Pharmacokinetic-Pharmacodynamic Study of Subcutaneous Injection of Depot Nandrolone Decanoate Using Dried Blood Spots Sampling Coupled With Ultrapressure Liquid Chromatography Tandem Mass Spectrometry Assays

Abstract

This study demonstrates that A) DBS sampling with liquid chromatography mass spectrometry steroid analysis achieves frequent time sampling in the community without requiring clinic visits, venesection, or frozen serum storage, and B) androgen esters in an oil vehicle can be delivered effectively by sc injection, thus avoiding the need for medically supervised deep-im injections.

Pharmacokinetics of testosterone cream applied to scrotal skin

“…The nandrolone dosage was selected as known to transiently suppress endogenous testosterone for the study period without adverse effects (Minto et al, 1997;Handelsman et al, 2009Handelsman et al, , 2014Singh et al, 2014). The secondary endpoints were serum dihydrotestosterone (DHT) and estradiol (LC-MS) as well as tolerability.…”

“…They were administered two intramuscular injections of nandrolone decanoate (50 mg in 1 mL arachis oil vehicle) comprising 200 mg three days prior to and 100 mg four days after the first testosterone dose to suppress endogenous testosterone secretion throughout the study. The nandrolone dosage was selected as known to transiently suppress endogenous testosterone for the study period without adverse effects (Minto et al, 1997;Handelsman et al, 2009Handelsman et al, , 2014Singh et al, 2014). Each eligible, consenting participant was administered three single doses of testosterone cream in random sequence on different study days with at least 2 days wash-out period between studies.…”

“…Serum testosterone, DHT, and estradiol were measured in solvent extracts (methyl tert-butyl ether) by liquid chromatography, tandem mass spectrometry as described in detail elsewhere (Harwood & Handelsman, 2009;Singh et al, 2014) in the Andrology laboratory, ANZAC Research Institute. Dried blood spots were extracted for concurrent measurement of testosterone and nandrolone as described (Singh et al, 2014).…”

“…Serum testosterone, DHT, and estradiol were measured in solvent extracts (methyl tert-butyl ether) by liquid chromatography, tandem mass spectrometry as described in detail elsewhere (Harwood & Handelsman, 2009;Singh et al, 2014) in the Andrology laboratory, ANZAC Research Institute. Dried blood spots were extracted for concurrent measurement of testosterone and nandrolone as described (Singh et al, 2014). The limits of detection and coefficients of variation (range for three quality control samples run in triplicate in each run) were 10 pg/mL (35 pM) and 3-6% for testosterone, 50 pg/mL (173 pM) and 9-11% for DHT and 1 pg/mL (4 pM) and 7-13% for estradiol.…”

LC–MS/MS bioanalysis of loratadine (Claritin) in dried blood spot (DBS) samples collected by subjects in a clinical research study

“…Furthermore, DBS samples can be promptly and conveniently taken as needed and, after a 2-3 hour drying period, be directly sent to a laboratory for analysis. This feature of DBS sampling opens up possibilities of (1) collecting clinical blood (e.g., PK) samples from patients in remote or developing regions in resource-limited settings (e.g., lack of the basic equipment such as centrifuge, freezer, etc., that are needed for conventional PK blood/plasma/serum sampling) for various clinical testing [2][3][4][5][6][7][8], and (2) permitting flexible or frequent blood sample collection in a point-of-care setting (e.g., in community or at home with no need of visiting clinic) for disease surveillance (e.g., HIV, HBV, HCV) or therapeutic drug monitoring [9][10][11][12][13][14][15][16][17]. In therapeutic drug monitoring, the most challenging part is the accuracy of sample collection timing as drugs are commonly monitored at trough.…”