Etidocaine Hydrochloride

Etidocaine hydrochloride was encapsulated into ionic gradient liposomes composed of hydrogenated soy phosphatidylcholine and cholesterol using a Design of Experiments approach. The optimized formulation achieved 41 percent encapsulation efficiency, remained stable for 180 days at 4°C, and showed evidence of drug interaction with the lipid bilayer by DSC and ¹H NMR. The liposomes promoted sustained drug release for approximately 24 hours and decreased the intrinsic toxicity of etidocaine to Schwann cells by 50 percent. In a Caenorhabditis elegans model, the formulation reduced toxicity by 25 percent. In rats, the liposomal formulation extended the anesthetic effect by one hour after infiltrative administration at clinically used concentration.