The use of a membrane filtration device to form dried plasma spots for the quantitative determination of guanfacine in whole blood

Abstract

The described work demonstrates proof-of-principle using membrane sample preparation techniques to form DPS samples from whole blood for subsequent bioanalysis by LC/MS/MS. This approach has the potential to eliminate the hematocrit issues from the current controversy surrounding validation of DBS assays.

Dried Blood Spots - Preparing and Processing for Use in Immunoassays and in Molecular Techniques

“…Given these data, it can be virtually excluded that any of the discrepancies observed when testing coupled serum/DBS pairs for markers of HBV, HCV and HIV infections 17 was caused by the choice of the filter card alone. However, when accurate quantification of an analyte is indispensable, source-to-source variation may no longer be negligible and more sophisticated techniques, e.g., perforated DBS (PDBS) as a method for microsampling 30 or the preparation of dried serum spots (DSS) 31 may have to be applied instead of conventional DBS testing 10 .…”

A validated method for the quantification of fosfomycin on dried plasma spots by HPLC–MS/MS: Application to a pilot pharmacokinetic study in humans

“…The use of membrane filtration devices to directly form dried plasma spot samples may offer a simplification to preparation [16,34] and with this the dried plasma spot sampling techniques may offer more of the benefits currently available with dried blood spots -smaller sample volumes from thumb or needle-prick, no pre-treatment prior to shipment -without the inherent challenges of samples containing hematocrit.…”

“…Quantification of drugs using the dried plasma spot sampling technique has been described for daptomycin [10], valproic acid and gabapentin [11,12], linezolid [13], paroxetine [14], acetaminophen [15], guanfacine [16], iothalamate [17], vigabatrin [18], triazoles [19], and antiepileptic drugs [20], as well as anti-HIV drugs [21].…”

Direct Analysis of Dried Blood Spot Samples

“…For example, a centrifuge is required to produce plasma from whole blood, and more importantly in terms of microsampling, around half the sample taken from the patient, volunteer or animal, is wasted. A solution to the need for centrifugation could come from membrane filtration devices which produce a DPS following addition of whole blood (65,64) . It has also been demonstrated that natural variance in albumin concentrations can vary the diameter of plasma spots in much the same way to what is observed with blood and HCT (Spooner et al, GSK, unpublished).…”

“…The requirement for accurate volume blood dispensing clearly compromises the simplicity of the original workflow that was envisioned for DBS, but the potential combined ethical, financial and logistic advantages on offer from DBS sampling still far outweigh the extra complexity and cost associated with an accurate volume DBS workflow, if practical accurate volume collection methods can be utilised (23,59) . In the last few years, new technology and whole blood dispensing techniques have been reported that potentially make accurate volume spotting, and whole-spot sample extraction options a realistic proposition (84,85,86,61,64,65,63) . New blood collection technologies such as the DBS-System (from Déglon et al), and Mitra or volumeric absorptive microsampling (VAMS) (from Phenomenex, albeit in a different format to card based DBS) demonstrate that practical, and cost effective solutions to accurate volume blood microsampling are available (63,130) .…”