Novel synthetic dermal fillers based on sodium carboxymethylcellulose: comparison with crosslinked hyaluronic acid-based dermal fillers.

BACKGROUND: The persistence of dermal fillers containing crosslinked hyaluronic acid (XLHA) correlates linearly to the concentration of polymer in solution. For dermal fillers composed of XLHA, a polymer concentration above approximately 25 mg/mL is not practical because it cannot be easily injected through a small-bore needle.
OBJECTIVE: Formulating dermal fillers from mixtures of carboxymethylcellulose (CMC) and polyethylene oxide (PEO) has several advantages over XLHA. We hypothesize that increasing the concentration of CMC/PEO will increase the persistence in the dermis. These polymers of CMC and PEO can be formulated at higher concentrations than XLHA to produce smooth, particulate-free gels resulting in easier, more controllable injection. Second, these gels are not required to be covalently crosslinked; CMC/PEO forms a stable gel-like structure in solution without crosslinking.
MATERIALS AND METHODS: Here we have prepared dermal fillers from CMC/PEO polymer blends at concentrations of 20 mg/mL (dermal filler 1), 29 mg/mL (dermal filler 2), 37 mg/mL (dermal filler 3), and 45 mg/mL (dermal filler 4) and measured their rheologic properties compared to commercial XLHA dermal fillers. RESULTS AND
CONCLUSIONS: The data here demonstrate that it is possible to duplicate the rheologic properties of commercial XLHA fillers using CMC/PEO at different polymer concentrations to formulate improved dermal fillers. All of the dermal filler formulations prepared can be easily injected through 30-gauge needles.