title: Validation of a dried blood spot LC-MS/MS approach for cyclosporin A in cat blood: comparison with a classical sample preparation.
abstract: A rapid, selective and sensitive bioanalytical method was developed and validated for cyclosporin A (CsA) in cat blood samples using dried blood spot (DBS) coupled with high pressure liquid chromatography hyphenated to positive electrospray tandem mass spectrometry (HPLC-ESI-MS/MS). CsA was quantified using a structural analog cyclosporin D (CsD) as internal standard in multiple reaction monitoring mode (MRM) using the transitions 1220→1203 for CsA and 1234→1217 for CsD. A 5-μL blood aliquot was spotted onto a DBS card, then after a drying step, blood spots were punched out from the cards and extracted with MeOH before injection into a LC-MS/MS system. The linear range of the method was 5-2000 ng/mL, with accuracy and precision within the FDA acceptance criteria (i.e., ±15% and ±20% for the lowest level). In the study presented herein a comparison was made between this new methodology, based on the use of DBS, and a previously developed solid phase extraction (SPE) procedure, applied to blood samples from a cat pharmacokinetic study. Good correlation (r(2)=0.97) was demonstrated between the data obtained with the two methods. The DBS methodology revealed to be cheaper, faster, less solvent-consuming and requiring less blood volume from animals than the previous SPE method. Thus, the proposed HPLC-ESI-MS/MS method, based on DBS, has demonstrated to be a suitable and advantageous approach for the analysis of CsA in cat blood.
authors.affiliation: Novartis Animal Health, Novartis centre de Recherche Santé Animale SA, CH-1566 Saint Aubin, Switzerland. rayane.mohamed@novartis.com
authors.forename: Rayane
authors.initials: R
authors.lastname: Mohamed
authors.forename: Laura
authors.initials: L
authors.lastname: Mercolini
authors.forename: Suzanne
authors.initials: S
authors.lastname: Cuennet-Cosandey
authors.forename: Jacques
authors.initials: J
authors.lastname: Chavent
authors.forename: Maria Augusta
authors.initials: MA
authors.lastname: Raggi
authors.forename: Mathieu
authors.initials: M
authors.lastname: Peyrou
mesh_terms: D000818:Animals; D002415:Cats; D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D016572:Cyclosporine / Q000097:blood*; D059788:Dried Blood Spot Testing / Q000191:economics / Q000379:methods*; D007166:Immunosuppressive Agents / Q000097:blood; D057230:Limit of Detection; D015203:Reproducibility of Results; D052616:Solid Phase Extraction / Q000379:methods; D012997:Solvents / Q000737:chemistry; D013048:Specimen Handling / Q000191:economics / Q000379:methods; D021241:Spectrometry, Mass, Electrospray Ionization / Q000379:methods; D053719:Tandem Mass Spectrometry / Q000379:methods*; D013997:Time Factors
chemical_list: D007166:Immunosuppressive Agents; D012997:Solvents; D016572:Cyclosporine