title: 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: BACKGROUND
  Testosterone (T) and nandrolone (N) esters require deep im injections by medical personnel but these often deposit injectate into sc fat so that more convenient sc self-administration may be feasible.
  
  
  OBJECTIVE
  To investigate the feasibility and pharmacology of sc injection of N decanoate in healthy men using dried blood spot (DBS) for frequent blood sampling without clinic visits.
  
  
  METHODS
  Healthy male volunteers received 100 mg N decanoate by a single sc injection. Finger-prick capillary blood was spotted onto filter paper before injection daily at home for 21 d and stored at room temperature. Venous whole blood was also spotted onto filter paper before and weekly for 3 wk after injection. DBS were extracted for assay of N and T by liquid chromatography tandem mass spectrometry in a single batch with serum concentrations estimated with adjustment for capillary blood sample volume and hematocrit to define peak (N) or nadir (T) time and concentration from individual daily measurements.
  
  
  RESULTS
  Daily serum N peaked 2.50 ± 0.25 (SEM) ng/mL at a median (range) of 6 (4-13) days causing a reduction in serum T from 3.50 ± 0.57 ng/mL at baseline to a nadir of 0.38 ± 0.13 (SEM) ng/mL (89 ± 3% suppression) at a median (range) of 8 (5-16) days. Simultaneously sampled capillary, venous whole blood, and serum gave almost identical results for serum T and N. Finger-pricks and sc injections were well tolerated.
  
  
  CONCLUSIONS
  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.
authors.affiliation: Andrology Department (G.K.S.S., L.T., M.J., D.J.H.), Concord Hospital, Sydney, New South Wales 2139, Australia; Faculty of Pharmacy (G.K.S.S.), Universiti Teknologi MARA, Bandar Puncak Alam, Selangor, 42300 Malaysia; and ANZAC Research Institute (G.K.S.S., R.D., M.J., D.J.H.), University of Sydney, Sydney New South Wales 2139, Australia.
authors.forename: Gurmeet K S
authors.initials: GK
authors.lastname: Singh
authors.forename: Leo
authors.initials: L
authors.lastname: Turner
authors.forename: Reena
authors.initials: R
authors.lastname: Desai
authors.forename: Mark
authors.initials: M
authors.lastname: Jimenez
authors.forename: David J
authors.initials: DJ
authors.lastname: Handelsman
mesh_terms: D000328:Adult; D001800:Blood Specimen Collection / Q000379:methods; D002853:Chromatography, Liquid / Q000379:methods; D003692:Delayed-Action Preparations / Q000008:administration & dosage / Q000493:pharmacokinetics*; D059788:Dried Blood Spot Testing / Q000379:methods*; D005640:Follicle Stimulating Hormone / Q000097:blood; D006801:Humans; D007279:Injections, Subcutaneous; D007986:Luteinizing Hormone / Q000097:blood; D008297:Male; D009277:Nandrolone / Q000008:administration & dosage / Q000031:analogs & derivatives* / Q000097:blood / Q000493:pharmacokinetics; D000077603:Nandrolone Decanoate; D053719:Tandem Mass Spectrometry / Q000379:methods*; D013739:Testosterone / Q000097:blood; D055815:Young Adult
chemical_list: D003692:Delayed-Action Preparations; D013739:Testosterone; D009277:Nandrolone; D007986:Luteinizing Hormone; D005640:Follicle Stimulating Hormone; D000077603:Nandrolone Decanoate