Evaluation of dried blood spot technique for pharmacokinetic study of hydrochlorothiazide and comparison of human plasma versus dried blood spot

Abstract

Background: The dried blood spot (DBS) technique is a convenient alternative sample collection method to venipuncture. The use of DBS was fi rst widely introduced in the 1960's by Dr. Guthrie to measure levels of phenylalanine in newborns for the diagnosis of phenylketonuria. The scientifi c community has recently expressed interest in applying the DBS technique for quantifi cation of drugs in biological fl uids. Materials and Methods: Reversed phase high performance liquid chromatography-tandem mass spectrometry (LC-MS/MS) assays for the determination of hydrochlorothiazide (HCTZ) in human plasma and DBS samples were developed and validated. Furthermore, clinical samples collected from human volunteers as a part of pharmacokinetic (PK) study and PK data from plasma were compared against DBS. Results: The range of reliable response in plasma and DBS was 2-200 ng/mL with a correlation coeffi cient ≥0.997. Inter-day accuracy was always within 85-115%, and inter-day precision for plasma and DBS were <15%. Conclusions: Comparison of HCTZ PK data in DBS and plasma yielded good correlation, indicating that DBS can be used as a plasma alternative for PK analyses in vivo.

Therapeutic drug monitoring in India: A strength, weakness, opportunity and threats analysis

“…The proof of concept for this application has been provided by Das et al ., where carbamazepine from dried blood spot assay was demonstrated to be comparable to liquid blood assay quantified by the liquid chromatographic method in a distant laboratory in a tertiary care hospital 113 . There is evidence of available expertise in the country for developing bioanalytical methods 108,112,114‐119 . Still, it needs a goal‐oriented, organized effort to standardize as many drugs as possible to make TDM available even in the remote parts of the country.…”

“…113 There is evidence of available expertise in the country for developing bioanalytical methods. 108,112,[114][115][116][117][118][119] Still, it needs a goal-oriented, organized effort to standardize as many drugs as possible to make TDM available even in the remote parts of the country. This would reduce the cost of establishing multiple TDM facilities and save the cost related to travel, loss of wages etc.…”