A simple, sensitive HPLC-MS/MS method was developed and validated for the determination of lidocaine in skin and plasma of rats. The methods were established and validated assessing lower limit of quantitation (LLOQ), linearity, intra and inter-day precision and accuracy, selectivity, recovery and matrix effect. Chromatography was done on a Gemini column embedded with C18 stationary phase (50 mm x 2.0 mm, 5 µm particle size), using a gradient with mobile phases consisting of 0.1% HCOOH in bidistilled water and 0.1% HCOOH in acetonitrile. The mass spectrometer worked with electrospray ionization in positive ion mode and selected reaction monitoring, using target ions m/z 235.10 for lidocaine and m/z 245.10 for lidocaine-d10, used as internal standard.

Results

the linearity of the method was in the ranges of lidocaine concentrations 10.0-200.0 ng/mL for skin homogenate (accuracy 94.1-105.5%; R² ≥0.998) and 0.025–2 ng/mL for plasma (accuracy 96.2-104.8%; R² ≥0.996). The intra- and inter-day precision and accuracy determined on three quality control samples (20, 75 and 170 ng/mL for skin and 0.075, 0.4 and 1.5 ng/mL for plasma) were ≤ 4.2% and 103.8-108.2% for skin and ≤12.4% and 95.5-101.4% for plasma. The LLOQ was 10 ng/mL in skin homogenate and 0.025 ng/mL in plasma.

The applicability of the method was demonstrated by measuring lidocaine in skin and plasma after exposure to medicated patches containing 5% lidocaine.

中文翻译：

---

HPLC-MS / MS测定大鼠皮肤和血浆中的利多卡因。在研究从药膏中释放的应用

建立了一种简单，灵敏的HPLC-MS / MS方法，并验证了该方法可用于测定大鼠皮肤和血浆中的利多卡因。建立并验证了评估定量下限（LLOQ），线性，日内和日间精密度和准确性，选择性，回收率和基质效应的方法。色谱在装有C18固定相（50 mm x 2.0 mm，粒径5 µm）的Gemini色谱柱上进行，使用的梯度为流动相，该相由在蒸馏水中的0.1％HCOOH和在乙腈中的0.1％HCOOH组成。质谱仪以正离子模式进行电喷雾电离，并选择反应监测，使用利多卡因的目标离子m / z 235.10和利多卡因-d10的m / z 245.10作为内标。

结果

该方法的线性范围中的利多卡因浓度10.0-200.0毫微克/毫升为皮肤匀浆（精度94.1-105.5％; R的范围² ≥0.998）和血浆（精度96.2-104.8％0.025-2纳克/毫升; R ² ≥0.996）。在三个质量控制样品（皮肤分别为20、75和170 ng / mL，血浆为0.075、0.4和1.5 ng / mL）下确定的日内和日间精度和准确度分别为皮肤的≤4.2％和103.8-108.2％血浆≤12.4％和95.5-101.4％。皮肤匀浆中的LLOQ为10 ng / mL，血浆中的LLOQ为0.025 ng / mL。

该方法的适用性通过在暴露于含5％利多卡因的贴剂后测量皮肤和血浆中的利多卡因来证明。