Validation of a bioanalytical method using capillary microsampling of 8 μl plasma samples: application to a toxicokinetic study in mice

Background: Capillary microsampling was recently introduced as a new technique for simplified collection and handling of small, exact volumes of liquid matrices. In this article, a bioanalytical method was developed and fully validated for 8 mu l plasma samples and applied to a toxicology study in mice. Results: The method was validated in the concentration range 0.06-30 mu M. A procedure where 32 mu l of blood was collected for preparation of 8 mu l plasma was successfully implemented at the animal facility. All the results for the method and study validation met the requirements of a regulated assay. Conclusion: It is shown that 8 mu l plasma microsamples can be sampled and analyzed with consistently excellent accuracy and precision. Capillary microsampling of plasma offers a possibility to combine ethical, scientific and economic benefits while still maintaining the advantage of having drug exposure data in plasma.