Fabrication of Microneedle Patches of Indomethacin Using 3DP Technology

Background: Indomethacin is a Nonsteroidal Anti-Inflammatory Drug (NSAID) that is frequently used for its pain-relieving, anti-inflammatory and fever-reducing properties. It is typically taken orally, but can also be administered rectally or intravenously in certain situations. As with all NSAIDs, indomethacin can have side effects, including gastrointestinal upset, headache, dizziness and skin rashes, the major ones being gastrointestinal bleeding and kidney problems, particularly associated with its prolonged use or at higher doses. Hence, to mitigate the adverse effects of the presently available oral medications, indomethacin needs an alternative way of delivery for local as well as systemic actions. Considering the barrier effects of skin to transdermal drug delivery, microneedle patches of indomethacin have been fabricated on 3D-printed molds as a viable alternative to normal transdermal patches to maximize the local and systemic uses of the drug as an anti-inflammatory agent. Materials and Methods: Microneedle and transdermal patches were prepared using the solvent casting method, with a total of eight formulations developed and characterized for parameters such as thickness, drug content and drug release. The patches underwent accelerated stability testing, followed by a skin irritation study conducted on rats to ensure safety. Additionally, a bioavailability study was performed to calculate pharmacokinetic parameters, including AUC, Cmax and Tmax. Results: Among the formulations, microneedle patch M3 and transdermal patch P3 demonstrated maximum drug release. The pharmacokinetic analysis revealed that M3 exhibited significantly higher values of AUC (2097.15 μg·hr/mL) and Cmax (93.44 μg/mL) compared to P3, which had an AUC of 1886.32 μg·hr/mL and Cmax of 90.41 μg/mL. Both patches had a Tmax of 12 hr. Conclusion: These findings indicate that microneedle patches of indomethacin offer a superior and innovative approach for anti-inflammatory applications, with improved drug release and bioavailability compared to transdermal patches. This study highlights the potential of microneedle patches for enhanced therapeutic outcomes, paving the way for further development and clinical exploration.