Rasagiline mesylate-based microneedle patches: A patient-friendly treatment regimen for Parkinson's disease

Parkinson's disease is a progressive neurodegenerative disorder, with rasagiline mesylate (RM), a potent MAO-B inhibitor, used to manage symptoms. However, oral RM administration often leads to gastrointestinal side effects, reducing patient compliance. This study explores dissolving microneedles (DMNs) and hydrogel-forming microneedles (HMNs) for transdermal RM delivery. DMNs exhibited uniform drug distribution, while HMNs showed even polymer dispersion and sharp needle tips. The formulated DMNs and HMNs demonstrated less than 15 % height reduction against 32 N pressure for 30 s, and insertion studies using an artificial Parafilm® M indicated sufficient needle mechanical properties to reach the dermal microcirculation. The selected DMNs drug content was 1.41 ± 0.11 mg with ∼ 70 % of RM retained in the baseplate due to drug migration during manufacturing. In situ dissolution studies showed that, this formulation fully dissolved within 60 min when applied to full-thickness neonatal porcine skin. Stability assessments confirmed that the active compound remained stable with no significant degradation after 4 weeks of storage for DMNs and reservoirs. In vitro permeation studies demonstrated that optimum DMNs formulation delivered approximately 928.2 ± 198.8 μg of the active compound over 24 h, corresponding to about 65 % of its content. HMNs delivered 6.44 mg and 18.32 mg of RM at 6 h and 24 h, corresponding to ∼ 20 % and ∼ 60 % delivery, respectively. These findings highlight the potential of microneedles as a viable transdermal RM delivery system, offering an alternative to oral administration, while maintaining controlled drug release and stability.