Full validation of curcumin analytical method by LC-MS/MS points out that the degree of hemolysis in plasma affects the quantitation: application in dog plasma study

Curcumin has gained great attention in the last decades due to its fascinating properties for humans, such as anti-inflammatory or as cytotoxic against cancer. These effects are also claimed for pets such as cats and dogs, where curcumin administration is a daily practice routine. However, curcumin presents poor oral bioavailability, driving scientists to look for new delivery systems. In the last decades, several analytical methods for the quantification of curcumin in plasma have been published. To our knowledge there are no published reports on the effect of the level of hemolysis in the determination of this compound. In the present paper, a highly specific, sensitive and selective method is presented using Molecular Reaction Monitoring (SRM) using positive ionization (ESI+) mode. Curcumin and clopidogrel bisulfate – used as internal standard (IS) – were separated on an Acquity UPLC BECH Shield RP 18 column (1.7µm, 2.1 X 100mm) with 0.1% formic acid in acetonitrile and water in proportion of 60:40 (v/v). The analyte transitions were 369.3→177.06 m/z for curcumin and 322→212.05 m/z for IS. The method was fully validated and showed good linearity (R2 ≥ 0.999) over the range of 3-160 ng/mL. The Relative Standard Deviation (RSD) were less than 6% for intra-and inter-day analysis and recovery spanned 85-95%. We proved that the degree of hemolysis impaired curcumin quantitation. This method was applied to test curcumin bioavailability in both a mucoadhesive nanocapsule formulation and traditional capsules in dogs that attended routine veterinary consultation.Resumen. La curcumina ha ganado gran atención en las últimas décadas debido a sus propiedades terapéuticas para los humanos, como antiinflamatorio o citotóxico contra el cáncer. Estos efectos también se observan en pequeñas especies como gatos y perros, donde la administración de curcumina se ha vuelto una alternativa. Sin embargo, la curcumina presenta una baja biodisponibilidad oral, lo que impulsa a los científicos a buscar nuevos sistemas de administración. En las últimas décadas, se han publicado varios métodos analíticos para la cuantificación de curcumina en plasma. Actualmente, no hay informes publicados sobre el efecto del grado de hemólisis en la determinación de este compuesto. En este trabajo se desarrolló un método específico, sensible y selectivo utilizando el Monitoreo de reacción seleccionado (SRM) en modo de ionización positiva (ESI +). La curcumina y el bisulfato de clopidogrel, utiliza