LC–MS/MS-ESI Method for Simultaneous Quantitation of Three Endocannabinoids and its Application to Rat Pharmacokinetic Studies

Abstract

An LC-MS/MS-ESI method has been validated for simultaneous estimation of the three endocannabinoids; N-arachidonoylethanolamine (AEA), N-oleoylethanolamine (OEA) and palmitoylethanolamide (PEA), in surrogate matrix using AEA-d (4) as an internal standard with highest sensitivity over the existing methods. Simple precipitation was used to extract analytes and these were subsequently analyzed on a monolithic column. Linear response function was established over the concentration range 12.3 to 1225 pg/ml for AEA (r > 0.994); 0.70 to 641 ng/ml for OEA (r > 0.999) and 0.54 to 321 ng/ml (r > 0.998) for PEA. The intra- and inter-day precision values met the acceptance to criteria as per US FDA guidelines. Analytes were found to be stable in the battery of stability studies. The method was applied to quantify endogenous levels of analytes in rat plasma.

Oral Ultramicronized Palmitoylethanolamide: Plasma and Tissue Levels and Spinal Anti-hyperalgesic Effect

“…In contrast, administration of naïve [ 13 C] 4 -PEA did not yield a significant peak plasma concentration of [ 13 C] 4 -PEA. Based on a basal value of around 9 pmol/ml PEA in rat plasma (Sharma et al, 2011 ; Wang et al, 2014 ), oral administration of PEA-um appears to rapidly elevate by some 50% circulating PEA levels. Vacondio et al ( 2015 ) orally administered to rats a formulation of PEA (100 mg/kg suspended in corn oil and subjected to ultrasonication/vortexing) that reached a peak, 20-fold rise in plasma concentration after 15 min followed by a return to baseline within 2 h. In terms of particle size their formulation would likely be more similar to PEA-um than to naïve PEA.…”

Chronic Oral Palmitoylethanolamide Administration Rescues Cognitive Deficit and Reduces Neuroinflammation, Oxidative Stress, and Glutamate Levels in A Transgenic Murine Model of Alzheimer’s Disease

“…Blood as well as hippocampus and prefrontal cortex (PFC) collected at sacrifice were immediately frozen in liquid nitrogen and stored at −80 • C for later PEA analysis. Plasma and tissue PEA levels were measured as described by Sharma et al [31] and Liput et al [32], respectively.…”

A sensitive LC‐MS/MS method for the study of exogenously administered 13C‐oleoylethanolamide in rat plasma and brain tissue

“…While analytical method validation data have not been presented to accompany any of the above-mentioned systemic OEA studies, a number of validated LC-MS or LC-MS/MS methods for OEA quantification in brain tissue [19][20][21][22] and plasma [23][24][25][26][27][28] (in combination with other NAEs) have been reported. The applications of these have been to measure endogenous concentrations in tissues [20][21][22][23][24] to study the physiology of OEA under normal and pathological conditions [25,28] or the pharmacology of agents that modulate endogenous concentrations (e.g., FAAH inhibitors) [19]. To validate methods in the presence of background endogenous OEA, a number of approaches have been used to produce calibration curves including background subtraction [19,20,22,23,25], neat solutions [21,26,28], and stripped matrices [27].…”

“…The applications of these have been to measure endogenous concentrations in tissues [20][21][22][23][24] to study the physiology of OEA under normal and pathological conditions [25,28] or the pharmacology of agents that modulate endogenous concentrations (e.g., FAAH inhibitors) [19]. To validate methods in the presence of background endogenous OEA, a number of approaches have been used to produce calibration curves including background subtraction [19,20,22,23,25], neat solutions [21,26,28], and stripped matrices [27]. However, each of these methods for validation has drawbacks such as unpredictable variation in background signal and an inability to account for ion suppression/enhancement and varying extraction efficiency, which can make quantification in samples unreliable [29].…”