Novel tip-loaded dissolving and implantable microneedle array patches for sustained release of finasteride

Finasteride (FND) is a competitive inhibitor of 5α-reductase, an enzyme involved in benign prostatic hyperplasia
(BPH) and androgenic alopecia. FND is administered in oral, often lifelong treatments, increasing the pill burden
of polymedicated patients. Microneedle array patches (MAPs) are minimally invasive devices that painlessly
pierce the outermost layers of the skin, forming slowly-dissolving drug depots in the dermis, which can release
drugs over weeks or months, making this platform an attractive, patient-friendly option for long-term treatments.
This work describes the development of long-acting dissolving and implantable PLGA MAPs aimed for systemic
release of FND for at least two weeks. Mechanically strong tip-loaded MAPs with pyramidal geometry were
obtained using micromoulding methodology. In vitro studies revealed that the dissolving and implantable MAPs
were able to release the drug for over 7 and 14 days, respectively. Skin deposition experiments in Franz cells
demonstrated that after 24 h, dissolving and implantable MAPs were able to deposit 629.00 ± 214.54 μg and
1861.64 ± 383.30 μg of FND in the skin, respectively. On the other hand, transdermal permeation studies
showed that both formulations produced a slow release of the drug to the receptor compartment of the Franz
cells, with dissolving and implantable MAPs releasing 90.43 ± 6.20 μg and 27.80 ± 3.94 μg of FND after 24 h.
The formulations described here could be an alternative to current oral treatments, having the potential to
deliver the drug for extended periods, simplifying the treatment of BPH and androgenic alopecia.