Mepivacaine: a potential safer anesthetic compound for dermal fillers injections

Anti-ageing treatments being now popular, aesthetic practices evolved as much, and range of soft-tissue fillers have been developed, mostly consisting of crosslinked hyaluronic acid-based gels. They target different indications, and, as such, different skin tissue layers. Using a needle or cannula, filling products’ injections, although minimally invasive, can remain painful for patients, especially in sensitive areas such as lips. One cornerstone of painless rejuvenation treatments was the incorporation of a local anesthetics into dermal fillers formulation, around the 2000’s¹ . The gold standard anesthetic product to minimize discomfort while being injected with a hyaluronic acid-based gel is lidocaine. This pain reliever has been successfully introduced at 0,3% in Hyaluronic Acid (HA) fillers and is commercially used worldwide² .

Teoxane investigated mepivacaine as a potential new local anesthetic agent to replace lidocaine in HA fillers. The influence of mepivacaine on filler mechanical properties, stability, degradability, release profiles and pharmacokinetics was assessed. 
Study protocol used Teosyal^® RHA fillers, either with lidocaine or mepivacaine for comparison purpose. Mechanical properties of studied fillers were then analyzed after final packaging and sterilization.

Elastic modulus G’, Strength and Stretch scores^* showed no statistical variation on both formulations, therefore meaning that the addition of lidocaine or mepivacaine had no impact on rheological properties of each product.

Regarding aesthetic practice, extrusion force was low independently of the addition of lidocaine of mepivacaine, allowing easy injections for healthcare practitioners.

Identical trend were collected regarding life stability of products in presence of lidocaine and mepivacaine, allowing a 3-years period for storage. This data was supported by the persistence of the phase angle in both products, guaranteeing alike clinical results either with lidocaine or mepivacaine.

Release profiles showed steeper curves for mepivacaine, suggesting anesthetic effects occurred faster, and therefore, a potential clinical benefit for mepivacaine over lidocaine. 

Additionally, no influence of both anesthetics was reported in the ability of dermal fillers to be degraded in case of adverse events. 
Interestingly, mepivacaine shown lower solubility also confers a diminished risk of toxic reactions.

Considering these properties, mepivacaine is a reliable candidate to be incorporated in soft-tissue fillers for pain relief during hyaluronic acid filler injection, suggesting it could even bring a clinical benefit.

You can read the full article by clicking here : https://pubmed.ncbi.nlm.nih.gov/35893810