Study of a combined percutaneous local anaesthetic and the TDS system for venepuncture.

Transdermal Delivery System (TDS) is a liquid formulation which can be applied to the skin via a metered pump spray to deliver drug across skin. This placebo controlled, double blind trial compared anaesthetic properties of two TDS systems (TDS alpha and TDS beta) with placebo. The active and placebo treatments were applied to the dorsum of the hands, bilaterally and simultaneously for 5 min on 100 healthy volunteers. Following cannulation, pain perception was measured using the verbal rating score (VRS) and visual analogue score (VAS). Lidocaine plasma levels were assessed at 0 and 2 h. The VRS and VAS results show that TDS beta significantly decreased pain score compared to placebo (p < 0.02). Blood lidocaine at 2 h post application was also higher for TDS beta than for TDS alpha, suggesting that a 5 min application of TDS beta was effective in delivering local anaesthetic and accelerating the onset of skin anaesthesia prior to venous cannulation in adults.