Photostabilization strategies of photosensitive drugs

Several active compounds are sensitive to light, especially to the ultraviolet radiation (UV-R) leading to their degradation or modification, with lost or decrease of their biological activity. The aim of this study was to perform a systematic review regarding photostabilization strategies used on health products and perform a critical appraisal of their effectiveness.The bibliographic search identified 2261 results and merely 40 studies met the selection criteria. Of these, 85% referred to encapsulation strategies, 10% to antioxidants and 5% to the use of solar filters. Cyclodextrins (CD's) were the most used encapsulation systems (32.5%) followed by liposomes and lipid nanoparticles (each 17.5%), microparticles (15%) and polymeric nanoparticles (10%). The most effective were found to be liposomes and lipid nanoparticles. However, the different methodological conditions used limit the true relevance of this finding.A gold standard strategy suitable for all compounds cannot be proposed. Instead, case-by-case evaluation, supported on the photodegradation mechanism is recommended. Systematic studies that compare different photostabilization strategies undertaken with the same irradiation conditions are also needed.