Purpose <p>Oral clonidine therapy is associated with fluctuating plasma drug concentrations, frequent dosing, and poor adherence. Existing transdermal patches exhibit delayed onset and local skin irritation. This study aimed to develop and optimize clonidine dissolving microneedle patches using a Quality by Design (QbD) framework and to evaluate their potential for sustained systemic delivery.</p> Methods <p>We used a 2⁴ full factorial design to study the effects of hyaluronic acid concentration, glycerol concentration, clonidine HCl loading, and drying time at two levels on critical quality attributes. Sixteen formulations of clonidine-loaded dissolving microneedle patches were prepared using a solvent-casting method. The optimized formulation was evaluated through in vitro, ex vivo, and in vivo studies.</p> Results <p>The optimised formulation exhibited sufficient mechanical strength, insertion efficiency, rapid dissolution, and efficient drug release. Ex vivo studies demonstrated improved drug flux, substantial intradermal drug retention and permeability. Compared to oral clonidine delivery, the optimised formulation exhibited a sustained pharmacokinetic profile with a delayed Tmax (3.83-fold delay), higher systemic exposure (2.45-fold increase), a 1.86-fold prolongation in half-life, and a 1.81-fold increase in mean residence time, without a disproportionate increase in Cmax (1.15-fold). A mechanistic relationship between in vitro release, ex vivo permeation, and in vivo pharmacokinetic exposure was suggested. Safety evaluation confirmed the absence of significant acute dermal irritation.</p> Conclusion <p>Overall, the results support that clonidine-loaded dissolving microneedle patches appear to be a safe and promising transdermal delivery system. Beyond clonidine delivery, this study suggests that dissolving microneedles may enable modulation of systemic drug exposure, as prolonged pharmacokinetic profiles were observed despite the rapid dissolution of the microneedles.</p>