Holographic Characterization of Biodegradable Poly Lactic-Co-Glycolic Acid (PLGA) Microbeads for Applications in Cosmetics

Microbeads are essential elements of many cosmetic products for opacifying, mattifying, determining the feel of the product, and enabling specific textures. Historically, microplastics have served these needs. More recently, concerns about the environmental impact of microplastics has led to the exploration of alternative materials for microbeads, with emphasis on biodegradability. In this work, Total Holographic Characterization (THC) is used to study Poly Lactic-co-Glycolic acid (PLGA) biodegradable microbeads in the size range of 500 nm - 5 μm. THC uses inline holograms to provide quantitative size, refractive index and concentration of colloidal particles. PLGA polymers are FDA approved biocompatible and biodegradable material for biomedical usage and a possible alternative to current polymer-based microbeads for cosmetic applications. THC provides quantitative measurement of PLGA colloidal particle size, refractive index and concentration under various environmental conditions. Our studies demonstrate the effectiveness of THC in differentiating PLGA microbeads from other types of microbeads. Different polymers can be distinguished by their refractive index. We analyze mixtures of PLGA in the presence of microbeads of other polymeric materials, to determine the concentration of multiple components in a heterogeneous mixture in a single measurement.