Preparation and optimization of lidocaine transferosomal gel containing permeation enhancers: a promising approach for enhancement of skin permeation

Aim: To develop the topical gel containing transferosomal lidocaine as alternative to painful local anesthetic injection. Materials and methods: The transfersomes were prepared by film hydration technique using soybean phosphatidylcholine and cholesterol. The prepared transfersomes were evaluated for the morphology, drug loading, %EE, particle size and in vitro release. The transferosomal gel of lidocaine was prepared using HPMC k15 as gelling agent and propylene glycol, dimethyl sulfoxide (DMSO), and polyamidoamine dendrimer third generation (PAMAM G3) solutions were used as permeation enhancer. The formulated gels were evaluated for pH, viscosity, drug content and ex-vivo permeation of the gel. The analgesic effect of the formulation was tested using tail flick test. Results: The transfersomes showed that transfersomes (F4) had the highest entrapment efficiency (%EE) approaching 79.87 +/- 2.35, low particle size 179.5 nm, and zeta potential of -43.5 +/- 4.74 mV. According to the rat tail flick test, the AUC(0-90 minutes) of the control formulation (lidocaine solution, A) was 352.32 +/- 5.87 seconds minutes. While the maximum AUC(0-90 minutes) value was found to be 570.5 +/- 6.81 seconds minutes for gel formulation (F) containing transfersomal lidocaine with PAMAM G3 dendrimer as permeation enhancer. In this case, the local anesthetic efficacy was increased by 1.62-folds as compared to control formulation. Conclusion: From the present study, it can be concluded that the topical gel loaded with transfersomal lidocaine shows enhanced skin permeation effect along with increase in local anesthetic action of lidocaine.