Iontophoresis-assisted pediatric transdermal delivery of ropivacaine to enhance anesthetic effect

Abstract

Purpose: To formulate novel transdermal patches of ropivacaine (RPV) and enhance its anesthetic activity using iontophoresis technique. Methods: Solvent casting method was used for the development of the transdermal patches with the aid of hydroxypropyl methylcellulose (HPMC) and polyvinyl alcohol (PVA) polymers. The patches were characterized for appearance, clarity, smoothness, thickness, average weight of patches, folding endurance, RPV uniformity, moisture absorption and tensile strength. The anesthetic effect of ropivacaine patches were evaluated in a healthy pediatric population divided into two groups. One group was merely applied with the patch while the other group received the patch using LidoSite applicator. The anesthetic effect was assessed based on hot pain, cool sensation and warm sensation. Results: The patches were smooth and transparent, about 0.29 mm in thickness, having a tensile strength of 0.51 kg/cm2 and showed in-vitro drug release of 68.94 to 96.83 %. The formulation did not exert any undesirable local skin effects, and produced minimum pain intensity. The depth of anesthesia was higher for the patch formulation with iontophoresis than for the conventional system. Conclusion: The findings point to the superiority of RPV transdermal patches when applied with iontophoretic device as against the conventional application.