Further sunscreen studies of aminobenzoic acid

Shedding light on sunscreens

“…Para‐aminobenzoic acid (PABA) and its derivatives form a further category of popular UVB filter, especially in the USA and Scandinavia; 15 PABA is very efficient at a 5% concentration in a 50–60% alcohol base, 16 –20 any increase in the alcohol or water content decreases its protective value 21 . The main advantage of this agent is its ability to penetrate the horny layer of the skin, which takes at least 30 min, after which it is not easily removed by swimming, washing or perspiration; 17 such a reservoir effect could also be due to PABA crystals within the surface of the skin; 22 although, the protection does decrease after swimming 23 .…”

Properties of Topical Sunscreen Formulations: A Review

“…However, this process does not take place immediately after application of the sunscreen, but develops within an hour following application 20 . Hydration of the skin prior to the application of PABA has also been shown to increase absorption of the sunscreen 27 …”