A promising and effective platform for delivering hydrophilic depigmenting agents in the treatment of cutaneous hyperpigmentation: kojic acid nanostructured lipid carrier

This study was aimed at preparing and characterising kojic acid nanostructured lipid carriers (KA-NLCs) for delivery to skin. KA-NLCs were prepared using high-speed homogenization followed by ultra-probe sonication method. KA-NLCs were optimized by glyceryl mono-stearate (GMS) and cholesterol (Chol) as solid lipid excipients, oleic acid (OA) as liquid lipid excipient, span 60 (SP 60) and Tween 20 (Tw 20) as co-emulsifiers. For optimized formulation (KA-NLC3), values of particle size, encapsulation efficiency, drug loading, polydispersity index (PDI) and zeta potential (ZP) were found to be 172.9 +/- 7.1 nm, 76.4 +/- 0.1%, 17.6 +/- 1.3%, 0.3 +/- 0.1 and -39.1 +/- 2.7 mV, respectively. KA-NLC3 was stable at 4 degrees C and 25 for 3 months. TEM image confirmed these results. ATR-FTIR, DSC and PXRD results indicated suitable entrapment of KA in NLCs without any chemical interaction. The release profile of KA-NLC3 followed a sustained pattern. KA-NLC3 has potent tyrosinase inhibitory activity in comparison with pure KA. Nanoparticles showed a higher antioxidant activity than pure KA. The results of the ex vivo and in vitro percutaneous absorption showed that KA-NLC3 improved percutaneous delivery of KA. Concentrations below 250 mu g/mL were determined as suitable concentrations for KA-NLC3. It seems to be biocompatible formulation for the cosmetics aims.

Automated summary

This study successfully prepared and characterised kojic acid nanostructured lipid carriers (KA-NLCs), with the optimized formulation KA-NLC3 showing stable drug release and enhanced percutaneous delivery for cosmetic applications.