Development of a nanostructured lipid carrier formulation for increasing photo-stability and water solubility of Phenylethyl Resorcinol

The Phenylethyl Resorcinol loaded nanostructured lipid carrier (PR-NLC) was developed by hot high-pressure homogenization method. The freshly prepared PR-NLC showed a spherical morphology under transmission electron microscope, and the particle size was 218.3 plus or minus 9.2nm. The value of the zeta potential of PR-NLC decreased from -30.2 plus or minus 1.9mV to -64.9 plus or minus 1.3mV when the dilution times reach 10. The loading amount of PR encapsulated in NLC was 2.94 plus or minus 0.03%, and the average entrapment efficiencies of PR-NLC determinated by size exclusion chromatography and ultrafiltration were 90.2 plus or minus 0.6% and 98.3 plus or minus 0.3%. Lyophilization was proved feasible for the storage of NLC dispersion. Fourier transform infrared spectra (FTIR) was exploited to investigate the possible drug-lipid complex formation. Advancements in water solubility of PR were demonstrated by NLC using a contact angle measurement. The hemolysis percentage of the NLC was less than 1.3% in a certain range of concentration. In 90 days' storage, 88.6 plus or minus 2.8% of PR remained unchanged in PR-NLC under natural daylight. In vitro release studies revealed a sustained drug release, and in vitro penetration studies showed an increase of retention amount of PR in the skin, when applying PR-NLC. Therefore, the NLC might be a potential delivery vehicle in cosmetic dermal products.