In vivo and qualitative studies investigating the translational potential of microneedles for use in the older population

Abstract

Microneedles (MNs) are a novel transdermal drug delivery platform, rapidly progressing from a substantive evidence base, towards commercialisation. As part of this transition, it is important to consider the future use of MNs by older people in order to ensure optimal therapeutic outcomes for this unique and increasing population group. This paper, therefore, considers the use of MNs by those aged over 65 years, investigating insertion parameters in ageing skin, alongside the feasibility and acceptability of the technology. Hydrogel-forming MN arrays were applied to seven subjects aged over 65 years, with breach of the stratum corneum confirmed using optical coherence tomography. Insertion depths recorded in each case were similar to a comparative group, aged 20–30 years. Skin recovery was, however, demonstrated to occur at a slower rate in the older subjects, as measured using transepidermal water loss. Qualitative methods, including focus groups and semi-structured interviews, were employed to collect the views and opinions of older people and community pharmacists respectively. The overall consensus was positive, with a number of benefits to MN-mediated drug delivery identified, such as reduced dosing frequency, improved adherence and an alternative delivery route where oral or injectable medication was precluded. Concerns centred on practical issues associated with age-related functional decline, including, for example, reduced dexterity and skin changes. The presentation of this work collectively provides the first convincing report of the importance of further translational research in this area to support future MN use in older people, ensuring an age-appropriate delivery platform.

Evaluation of the clinical impact of repeat application of hydrogel-forming microneedle array patches

“…Despite their mechanism of action requiring the puncture of the skin's protective stratum corneum barrier, microneedles have been shown not to cause infection, even when the skin is not pre-cleansed, whether the microneedles themselves were sterilised or not [17,31,32]. Importantly, erythema and disruption in skin barrier function caused by the initial skin puncture have also been shown to resolve quickly, generally within less than 24 h for barrier recovery and less than 7 days for erythema [1,20,21,34].…”

“…Recently, we have shown that repeat insertion into mouse skin in vivo, followed by subsequent retention for 24 h did not lead to disturbance in skin appearance, skin barrier function or biomarkers of infection, immunity, inflammation or allergy [19]. While we have already shown on numerous occasions that single applications of these MAPs cause no adverse effects in humans [1,14,16,20,21], the vital next step in translation of this technology is to now demonstrate, for the first time, the safety of repeat application, with prolonged wear, in human volunteers.…”

Polymeric Microneedle Arrays: Versatile Tools for an Innovative Approach to Drug Administration

“…[60,61] The field of MN application is so large that no limits can be provided in principle, and probably most applications have yet to be implemented. [60,61] The field of MN application is so large that no limits can be provided in principle, and probably most applications have yet to be implemented.…”

Exploration into the opinions of patients with HIV, healthcare professionals and the lay public of the use of microneedles in clinical practice: highlighting the translational potential for their role in HIV infection

“…Previous studies investigating perceptions surrounding MN technology have yielded positive findings with various potential end-user demographics including members of the lay public (LP), various healthcare professionals (HCPs) children and the elderly, being able to identify a number of benefits of MN technology, whilst also highlighting potential suggestions where improvements may be made [13][14][15][16]. However, there has been no study to date, that has specifically considered the views and opinions of patients with HIV, surrounding the use of MNs for drug delivery, despite the complexities of current ART.…”