Rheological Properties of Calcium Hydroxylapatite With Integral Lidocaine.

Background: Calcium hydroxylapatite with integral lidocaine, CaHA (+), received FDA approval in 2015 and CE mark approval in 2016. This formulation has been associated with significant pain reduction compared to CaHA. In a previous rheometry study, CaHA without lidocaine demonstrated higher viscosity and elasticity when compared with hyaluronic acid fillers.

Study Objective: To compare the rheological properties of CaHA (+) lidocaine to CaHA without lidocaine and to compare the rheological measures of CaHA (+) to 5 cross-linked hyaluronic acid (HA) fillers with integral 0.3% lidocaine.


Materials And Methods: The rheological properties of complex viscosity (η*) and elastic modulus (G') were measured for 2 types of CaHA fillers [CaHA without lidocaine and CaHA (+) with integral 0.3% lidocaine] and 5 HA fillers using an oscillation frequency sweep at a sheer stress of 5 pascal tau (Pa) and an interpolation of 0.7 Hz.


Results: CaHA with and without integral lidocaine demonstrate similar η* and G' measurements. CaHA with and without integral lidocaine demonstrates higher η* and G' compared with HA fillers with integral lidocaine.


Conclusion: CaHA with integral lidocaine has a similar rheological profile to CaHA without lidocaine: the highest η* and G' compared with available HA fillers with integral lidocaine.

J Drugs Dermatol. 2016;15(9):1107-1110.