Background: The physical and chemical properties that control the clinical persistence of temporary dermal fillers are not well understood. Discovering the relationship between the clinical performance and physical properties of temporary fillers may stimulate the design of future, high-performance fillers.
Objective: Described here is the rheology of polysaccharide dermal fillers composed of cross-linked hyaluronic acid (XLHA) or un-cross-linked sodium carboxymethylcellulose (CMC) and polyethylene oxide (PEO). Using measured rheology data and published clinical study data, we have developed a predictive model for the persistence of polysaccharide-containing dermal fillers.
Methods and materials: The XLHA dermal fillers were obtained from commercial sources. The CMC/PEO dermal filler formulation was prepared in house. The rheologic properties of the polysaccharide fillers were measured and related to comparative clinical persistence data available from controlled clinical studies.
Results: The clinical persistence of the polysaccharide dermal fillers correlates linearly with the concentration of polymer in the formulation divided by the tan delta (G''/G').
Summary: The work described here has shown that a model relating the concentration of the polysaccharide and the tan delta of the formulation can predict the comparative clinical persistence of XLHA and CMC/PEO dermal fillers.