What does W/W mean on the MI Paste PLUS packaging?
w/w is an abbreviation for “by weight,” used in chemistry and pharmacology to describe the concentration of a substance in a mixture or solution. Properly speaking, 2% w/w means that the mass of the substance is 2% of the total mass of the solution or mixture. The metric symbol g/g has the same meaning as w/w. W/W stands for weight per weight. When we prepared a tube for Tooth Mousse PLUS prior to the launch in Australia, we checked the labelling of fluoride contained toothpaste available from Colgate. They stated like “Active ingredients: Sodium Fluoride 0.22% W/W”. We also checked the OTC drug labelling guideline by FDA and found that they recommended to put both of percentage and ppm on the package, as ppm might be confusing for the end-users. Therefore we finally decided to put the amount both in ppm and percentage.
