Helioplex, Tinosorb, UVA radiation

February 1, 2006

At present, there are no plans to gain approval for the use of Tinosorb in the United States. It is both expensive and laborious to gain approval.

Q. What is Helioplex?

The product was first introduced in November 2005 in Neutrogena's SPF 55 Ultra Sheer sunscreen and will eventually be added to the company's sunscreen-containing moisturizers. Helioplex is a proprietary combination of avobenzone (also known as Parsol 1789), oxybenzone and a photostabilizing solvent, Hallbrite TQ. Avobenzone is an excellent UVA photoprotectant, but it is photounstable. After about five hours of UVA exposure, which equates to about 50 joules of energy, avobenzone imparts little photoprotective qualities to the sunscreen. One way of stabilizing avobenzone is by adding mexoryl, however mexoryl has not been approved for use in the United States. The photoinstability of avobenzone led Neutrogena to look for other approaches to stabilize avobenzone within options approved by the Food and Drug Administration (FDA).

Q. What is Tinosorb?

A. Tinosorb is another new sunscreen ingredient that is widely used in China, but not approved in the United States.

Tinosorb was developed by the fabric dye division of Ciba Specialty Products in High Point, N.C., a city that I call home. It is actually a white, powdered pigment that has photoprotective capabilities. It is similar to zinc oxide in that it mainly reflects UV radiation with some minimal absorption; however, it provides better photoprotection than titanium dioxide. At present, there are no plans to gain approval for the use of Tinosorb in the United States. It is both expensive and laborious to gain approval for a new sunscreen additive, and the financial rewards for new sunscreen development are not nearly as great as for new cholesterol-lowering medications. This is, indeed, unfortunate, but it is reality as it now stands with the regulatory bodies in the United States.

Q. Is UVA radiation consistent throughout the year?

A. I had been taught as a dermatology resident that UVB radiation varied seasonally, but UVA radiation remained consistent throughout the year in a given geographic location. This is a fact that I had frequently quoted in my sunscreen lectures. I was surprised to learn from the photobiologists at Neutrogena that UVA radiation decreases in December. However, I realize that the lower December UVA radiation can be easily overcome with tanning booth exposure in any part of the country.

Zoe Diana Draelos, M.D., is a clinical associate professor of dermatology, Wake Forest University School of Medicine, Winston-Salem, N.C., and primary investigator, Dermatology Consulting Services, High Point, N.C. Questions may be submitted via e-mail to zdraelos@northstate.net
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