Microneedle Integrated Transdermal Patch for Fast Onset and Sustained Delivery of Lidocaine

Abstract

Lidocaine as an analgesic is of particular interest in both acute and chronic pain conditions and is used via injections or transdermal patches. While injections are associated with problems such as patient incompliance, topical administration of lidocaine using patches is less efficient due to variability of drug absorption among individuals, slower drug permeation through the skin, and hence a resultant undesirable delay in analgesic effects. To address this clinical problem, we developed a microneedle integrated transdermal patch (MITP), using a photolithography based process, in which microneedles create micrometer-sized channels in the skin to deliver lidocaine rapidly, while the reservoir patch holding the bulk of the drug enables higher drug loading and carries on to release the drug for prolonged periods. We demonstrated a new approach of drug delivery using microneedles, where drugs diffuse out of microneedles through the porous channels left by dissolving drug particles. MITP was shown to be able to encapsulate up to 70 mg of lidocaine. In vitro permeation through rat skin demonstrated that MITP delivered a significantly higher amount of lidocaine than a commercial patch and with a faster onset of drug permeation.

Lidocaine carboxymethylcellulose with gelatine co-polymer hydrogel delivery by combined microneedle and ultrasound

“…Research has shown significant increases in skin permeability using optimized MNs when considering factors of MN length, number of MNs, the length and width aspect ratio and surface area (Al-Qallaf & Das, 2008Olatunji et al, 2012Olatunji et al, , 2013Guo et al, 2013). It has been suggested that MNs can be adapted to aid lidocaine delivery yielding many fold increase in delivery rate (Kwon, 2004;Li et al, 2008;Wilson et al, 2008;Zhang et al, 2012a, b;Kochhar et al, 2013;Ito et al, 2013;Nayak et al, 2014).…”

Polymeric Microneedle Array Fabrication by Photolithography

“…More interestingly, it can be used as a combination of the delivery system and device, as the therapeutic compounds may be encapsulated (by mixing or solubilizing in prepolymer solution) during the fabrication of MNs. 5,6,17 The solubility of the added compound inside the prepolymer solution should be taken into consideration as the MN characteristics, e.g., MN strength, may change.…”

Accelerating Topical Anaesthesia Using Microneedles

“…Coated [28] , encapsulated [29] , and dissolving [31] microneedles all provide novel drug delivery systems that can potentially facilitate increased levels of anaesthetic permeation. Nayak et al [26] have also used a novel topical lidocaine formulation in combination with microneedles to accelerate anaesthetic permeation.…”

“…Previous studies have shown that microneedles can improve the permeation of lidocaine into the skin. These studies used microneedles to either (i) pre-treat skin before the topical application of a lidocaine hydrochloride solution [25] or hydrogel formulation [26,27] , (ii) deliver lidocaine from a dry-coated microneedle surface [28] , or (iii) encapsulate lidocaine within a microneedle patch [29] . The formulations used in these studies are currently not clinically approved for human use.…”