Abstract
Microneedles are emerging drug delivery methods for painless treatment. The current study tested dissolving microneedles containing lidocaine (Li-DMN) for use in local anesthesia. An Li-DMN patch was fabricated by centrifugal lithography with carboxymethyl cellulose as a structural polymer and assessed for physical properties by optical microscopy and a fracture force analyzer. The biocompatibility was evaluated by a histology section in vitro and by ear thickness in vivo. The efficacy of the Li-DMN patch was assessed by electrophysiological recordings in primary cultured sensory neurons in vitro and a von Frey test on rats’ hind paws in vivo. The physical properties of the microneedle showed enough rigidity for transdermal penetration. The maximal capacity of lidocaine-HCl in the Li-DMN patch was 331.20 ± 6.30 µg. The cytotoxicity of the dissolving microneedle to neuronal cells was negligible under an effective dose of lidocaine for 18 h. Electrophysiological recordings verified the inhibitory effect of the voltage-gated sodium channel current by the Li-DMN patch in vitro. A skin reaction to the edema test and histologic analysis of the rats’ ears after application of the Li-DMN patch were negligible. Also, the application of the Li-DMN patch reduced the nocifensive behavior of the rats almost immediately. In conclusion, the dissolving microneedle patch with carboxymethyl cellulose is a promising candidate method for the painless delivery of lidocaine-HCl.
Highlights
Local anesthetic drugs block the transmission of nerve impulses by the inhibition of voltage-gated sodium channels (VGSCs) [1,2]
dissolving microneedles (DMNs) patches with or without lidocaine, and a lidocaine cartridge used in dental clinics were diluted in serum-free Dulbecco’s Modified Eagle Medium (DMEM) media with an equal concentration of lidocaine, and F11 cells were treated on each group for 2, 3, 6, 12 and 18 h
The cell viability is expressed as the ratio value of (ODtest−ODblank)/(ODcontrol−ODblank), where ODtest is the optical density of the cells exposed to the test solutions, ODcontrol is the optical density of lidocaine-untreated cells and ODblank is the optical density of the wells without cells
Summary
Local anesthetic drugs block the transmission of nerve impulses by the inhibition of voltage-gated sodium channels (VGSCs) [1,2]. Topical creams or sprays containing local anesthetics have been developed as a means to avoid needle injections [3,4,5,6] These needleless topical slow agents gained popularity for their convenience in the relevant application. Penetration of the stratum corneum, the outermost skin barrier, by microneedles was presumed to assist the permeation of topical local anesthetics at the epidermal layer [9]. This approach required a separate application of the microneedles and topical anesthetics. The safety and efficacy of the Li-DMN patch were confirmed and compared with the topical anesthetics for the rapid and effective anesthetics in the rodent model in vivo
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
