Electroporation technique for joint pain - Pilot feasibility study on TMD patients.

Objective(s): It is well appreciated that traditional analgesic delivery routes used to treat pain associated with temporomandibular disorder (TMD) often have harmful unintended side effects as a consequence of systemic distribution. Further, localized delivery of analgesic medication via intra-articular injections involves a different set of issues limiting their clinical viability. As an option, transdermal analgesic delivery provides for prolonged pain relief and flexibility in dose administration, while limiting systemic exposure and minimizing adverse events. Incorporation of a novel electroporation technique may further increase transdermal drug penetration into synovial tissue/fluid and enhance pain reduction. The present feasibility study compares the effectiveness of an electroporation-enhanced transdermal application of diclofenac sodium to a conventional intra-articular injection of triamcinolone acetonide suspension (corticosteroids) to treat patients with TMD associated pain.

Methods: Pre- and post-treatment maximal incisal mouth opening (MIO), pain visual analog scale (VAS) and surface electromyography (EMG) of 22 patients treated with electroporation-enhanced diclofenac and 37 patients treated with corticosteroids injections were collected and analyzed.

Results: In general, patients treated with electroporation exhibited better results in terms of pain improvement (corrected p-value = .01) compared to the standard treatment, but both methods were similarly effective for improvement of MIO (corrected p-value = .71) and improvement of all EMG indices (corrected p-values ≥ .05).

Conclusion: The enhancing effect of electroporation in transdermal delivery of diclofenac sodium was demonstrated by decreased pain, increase MIO and EMG improvement to normal values. Its analgesic and inflammatory results are comparable with standard treatment offered by corticosteroids.