Influence of Liposomal Local Anesthetics on Platelet Aggregation In Vitro

Abstract

We assessed the effect of local anesthetics (LA) from different families such as esters (benzocaine), linear aminoamides (lidocaine) and cyclic aminoamides (bupivacaine) on the platelet aggregation induced by ADP. Liposomal formulations of the three LA, prepared with egg phosphatidylcholine:cholesterol α‐tocopherol, were also tested. The three LA were able to inhibit platelet aggregation induced by ADP, in the following order: bupivacaine > lidocaine > benzocaine. After encapsulation into liposomes the inhibitory effect increased for all anesthetics studied, showing that aggregation tests could be used to assess the toxicity of new drug formulations.

Keywords: :

• Liposomes
• Local anesthetics
• Platelet aggregation
• ADP

Acknowledgments

This research was supported by Fundação de Amparo à Pesquisa do Estado de São Paulo (Proc. # 96/1451–9). LMAP (Grant # 98/15936–0) was the recipient of a fellowship from FAPESP; EP is the recipient of a fellowship from CNPq.