Another Reason for Using Caffeine in Dermocosmetics: Sunscreen Adjuvant.

Area of Science:

• Dermatology
• Cosmetic Science
• Photoprotection

Background:

• Excessive ultraviolet (UV) radiation exposure is a primary cause of skin cancer.
• There is a need for advanced sunscreens with bioactive compounds like caffeine, known for antioxidant and anticancer properties.

Purpose of the Study:

• To evaluate the efficacy and safety of topical sunscreen formulations with caffeine as a UV filter adjuvant.
• To assess the impact of caffeine on skin hydration, barrier function, and colorimetry.
• To determine the Sun Protection Factor (SPF) of caffeine-containing sunscreens both in vitro and in vivo.

Main Methods:

• Formulations with and without 2.5% w/w caffeine were prepared.
• In vivo safety assessments included stratum corneum hydration, skin barrier function, and colorimetry.
• In vitro efficacy was measured using PMMA plates and spectrophotometry; in vivo efficacy was determined by SPF measurements.

Main Results:

• No tested formulations caused erythema or impaired skin barrier function.
• Caffeine-containing sunscreens demonstrated higher SPF values in vitro.
• In vivo studies confirmed increased SPF and approximately 25% greater anti-UVB protection with caffeine.

Conclusions:

• Caffeine is well-tolerated on the skin.
• Caffeine acts as an effective adjuvant, enhancing the photoprotective activity of sunscreens.
• Caffeine presents a novel alternative for sunscreen formulations to improve UV protection.