Folic acid-layered double hydroxides hybrids in skin formulations: Technological, photochemical and in vitro cytotoxicity on human keratinocytes and fibroblasts

• Published in: Applied clay science 2019-02, Vol.168, p.382-395
• Main Authors: Pagano, Cinzia, Perioli, Luana, Latterini, Loredana, Nocchetti, Morena, Ceccarini, Maria Rachele, Marani, Marco, Ramella, Daniele, Ricci, Maurizio
• Format: Article
• Language: English
• Subjects: Cytotoxicity; Fibroblasts; Folic acid; Keratinocytes; Layered double hydroxides; Photochemistry
• ISSN: 0169-1317; 1872-9053
• DOI: 10.1016/j.clay.2018.12.009

Folic acid (FA) is a key factor in the physiological processes of cell metabolism; as it is involved in DNA synthesis and repair, it can be used in the treatment of aged and photo-damaged skin. The main drawbacks associated to FA use, particularly for topical applications, are the limited solubility and the sensitivity to UV rays. Hybrids of FA with two kinds of layered double hydroxides (ZnAl-LDH and MgAl-LDH) were prepared and characterized showing suitable particle size, flow properties and UV photoprotection. The introduction of FA-LDHs in the external water phase of O/W emulgels produced an enhancement of their flow properties; moreover, the spectrophotometric analyses showed that very good photostability is maintained even after their introduction into the formulations. In-vitro release studies showed that the FA-LDH containing emulgels promoted a sustained FA release as expected. Finally, the safety of FA-LDH was evaluated by in-vitro studies performed on human keratinocytes (HaCaT) and human primary dermal fibroblasts (as a skin representative). The obtained results showed a high cytotoxic effect of ZnAl-LDH-FA in both cell lines. [Display omitted] •Hybrids of folic acid with hydrotalcite-like materials are photostable.•Hybrids are more easily dispersible in the formulation than crystalline folic acid.•The hybrids improve emulgel flow properties.•MgAl-LDH-FA is safe for keratinocytes and dermal fibroblasts.