Biodegradable polymeric insulin microneedles – a design and materials perspective review

Abstract

Microneedle (MN) delivery devices are more accepted by people than regular traditional needle injections (e.g. vaccination) due to their simplicity and adaptability. Thus, patients of chronic diseases like diabetes look for alternative pain-free treatment regimens circumventing regular subcutaneous injections. Insulin microneedles (INS-MNs) are a thoughtfully researched topic (1) to overcome needle phobia in patients, (2) for controlled delivery of the peptide, (3) decreasing the frequency of drug administration, (4) to ease the drug administration procedure, and (5) thus increasing patient adherence to the treatment dosage regimes. MNs physically disrupt the hard outer skin layer to create minuscule pores for insulin (INS) to pass through the dermal capillaries into the systemic circulation. Biodegradable polymeric MNs are of greater significance for INS and vaccine delivery than silicon, metal, glass, or non-biodegradable polymeric MNs due to their ease of fabrication, mass production, cost-effectiveness, and bioerodability. In recent years, INS-MNs have been researched to deliver INS through the transdermal implants, buccal mucosa, stomach wall, intestinal mucosal layers, and colonic mucosa apart from the usual transdermal delivery. This review focuses on the design characteristics and the applications of biodegradable/dissolvable polymeric INS-MNs in transdermal, intra-oral, gastrointestinal (GI), and implantable delivery. The prospective approaches to formulate safe, controlled-release INS-MNs were highlighted. Biodegradable/dissolvable polymers, their significance, their impact on MN morphology, and INS release characteristics were outlined. The developments in biodegradable polymeric INS-MN technology were briefly discussed. Bio-erodible polymer selection, MN fabrication and evaluation factors, and other design aspects were elaborated.

Recent progress of polymeric microneedle-assisted long-acting transdermal drug delivery

“…When promoting the application of MNs, the sterility and bacterial endotoxin should be carefully checked to avoid clinical infection [ 90 ]. Moreover, the frequency of MNs administration should be evaluated carefully for diabetic patients, given the small volume of the moulds and the small amount of insulin loading [ 91 ].…”

“…Health and supervision departments should guide production industries to establish production process procedures and product quality standards suitable for this dosage form in accordance with Good Manufacturing Practice (GMP), to ensure the quality, consistency, and repeatability of the product [ 129 ]. Regulatory agencies require that large-scale production must be strictly sterile to prevent the occurrence of infection, which puts forward higher requirements for large-scale production manufacturers [ 91 , 139 ] Finally, on the user’s view, it is necessary to establish the description of the administration method or the standard medication device to ensure the consistency of the dosage. This will accelerate effective clinical translation after product development.…”

Polymeric Microneedles for Health Care Monitoring: An Emerging Trend

“… 33 − 40 Different review articles have also been published covering the developments in ISF sampling, MN-based sensors/wearables, and wearable electrochemical sensors. 27 , 41 − 48 Although there are plenty reviews focused on the application of polymeric MNs for drug delivery applications, 49 − 57 there are only a few covering the use of polymeric MNs for health monitoring. 30 , 58 As such, we devised this review to summarize the work that has been recently published on this topic and provide an outlook on the role of polymeric MNs in diagnostics and its potential for the future of the healthcare market.…”

“…During the last decades, several MN reviews have been published to cover the wide depth and breadth of MN technology in the drug delivery and cosmetics sectors. − Different review articles have also been published covering the developments in ISF sampling, MN-based sensors/wearables, and wearable electrochemical sensors. ,− Although there are plenty reviews focused on the application of polymeric MNs for drug delivery applications, − there are only a few covering the use of polymeric MNs for health monitoring. , As such, we devised this review to summarize the work that has been recently published on this topic and provide an outlook on the role of polymeric MNs in diagnostics and its potential for the future of the healthcare market. We start with a discussion of the types of MNs and their fabrication approaches and then present a detailed overview of the recent work published on the use of MNs for diagnostics.…”