Development of solid lipid nanoparticles containing Artocarpus Lakoocha heartwood extract (puag-haad) for whitening and anti-wrinkle effects

Abstract

The main purpose of this study was to develop solid lipid nanoparticles (SLN), an alternative carrier system, for Artocarpus lakoocha heartwood extract (Puag-Haad) to improve Puag-Haad stability and evaluate the whitening and anti-wrinkle efficacies in woman volunteers. At optimum formulations, SLN containing Puag-Haad were successfully developed by w/o/w double emulsion and cold homogenization method using glyceryl monostearate, polyoxyethylene 40 stearate and poloxamer 188 as lipid, surfactant and cosurfactant, respectively. The mean particle sizes and zeta potentials of formulations, when measured by photon correlation spectroscopy (PCS), were 150 – 190 nm for w/o/w double emulsion method and were 250 – 320 nm for cold homogenization method. The particles showed regular, spherical and uniform nanospheres when investigated by transmission electron microscope (TEM). Purification of SLN containing Puag-Haad was achieved by ultrafiltration. Analysis of the amount of oxyresveratrol, a main constituent in Puag-Haad, by high performance liquid chromatography (HPLC) showed high entrapment efficiency of about 85% for w/o/w double emulsion method and 70% for cold homogenization method. In vitro release studies showed sustained release profiles of oxyresveratrol and well fitted the Higuchi equation. After 4 months storage at room temperature and protected from light, the physical and chemical stabilities of SLN containing Puag-Haad (0.25%) were superior to the aqueous solutions of Puag-Haad. The presence of surfactant (polyoxyethylene 40 stearate) and citrate buffer pH 5.5 had additive effect in stabilizing Puag-Haad both physically and chemically. Twenty-six woman volunteers participated in an 8-week study. Each applied the SLN containing Puag-Haad (0.25%) on one of the forearm in comparison with the micellar solution of Puag-Haad on another forearm. The melanin index, skin roughness, skin elasticity and skin hydration were measured every 2 weeks. Repeated measures ANOVA was employed to evaluate the difference in the overall effect between the two formulations over time at the significance level () of 5%. SLN containing Puag-Haad gave significantly better anti-wrinkle, skin elasticity and skin hydration than the micellar solution. On the other hand, the solution showed slightly greater whitening effect than SLN. All the subjects completed the study without developing any unwanted side effects or withdrawal. Therefore, the SLN containing Puag-Haad appeared to have a very promising potential as a novel and effective skin whitening / anti-wrinkle cosmetic delivery system.