Hybrid Sunscreen for Albinistic Skin Types Augmented by Terminalia Sericea Mediated Silver Doped Zinc Oxide Nanoparticles, Efficacy and Safety Investigation

Albinism is a congenital hypopigmentation disorder characterized by errors in melanisation leading to the partial or complete absence of melanin, the skin’s primary defense against actinic damage. Actinic damage in albinism summarizes all solar induced consequences from freckles to fatal skin cancers. Of the 16 sunscreens approved by regulators, 14 chemical sunscreens were stripped of GRASE (Generally Recognizable as Safe and Effective) status in 2020 by the FDA though Over-the-Counter Monograph M020, the remaining 2 physical sunscreens (ZnO and TiO2) are unaesthetic, leaving unpleasant persistent white casts. The hunt for new, effective and safe sunscreen agents is on and photoprotective polyphenolics from tropical plants including Terminalia sericea, maybe the solution. This study aimed to develop and evaluate the efficacy and safety of a novel sunscreen for albinistic skin, utilizing Terminalia sericea-mediated silver-doped ZnO nanoparticles, so as to leverage the novel sun protection efficacy of aesthetic ZnO-NPs with the antibacterial effects of Ag-NPs as well as the photoprotective effects from T. Sericea polyphenolics. Our observations from the study confirm that T. Sericea possesses abundant polyphenolic compounds capable of mediating bio-reducing and capping of metallic nanoparticles. UV-Vis identified the nanostructures as Ag-ZnONPs, TEM confirmed their cubic and oblong agglomerated morphology. DLS estimated the nanostructures to be between 30 and 40nm. The sunscreen achieved a high SPF of 30, showed significant photoprotective properties, and demonstrated negligible skin sensitization in safety tests following OECD guidelines. It was therefore concluded that the biosynthesis of multifunctional Ag doped ZnONPs mediated by T. Sericea, was feasible and that the resultant safe multifunctional emulsion was efficacious in retarding biomarkers of actinic damage and is a potential pioneering albinistic skin type actinic damage retarding sunscreen.