title: A novel finasteride 0.25% topical solution for androgenetic alopecia: pharmacokinetics and effects on plasma androgen levels in healthy male volunteers.
abstract: OBJECTIVE
  Finasteride, a selective inhibitor of type 2 5-α reductase isoenzyme, inhibits the conversion of testosterone to dihydrotestosterone (DHT) and is indicated in the treatment of male androgenetic alopecia. The study objective was to evaluate a newly developed finasteride 0.25% topical solution in comparison to the marketed finasteride 1 mg tablet, with respect to finasteride pharmacokinetics and suppressive effects on plasma DHT.
  
  
  METHODS
  24 healthy men with androgenetic alopecia were randomized in a single center, open-label, parallel-group, exploratory study, and received either multiple scalp applications of the topical solution b.i.d. or oral doses of the reference tablet o.d. for 7 days. Plasma finasteride, testosterone and DHT concentrations were determined.
  
  
  RESULTS
  After multiple doses, mean (± SD) finasteride C(max) and AUC(0-t) corresponded to 0.46 ± 0.28 ng/mL and 6.64 ± 7.50 ng/mL x h for the topical solution and to 6.86 ± 1.78 ng/mL and 57.93 ± 29.38 ng/mL x h for the tablet. Plasma DHT was reduced by ~ 68 - 75% with the topical solution and by ~ 62 - 72% with the tablet. No relevant changes occurred for plasma testosterone with either treatment. No clinically significant adverse events occurred.
  
  
  CONCLUSIONS
  A strong and similar inhibition of plasma DHT was found after 1 week of treatment with the topical and tablet finasteride ormulations, albeit finasteride plasma exposure was significantly lower with the topical than with the oral product (p < 0.0001).
authors: Maurizio
authors: M
authors: Caserini
authors: Milko
authors: M
authors: Radicioni
authors: Chiara
authors: C
authors: Leuratti
authors: Ottavia
authors: O
authors: Annoni
authors: Renata
authors: R
authors: Palmieri
mesh_terms: D000287:Administration, Topical; D000328:Adult; D000505:Alopecia / Q000188:drug therapy*; D013196:Dihydrotestosterone / Q000097:blood*; D018120:Finasteride / Q000008:administration & dosage* / Q000493:pharmacokinetics; D064368:Healthy Volunteers; D006801:Humans; D008297:Male; D008875:Middle Aged
chemical_list: D013196:Dihydrotestosterone; D018120:Finasteride