Efficacy of A Non-Invasive Botulinum Toxin Microneedle Pad for the Treatment of Secondary Raynaud's Phenomenon

Raynaud's Phenomenon (RP), a vasospastic disorder causing digital ischemia and potential tissue necrosis, is effectively treated with Botulinum Toxin Type A (BTX-A) in refractory cases. However, standard administration requires painful, invasive injections that risk infection and localized muscle weakness. To address these limitations, this randomized, placebo-controlled, parallel-group study evaluates a microneedle delivery system designed to reach the dermis while avoiding systemic circulation. By penetrating 70-80% of their height, these microneedles aim to improve hand function and symptom scores for adult systemic sclerosis patients through a more comfortable, portable, and less invasive method that increases delivery surface area while minimizing pain.

Inclusion Criteria: 1. SSc patients aged between 18 and 70 years 2. Diagnosed according to ACR/EULAR 2013 classification criteria20 3. Having RP with/without DU on fingers or toes 4. Understand and able to read and write Thai language 5. Stable steroid, immunosuppressant, and vasodilator including CCB, PDE5i for at least 4 weeks before enrollment Exclusion Criteria: 1. History of allergy or hypersensitivity to Botulinum toxin or ISDN 2. Overlap with other connective tissue diseases 3. Documented having peripheral arterial disease or vasculitis that affected vascular supply of fingers or toes 4. Current use of 2% ISDN cream for treatment of RP 5. Current use vasoconstrictor or medication that has vasoconstrictor effect such as ergotamine sulfate, beta-blocker 6. Pregnancy and lactating patients 7. Bedridden and confined to no self-care 8. Evidence of active malignant disease 9. Active infection or sepsis 10. Localized infection of hand 11. Impaired of intrinsic muscle hand function 12. Active smoker 13. Prior upper extremity vascular surgery, including surgical sympathectomy within 1 month before enrollment