Pain Patch Versus Injections in the Treatment of Pain Associated With Shoulder Impingement Syndrome

Synera consists of a thin, uniform layer of a local anesthetic formulation with an integrated, oxygen-activated heating component that is intended to enhance the delivery of the local anesthetics. The drug formulation is an emulsion in which the oil phase is a eutectic mixture of lidocaine 70 mg and tetracaine 70 mg. The surface area of the entire Synera patch is approximately 50 cm2, 10 cm2 of which is active. The 40 cm2 perimeter is a medical grade adhesive. The Synera patches used in this study are the commercially available form.

Triamcinolone Acetonide is a synthetic glucocorticoid corticosteroid with marked anti-inflammatory action, in a sterile aqueous suspension suitable for intralesional and intra-articular injection. Each mL of the sterile aqueous suspension provides 40 mg of triamcinolone acetonide, with sodium chloride for isotonicity, 0.9% (w/v) benzyl alcohol as a preservative, 0.75% carboxymethylcellulose sodium, and a 0.04% polysorbate 80; sodium hydroxide or hydrochloric acid may have been added to adjust pH between 5.0 and 7.5. At the time of manufacture, the air in the container is replaced by nitrogen.