconolactone & Sodium Benzoate Ecocert.. I was using citric acid as a pH adjuster because I need to get it down to 6 in order for the preservative to be effective, but it turns out there is a contraindication for using these together since it will oxidize the sodium benzoate converting it to Benzoic acid. I am looking for another way to lower my pH int his formulation. It will have to be food grade, any suggestions?  would acetic acid work??



  • BelassiBelassi Member, PCF student
    You have nothing to worry about. Acetic would be horrible.
    Cosmetic Brand Creation. Concept to name to IMPI search to logo and brand registration. In-house graphic design inc. Pantone specs. Cosmetic label and box design & graphics.
  • Bill_TogeBill_Toge Member, Professional Chemist
    phosphoric acid works well at very low levels, is readily soluble in water, is available in food grade, and is one of the least harmful acids as far as dental health is concerned; citric acid acts as a chelator and does a lot more damage to the teeth than non-chelating acids do

    also, if you're using sodium benzoate as a preservative, you'll have to get the pH below 5 for it to work
    UK based formulation chemist. Strongest subjects: hair styling, hair bleaches, hair dyes (oxidative and non-oxidative) I know some stuff about: EU regulations, emulsions (O/W and W/O), toothpaste, mouthwash, shampoos, other toiletries
  • Awesome thank you so much for the response. I am having trouble finding a supplier for  small amounts of phosphoric here in Calgary, Canada. would lactic acid work?
  • MarkBroussardMarkBroussard Member, Professional Chemist
    Try Phytic Acid (Dermofeel PA) from Dr. Straetmans.  It has some benefits for dental formulations.
    Chemist/Microbiologist formulating in the Organic & Naturals arena under ECOCert/Natural Products Assn/Whole Foods/National Organic Program guidelines focused skincare & haircare products. 

    See website for details
  • DuncanDuncan Member, Professional Chemist
    From past experience the choice of acid will depend upon the taste
    Citric acid - perfectly good, can get a bit Sour and Tart at high levels
    Phosphoric - not personally used that one for mouthwash, but you'll find it in products such as Coke or Pepsi
    Lactic: perfectly edible, but will probably taste like sour milk - which for oral care is not going to find favour with the end user 

    UK based, Over 20 years in Toiletries, After a 5 year sabbatical doing cleaning products, back in the land of Personal Care
Sign In or Register to comment.