Design and Development of Lidocaine Microemulsions for Transdermal Delivery

Abstract

Topical administration is a preferable choice for local anesthetic delivery. Microemulsions have shown great effectiveness for transdermal transport of lidocaine. However, fabrication of microemulsions containing highly concentrated lidocaine (10%) to provide an extended local anesthetic effect is still a challenge. This study investigated the feasibility of using microemulsions for transdermal delivery of a high dosage of lidocaine (10%). At first, eutectic mixtures by kneading lidocaine with thymol were tailored to form a lipophilic solution, then the mixtures were readily incorporated into the oil phase of microemulsions after addition of proper surfactants and cosurfactants. The physicochemical properties, the skin permeation, local anesthetic efficacy, and the irritation experiment of the developed microemulsions were evaluated. The optimum composition was as follows: 12% of ethyl oleate as oil phase, 28% of the mixed surfactant, and cosurfactant (polyoxyl 15 hydroxystearate and ethanol) and 60% of the aqueous phase. The average particle size was about 13 nm. The transmission electron microscope (TEM) studies revealed almost homogeneous spherical globules without aggregation. The Fourier-transform infrared spectroscopy (FTIR) results highlighted the drugs homogeneously dispersed in the microemulsions. In vitro skin permeation and in vivo anesthesia effect evaluation indicated that microemulsions can enhance and extend the anesthetic effect of lidocaine. The irritable results indicated that the microemulsions had the better biocompatibility and the negligible influence on the dermal. Therefore, incorporating the eutectic mixtures into microemulsions could be proposed as an attractive choice and a promising transdermal delivery strategy for the future topical anesthetic therapy.

Fabrication of Alginate-Based O/W Nanoemulsions for Transdermal Drug Delivery of Lidocaine: Influence of the Oil Phase and Surfactant

“…Additionally, they are favorable for their ease of preparation. Moreover, it is proposed that their use for transdermal drug delivery enhances the permeability profile due to the smaller droplet size which increases the contact with the membrane improving the delivery of the encapsulated drug [ 55 , 56 ]. However, it has been reported that nanoemulsions achieve a higher degree permeation and drug loading capacity as compared with microemulsions [ 10 , 25 , 57 ].…”

“…The solution was then filtered and kept in Franz cell to assess permeation profile. It is noticed that the use of nanoemulsion formulation produced an enhanced permeation as compared with the saturated solution which could be attributed to the nano-sized droplets which would have an increased surface area that can increase the contact of the encapsulated drug with the stratum corneum producing improved permeability for transdermal delivery [ 55 ]. As discussed earlier, the change in flux could be as a result of the interactions between the surfactant and membrane or the drug and surfactant.…”

“…This was achieved at a lower lidocaine concentration in the nanoemulsion which is 0.24% as compared to that used in literature which is 10%. Wang et al showed a higher flux value by approximately one-fold because the concentration of lidocaine used was 10% and permeation profile was studied on mice skin which causes an overestimation in permeability [ 55 ]. Nanoemulsions used in this study showed a potential by providing higher flux of lidocaine at lower lidocaine concentrations.…”

Transdermal Delivery of Lidocaine-Loaded Elastic Nano-Liposomes with Microneedle Array Pretreatment

“…Recent data indicate that surfactants enhance the transdermal delivery of LidH-loaded vesicles [ 12 , 30 , 31 ]. The results of this study showed that ENL formulations deliver significantly more LidH in 6 h than SLN formulations, probably because the surfactants effectively decrease the surface tension at the interface of oil and water, and ENLs can readily deform during diffusion [ 31 ]. This characteristic facilitates a deep diffusion of ENL in the skin and LidH release.…”

Jojoba oil-based microemulsion for transdermal drug delivery

“…( 41 42 ) and Wang et al . ( 43 ). This could be explained by the differences in the microemulsion composition and by the penetration enhancement effect of jojoba oil itself.…”