Comparative study of rheological properties and preclinical data of porous polycaprolactone microsphere dermal fillers

Abstract Background In this study, a physical properties test and preclinical evaluation were performed on two polycaprolactone (PCL)‐based dermal filler formulas. Objective This study was performed to compare the rheological characteristics, preclinical efficacy, and safety of a new PCL filler, SF‐01, with a licensed PCL filler. Methods First, the viscoelasticity of the PCL filler was evaluated. Next, hairless mice were injected with fillers and evaluated for efficacy with a folliscope and PRIMOS LITE . Histological evaluation was conducted for 6 months to evaluate safety. Results In this evaluation, SF‐01 was superior to a licensed PCL filler in initial volume increase rate and in vivo durability, and the migration of the injected filler was not confirmed. The elasticity (G*, G′) and viscosity (G′′) are also expected to be lower than those of a licensed PCL filler, thereby resulting in less foreign body sensation in the living body. Conclusion SF‐01 (porous PCL microsphere–based dermal filler) has been confirmed to be superior in durability and shape retention compared to the licensed PCL filler (nonporous PCL microsphere–based dermal filler), and the in vivo safety is equivalent.