Development of folic acid–loaded nanostructured lipid carriers for topical delivery: preparation, characterisation and ex vivo investigation

Abstract

The present work is designed to achieve efficient localised skin delivery of folic acid (FA)–loaded nanostructured lipid carriers (NLCs) to infer efficient treatment of skin photoageing conditions induced via excessive exposure to ultraviolet (UV) radiation. FA NLCs were prepared by high-speed homogenisation followed by ultrasonication. The obtained NLCs revealed high encapsulation efficiencies (89.42–99.26%) with nanometric particle sizes (27.06–85.36 nm) of monodisperse distribution (PDI = 0.137–0.442), zeta potential values >|27| mV, pseudoplastic rheological behaviour, good spreadability (2.25–3.30 cm) and promoted occlusive properties throughout 48 h. Optimised NLC formulations appeared as sphere-shaped particles using transmission electron microscopy, showed improved photostability of FA and prolonged in vitro release profile best fitted to Higuchi diffusion model. Ex vivo permeation and deposition of FA, employing Wistar rat skins, depicted enhanced permeability and existence of FA in skin layers after 6 h. Based on the obtained results, FA-loaded NLC formulations demonstrate a promising modality for anti-photoageing therapy.

Keywords:

• Folic acid
• nanostructured lipid carrier
• topical delivery
• spreadability
• occlusion
• skin permeation
• skin deposition

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

The authors appreciate funding the present work via the National Research Centre in-house project budget, number 10070109 as well as the PhD thesis budget provided by the National Research Centre, number 2/8/6.