Formulating Water-resistant Sunscreen Emulsions

The sunscreen market has been ever-changing and has become more segmented since the publication of the proposed sunscreen monograph more than 20 years ago. To thos of us who formulated sunscreen products in the good old days (actually I didn't get into the sunscreen business until 1983), it was indeed a simpler time. The maximum SPF (Sun Protection Factor) ever targeted was 15, and most products were not required to be waterproof. Note that today we aren't permitted to use the term "waterproof" since the FDA believes that this term implies an absolute-it never washes off-and feels that consumers might be inclined not to reapply sunscreen after swimming or perspiring. So, we must now use the term "very water resistant" in its place.