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

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.