Enhancing acne treatment with novel ternary metal complexes embedded in solid lipid nanoparticles: Development, in vitro characterization, and clinical evaluation

Objective(s): The aim of this study is to investigate the potential of Solid lipid nanoparticles (SLNs) to enhance the therapeutic effectiveness of ternary metal complexes of hydroxy acids in the treatment of acne.Materials and Methods: Ternary complexes of Cu (II) and Zn (II) with glycine amino acid (Gly) as a primary ligand, and Hydroxy acids (salicylic acid (L۱), lactic acid (L۲) or glycolic acid (L۳)) as a secondary ligand, were synthesized in a slightly acidic medium and isolated in different ratios. These ternary complexes were loaded into SLNs and evaluated for particle size, polydispersity index, Zeta potential, entrapment efficiency and in vitro release studies. SLN-encapsulated ternary metal complexes were clinically evaluated in acne patients.Results: Scanning Electron Microscopy revealed that SLNs were spherical in shape and varied in size from ۱۱۵ to ۲۱۰ nm when measured with a Malvern Zetasizer. The zeta potential was ranged from -۴۱.۳۳ ± -۲.۵ to -۴۷.۳۲ ± -۲.۱ mV. The calculated entrapment efficiency (EE%) was ۷۹ - ۸۳% with slow release of the ternary complexes from the prepared SLNs. The in-vivo clinical study disclosed that Zn(L۱)(Gly) SLNs outperformed Cu(L۱)(Gly) SLNs in terms of acne spot reduction and patient satisfaction.Conclusion: In conclusion, this study demonstrated that SLNs-encapsulated ternary metal complexes are a promising new treatment for acne.