A double-blind investigation of the potential systemic absorption of isotretinoin, when combined with chemical sunscreens, following topical application to patients with widespread acne of the face and trunk.

Author(s): Cunliffe WJ, Glass D, Goode K, Stables GI, Boorman GC

Affiliation(s): Department of Dermatology, The General Infirmary at Leeds, UK.

Publication date & source: 2001-01, Acta Derm Venereol., 81(1):14-7.

Publication type: Clinical Trial; Randomized Controlled Trial

This study assessed the systemic absorption of isotretinoin and its metabolites, during a 4-week application of a cream containing 0.1% isotretinoin and chemical sunscreens, compared with a 4% benzoyl peroxide cream, in patients with acne on the face and trunk. Blood was drawn at weeks 0, 1, 2, 3 and 4 and at 96 h post-treatment. Plasma levels of isotretinoin (13-cis-retinoic acid) and tretinoin (all-trans-retinoic acid) were quantified by liquid chromatography with tandem mass spectrometry and the presence of their combined 4-oxo metabolites were monitored from the peak area ratios observed. The isotretinoin group showed no statistically or clinically significant increases in plasma retinoid levels and mean levels did not exceed +/-2 SD of the mean pre-treatment values, indicating that endogenous levels were not being exceeded. No significant differences were detected between the isotretinoin group and the 4% benzoyl peroxide group. These findings indicated that retinoid absorption from a cream containing 0.1% isotretinoin and chemical sunscreens was clinically insignificant, when applied to patients with widespread acne.