Enhancement of Skin Permeation and Penetration of β-Arbutin Fabricated in Chitosan Nanoparticles as the Delivery System

Abstract

Background: There has been an increase in demand for cosmetic skin-whitening products with efficacy toward lightening skin tone. β-arbutin is an inhibitor of tyrosinase enzyme activity within the skin’s melanocytes, and so has shown considerable promise as a skin-lightening agent. It is, however, both hydrophilic and hygroscopic, which hinders its penetration of the skin to reach these melanocytes. Chitosan (CS) possesses considerable penetration-enhancing properties when utilized in topical delivery formulations. The strong affinity of positively charged chitosan nanoparticles toward negatively charged biological membranes can be exploited to achieve site-specific targeting. Objective: To investigate the use of chitosan nanoparticles (CSNPs) as carrier units to enhance the topical delivery of β-arbutin. Method: CSNPs containing β-arbutin were prepared using an ionic cross-linking method, and entrapment efficiency and loading capacity were evaluated at numerous β-arbutin concentrations. Further characterization involved using FTIR, XRD, TEM, and TGA, and in vitro permeation studies were conducted using in vitro Franz diffusion cells. Results: β-arbutin chitosan nanoparticles were successfully formulated with a size range of 211–289 d.nm, a polydispersity index between 0.2–0.3, and zeta potential in the range 46.9–64.0 mV. The optimum encapsulation efficiency (EE) and loading capacity (LC) of β-arbutin were 68% and 73%, respectively. TEM revealed the nanoparticles to be spherical in shape. FTIR spectra revealed characteristic chitosan-related peaks appearing at 3438.3 cm−1 (-OH stretching) and 3320 cm−1 (-CH stretching), together with 1598.01 cm−1 (-NH2) specific to β-arbutin nanoparticles. XRD analysis revealed an increase in crystallinity and TGA analyses identified increasing thermal stability with increasing β-arbutin concentration. In vitro studies indicated higher permeation and improved penetration of β-arbutin loaded in CSNPs compared to its free form. Conclusion: CSNPs present considerable promise as effective carriers for improved topical delivery of β-arbutin.