Retinaldehyde (RA), vitamin A derivative, is an intermediate between retinol and retinoic acid and has an excellent wrinkle improving effect. In this study, Drug-in-cyclodextrin-in-liposome (DCL) was used to enhance the stability and skin penetration of RA. The complex of RA and hydroxypropyl-beta-cyclodextrin (HP-?-CD) was prepared by the freeze-drying method, and the presence or absence of inclusion of retinal was confirmed by UV-vis spectrometer, FT-IR and SEM images. RA was captured in HP-?-CD about 95.6% on 1:15 (w/w). The retinal-HP-?-CD complex was encapsulated in liposomes using a homomixer and microfluidizer, with an average particle size of 215 ± 4.2 nm and a zeta potential of -31.2 ± 0.5 mv. In the evaluation of the degradation stability of RA, degradation rate of RA-HP-?-CD-liposomes in water was 1.8% higher than RA-liposome (5.8%), RA-HP-?-CD complex (9.7%) and RA alone (37.6%). RA cream (0.05% RA) including RA-HP-?-CD-liposomes was prepared for clinical test with wrinkle-improving efficacy and skin dermis denseness evaluated for 2 or 4 weeks. RA cream showed a significant wrinkle improving effect without skin irritation. In conclusion, double stabilization technology using the DCL system enhances the stability and skin penetration rate of retinal and contributes to the effect of improving skin wrinkles. 

Ji Hoon Ha has completed his PhD at the age of 32 years from Seoul National University of Science and Technology, South Korea. He is the researcher manager of Convergence Research Institute of Korea Kolmar, South Korea. He has over 38 publications that have been cited over 220 times.