Microneedle-mediated delivery of tizanidine for the treatment of spasticity

In parallel, HF MAPs were incorporated with external drug reservoirs designed to deliver TZN without leaving degradable polymers in the skin. Upon insertion, the hydrogel matrix imbibes interstitial fluid, swells, and establishes continuous aqueous conduits between the reservoir and the systemic circulation. Two reservoir formulations, a TZN amorphous solid dispersion and a lyophilised TZN hydrochloride (TZN HCl) patch, were developed and characterised, with evaluation of rehydration, dissolution behaviour, and physicochemical stability to define feasible long-acting release profiles.

The in vivo pharmacokinetic profile of HF-MAPs combined with TZN HCl lyophilised reservoirs was subsequently investigated. Collectively, these findings indicated that NC-loaded dissolving MAPs can enhance intradermal deposition and systemic availability of TZN, while HF-MAPs combined with lyophilised reservoirs provide a potential practical strategy for sustained transdermal administration. Microneedle technology offers a translational pathway to improve TZN pharmacokinetics, reduce dosing frequency, and ultimately support better patient adherence.

Beyond spasticity management, the platform is generalisable to poorly soluble drugs and can inform the design of future long-acting transdermal therapies. <br><br><i>Thesis is embargoed until 31 July 2031.</i>