Brigham Young University, Provo, UT, USA.
J Athl Train. 2011 May-Jun;46(3):277-81. doi: 10.4085/1062-6050-46.3.277.
In a recent study, we were unable to measure lidocaine in the human calf at a 5-mm depth via iontophoresis. We surmised that this might be due to a lack of epinephrine in the compound. Because epinephrine is a vasoconstrictor, it might allow the drug to pass beyond the capillaries and be delivered to the deeper tissues.
To determine if iontophoresis could deliver lidocaine with epinephrine 5 mm under the surface of human skin, as measured by microdialysis.
Descriptive laboratory study.
Therapeutic modalities research laboratory.
Ten volunteers (5 males, 5 females; age, 15-28 years) with less than 5 mm of adipose tissue in the area we measured and with no allergies to lidocaine participated. The measurement area had been free of any injury, swelling, or infection for at least 3 months before the study.
INTERVENTION(S): We inserted a microdialysis probe 0.5 cm under the skin of the right lower leg. Next, microdialysis was performed through this area for 60 minutes, which allowed local skin blood flow to return to baseline. We then performed iontophoresis at 40 mA/min using 2 mL of 2% lidocaine. Iontophoresis was performed over this area for 10.5 minutes to collect the lidocaine samples. After this stage, the electrode was left in place for another 50 minutes for a total of 60 minutes.
MAIN OUTCOME MEASURE(S): The samples of the drug were analyzed via reverse-phase high-performance liquid chromatography (RP-HPLC) in the chemistry department.
The RP-HPLC analysis confirmed the presence of lidocaine in all 10 participants. The mean concentration of lidocaine detected at the 5-mm depth was calculated as 3.63 mg/ mL (greater than 18% of delivered concentration).
We found that 2% lidocaine can be delivered up to 5 mm below the surface of the skin when the drug compound contains epinephrine and when passive delivery occurs for at least 50 minutes after the active delivery has terminated.
在最近的一项研究中，我们无法通过离子电渗法在人体小腿 5 毫米深度处测量利多卡因。我们推测这可能是由于复方制剂中缺乏肾上腺素。由于肾上腺素是一种血管收缩剂，它可能允许药物通过毛细血管并输送到更深的组织。
通过微透析确定含有肾上腺素的离子电渗法是否可以将利多卡因输送到人体皮肤表面以下 5 毫米处。
描述性实验室研究。
治疗方式研究实验室。
10 名志愿者（5 名男性，5 名女性；年龄 15-28 岁）参与了研究。他们在我们测量的区域内脂肪组织少于 5 毫米，且对利多卡因无过敏反应。在研究之前，测量区域至少已经 3 个月没有任何损伤、肿胀或感染。
我们将微透析探头插入右小腿皮肤下 0.5 厘米处。接下来，通过该区域进行 60 分钟的微透析，以使局部皮肤血流恢复到基线水平。然后，我们以 40 mA/min 的电流强度使用 2 mL 2%的利多卡因进行离子电渗。离子电渗在该区域进行 10.5 分钟，以收集利多卡因样本。在此阶段之后，电极再保留 50 分钟，总共 60 分钟。
药物样本通过化学系的反相高效液相色谱法（RP-HPLC）进行分析。
RP-HPLC 分析证实 10 名参与者的样本中均存在利多卡因。计算出在 5 毫米深度处检测到的利多卡因平均浓度为 3.63 mg/mL（超过输送浓度的 18%）。
当药物化合物含有肾上腺素且在主动输送结束后至少 50 分钟被动输送仍在进行时，我们发现 2%的利多卡因可以输送到皮肤表面以下 5 毫米处。
