Sustained Acoustic Medicine Increases Local Circulation with a Diclofenac Delivery Patch: A Randomized Placebo Controlled Study

Michael Roberge^1*Anthony Scanzuso²Tabitha Hendren³Mia Egmont⁴Julia Zarkar^3,4

• ¹Compound Solutions, INC, Monroe, United States
• ²ZetrOZ Systems, Trumbull, United States
• ³University of California, Santa Barbara, Santa Barbara, California, United States
• ⁴University of Connecticut, Storrs, Connecticut, United States

Background: Sustained Acoustic Medicine (SAM) is a non-invasive long-term wearable device that delivers localized long duration high-frequency continuous ultrasound. SAM's biomechanical and diathermic stimuli enhance local circulation and oxygenation, accelerate tissue healing, and alleviate pain. The sonophoresis effects of SAM further improve transdermal drug delivery. Diclofenac is a topical Nonsteroidal anti-inflammatory drug for treating localized musculoskeletal (MSK) pain. Its efficacy is significantly dependent on skin porosity. This study aims to determine the diathermic effects of SAM and diclofenac on localized blood circulation.Methods: Sixty-four healthy participants were randomly assigned to four groups (Active SAM group: n=32, Placebo SAM group: n=32): A) Coupling gel + placebo SAM), B) Coupling gel + active SAM, C) 2.5% Diclofenac gel + placebo SAM, and D) 2.5% Diclofenac gel + active SAM. Both forearms were treated with a placebo and active SAM devices for 1 hour. The blood flux (perfusion units, PU) and temperature (degrees centigrade) change were recorded at 10-minute intervals for 60 minutes using highlaser-power Doppler flowmetry. Blood circulation and temperature were recorded and reported (Clinical trial Identifier: NCT06510062).Results: SAM increased blood flow significantly over 60 minutes by 19.2 PU (p<0.0001) with coupling patch and 18.6 PU with 2.5% diclofenac patch (p<0.0001) versus placebo. Surface level tissue temperature increased by ∆2.4 ℃ (p<0.0001) with gel coupling patch and ∆2.2℃ (p<0.0001) with 2.5% diclofenac patch versus placebo ultrasound treatment (p<0.0001). There was no significant difference between standard coupling ultrasound gel and 2.5% diclofenac gel in blood flow and temperature. SAM provided a significant temperature increase at 20 minutes and a circulation increase at 10 minutes, which remained for the duration of the 60 minutes. All participants completed the study with no adverse events.SAM treatment significantly increases local blood circulation after 10 minutes, increases temperature after 20 minutes, and sustains the effects of SAM's stimulation. The 2.5% diclofenac gel does not affect SAM's biological effects to increase local circulation. The study concludes that the application of diclofenac does not affect the diathermic properties of SAM exposure while enhancing the efficacy of diclofenac delivery through sonophoresis.