Qualification of Sunscreens Using Certified Reference Materials

Nick Hauser, Product Manager Reference Materials

Absorbing the sun’s rays helps the body create an important nutrient, Vitamin D, for immune system function and proper bone density. Exposing oneself to sunlight can have positive effects - setting the body’s internal clock and thus affecting sleep cycles and emotional well-being. In some cases, however, too much exposure to sunlight can be harmful. The ultraviolet (UV) radiation that the skin is exposed to while soaking in the sun’s rays may lead to skin damage. Sunburn may be an immediate result of exposure to UV radiation, while over time, there is even the potential for developing skin cancer. Worldwide, nearly three million new diagnoses of skin cancer are observed every year.

UV radiation from the sun that reaches the earth is composed of two types of light, ultraviolet A (UVA) and ultraviolet B (UVB). Both UVA and UVB rays can cause cancer; however, roughly 95% of the sun’s rays are made up of UVA rays. UVA rays are considered to be long wave light and play a major part in skin aging and wrinkling. Even though UVB rays are much less prominent, they are potentially more harmful in the short-term as they are often identified as the cause of sunburns.

One way that people help protect themselves from the harmful effects of the sun is through the use of sunscreens. The use of sunscreen can help to prevent skin from aging and wrinkling as well as prevent sunburns. The risk of skin cancer can also be decreased with the use of sunscreens.

Sunscreens are widely available in various types and forms such as lotions, gels, sprays, and creams. Many of the active ingredients found in sunscreen will absorb the UV radiation from the sun, thereby protecting the skin. These are typically organic compounds and can include several different individual compounds which may specifically target the absorption of UVA or UVB rays depending on their structure. Several other inactive compounds to comprise the remaining portion of the formulation. These inactive compounds will vary depending on the specific form of the sunscreen itself and can include preservatives and excipients.

Due to the inherent absorption of sunscreens directly into a person’s skin, several regulatory bodies across the world, such as the U.S. Food and Drug Administration, regulate sunscreen products as over- the-counter drugs. Manufacturers of sunscreens are required to provide information regarding the safety of the ingredients that are included in their particular formulation. The use of Reference Materials is imperative to prove the quality and safety of those ingredients.

Supelco® Certified Reference Materials (CRMs) are available for several ingredients found in sunscreens as listed below. These CRMs are Secondary Pharmaceutical Reference Standards and are traceable to and qualified against the corresponding pharmacopoeia primary standards, eliminating the time and effort involved with preparing and validating in-house working standards.

A comprehensive Certificate of Analysis offers details of the methodology and results of the characterization. For more information on sunscreen related CRMs, or to view a complete product listing of our pharmaceutical secondary standards, please visit our website for Pharmaceutical Secondary Standards.

Materials

Description UV absorbent Preservative Excipient Pack size Cat. no.
Avobenzone x         1 g PHR1073
Ensulizole x         1 g PHR1301
Homosalate x         1 g PHR1085
Octinoxate x         1 g PHR1080
Octisalate x         1 g PHR1081
Octocrylene x         1 g PHR1083
Oxybenzone x         1 g PHR1074
Padimate O x       10 g PHR1355
Butylparaben   x       1 g PHR1022
Ethylparaben   x       1 g PHR1011
Methylparaben   x       1 g PHR1012
Propylparaben   x       1 g PHR1010
Cetyl Alcohol     x     1 g PHR1133
D4 Cyclomethicone     x 500 mg PHR1565
D5 Cyclomethicone     x 500 mg PHR1566
Dibutyl Phthalate     x     1 g PHR1366
Diethyl Phthalate     x     1 g PHR1476
Disodium EDTA     x     1 g PHR1068
DMDM Hydantoin     x     1 mL PHR1358
Phenoxyethanol     x     1.5 g PHR1121
Propylene Glycol     x     1.5 g PHR1051
Retinyl Palmitate     x     1 g PHR1235
Sodium Lauryl Sulfate     x     2 g PHR1949
Tocopheryl Acetate     x 500 mg PHR1030