Research Article Effect of Modulated Alternating and Direct Current Iontophoresis on Transdermal Delivery of Lidocaine Hydrochloride Gaurav Bhatia and Ajay K. Banga Department of Pharmaceutical Sciences, College of Pharmacy, Mercer University, Atlanta, GA 30341, USA Correspondence should be addressed to Ajay K. Banga; banga ak@mercer.edu Received 9 February 2014; Accepted 1 May 2014; Published 15 May 2014 Academic Editor: Sandeep Nema Copyright © 2014 G. Bhatia and A. K. Banga. his is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. he objective of this study was to investigate the iontophoretic delivery of lidocaine hydrochloride through porcine skin and to compare the efects of modulated alternating and direct current iontophoresis. Continuous and modulated iontophoresis was applied for one hour and two hours (0-1 h and 4-5th h) using a 1% w/v solution of lidocaine hydrochloride. Tape stripping was done to quantify the amount of drug permeated into stratum corneum and skin extraction studies were performed to determine the amount of drug in stripped skin. Receptor was sampled and analyzed over predeined time periods. he amount of lidocaine delivered across porcine skin ater modulated direct current iontophoresis for 2 h was 1069.87 ± 120.03 g/sq⋅cm compared to 744.81 ± 125.41 g/sq⋅cm ater modulated alternating current iontophoresis for 2 h. Modulated direct current iontophoresis also enhanced lidocaine delivery by twelvefold compared to passive delivery as 91.27 ± 18.71 g/sq⋅cm of lidocaine was delivered ater passive delivery. Modulated iontophoresis enhanced the delivery of lidocaine hydrochloride across porcine skin compared to the passive delivery. Modulated alternating current iontophoresis for duration of 2 h at frequency of 1 kHz was found to be comparable to the continuous direct current iontophoresis for 1 h. 1. Introduction Lidocaine hydrochloride is a hydrophilic local anesthetic, which is widely used for topical anesthesia and other medical and surgical procedures including treatment of skin sores, lesions, and suturing of wounds [1]. It is also used as an antiarrhythmic drug [2]. It exerts local anesthetic efect by binding with voltage gated Na + channels at axonal membrane and prevents the transport of Na + across the channels, thus inhibiting the postsynaptic neuron from depolarization and stabilizes neuronal membrane [3]. he most common form of lidocaine administration is through intravenous or hypodermic injection, which causes pain and discomfort [4]. Transdermal delivery of lidocaine is a potential alternative route of administration. However, due to poor penetration through intact skin, the percutaneous application of lidocaine is limited [5]. Commercial products including EMLA cream (AstraZeneca) and Lidoderm (Endo Laboratories) are available for trans- dermal delivery of lidocaine. However, achieving efective analgesia requires the application of EMLA for 1-2h, which limits its use during emergency where fast onset of anes- thesia is desired making it less convenient to use during normal clinical procedures [6]. Several other formulations such as liposomes [5] or microemulsions have also been investigated to enhance the transdermal delivery. Polymeric liposomes have been shown to be efective in enhancing the transdermal delivery of lidocaine across the mouse skin. Bacterial cellulose membrane incorporated with lidocaine demonstrated lower permeation than conventional formu- lation through human epidermis [7]. A combination of short-term iontophoresis and microemulsion formulation signiicantly increased the lux and resulted in accumulation of large skin drug depot and short lag time in delivery of lidocaine through porcine skin. Studies have also reported that transdermal delivery of lidocaine has a possibility to be Hindawi Publishing Corporation BioMed Research International Volume 2014, Article ID 537941, 6 pages http://dx.doi.org/10.1155/2014/537941