Hersh E V, Maniar M, Green M, Cooper S A
University of Pennsylvania School of Dental Medicine, Department of Oral Surgery and Pharmacology, Philadelphia 19104-6003.
Anesth Prog. 1992;39(6):197-200.
The Lipospheres Bupivacaine Delivery System (bupivacaine-lipospheres) is a novel sustained-release local anesthetic preparation that has recently been made available for research purposes. This investigation compared the local anesthetic efficacy and safety of 2% bupivacaine-lipospheres, 0.5% bupivacaine plus 1:200,000 epinephrine, lipospheres plain, and physiologic saline following subcutaneous tail injection in the rat. A modified tail-flick paradigm was used to assess local anesthetic efficacy. Animals treated with 2% bupivacaine-lipospheres or 0.5% bupivacaine with epinephrine displayed significant antinociception (P < 0.05) compared to saline or lipospheres plain with 5 min of injection. Bupivacaine with epinephrine had an anesthetic duration of 30 min, whereas 2% bupivacaine-lipospheres had a duration of 3 hr. The local anesthetic blockade produced by both active solutions was completely reversible. All animals gained weight normally during the 1-wk course of the study, and there were no signs of local tissue toxicity at the injection sites. We conclude that 2% bupivacaine-lipospheres is a safe and efficacious local anesthetic preparation in this particular animal model. It possesses an onset of action that is a rapid as 0.5% bupivacaine with 1:200,000 epinephrine, and a duration that is six times longer.
脂质体布比卡因递送系统（布比卡因-脂质体）是一种新型的缓释局部麻醉制剂，最近已可供研究使用。本研究比较了2%布比卡因-脂质体、0.5%布比卡因加1:200,000肾上腺素、空白脂质体和生理盐水在大鼠尾皮下注射后的局部麻醉效果和安全性。采用改良的甩尾范式评估局部麻醉效果。与注射生理盐水或空白脂质体的动物相比，接受2%布比卡因-脂质体或含肾上腺素的0.5%布比卡因治疗的动物在注射后5分钟显示出显著的抗伤害感受（P < 0.05）。含肾上腺素的布比卡因麻醉持续时间为30分钟，而2%布比卡因-脂质体的持续时间为3小时。两种活性溶液产生的局部麻醉阻滞完全可逆。在为期1周的研究过程中，所有动物体重正常增加，注射部位没有局部组织毒性的迹象。我们得出结论，在这个特定的动物模型中，2%布比卡因-脂质体是一种安全有效的局部麻醉制剂。它的起效速度与含1:200,000肾上腺素的0.5%布比卡因一样快，持续时间长六倍。
