Finasteride-d9 is intended for use as an internal standard for the quantification of finasteride by GC- or LC-MS. Finasteride is a 4-azasteroid competitive inhibitor of 5α-reductase type II (IC50 = 4.2 nM) and a derivative of testosterone.1 It is 100-fold selective for 5α-reductase type II over type I. Finasteride (10 µM) does not affect the growth of androgen-refractory PC3 prostate cancer cells but increases the protein levels of Nrf2 and heme oxygenase-1 (HO-1).2 It decreases prostatic diameter and volume, as well as dihydrotestosterone, but not testosterone, serum levels in dogs with spontaneous benign prostatic hypertrophy when administered at doses of 0.1 and 0.5 mg/kg.3 Finasteride reduces testosterone-induced type I procollagen and TGF-β1 protein levels in cultured human scalp dermal fibroblasts in a model of androgenic alopecia when applied at a concentration of 0.1 μM.4 Formulations containing finasteride have been used in the treatment of benign prostatic hyperplasia and androgenic alopecia in men.
1.Flores, E., Bratoeff, E., Cabeza, M., et al.Steroid 5α-reductase inhibitorsMini Rev. Med. Chem.3(3)225-237(2003) 2.Yun, D.-K., Lee, J., and Keum, Y.-S.Finasteride increases the expression of hemoxygenase-1 (HO-1) and NF-E2-related factor-2 (Nrf2) proteins in PC-3 cells: Implication of finasteride-mediated high-grade prostate tumor occurenceBiomol. Ther. (Seoul)21(1)49-53(2013) 3.Sirinarumitr, K., Johnston, S.D., Kustritz, M.V.R., et al.Effects of finasteride on size of the prostate gland and semen quality in dogs with benign prostatic hypertrophyJ. Am. Vet. Med. Assoc.218(8)1275-1280(2001) 4.Yoo, H.G., Kim, J.S., Lee, S.R., et al.Perifollicular fibrosis: Pathogenetic role in androgenetic alopeciaBiol. Pharm. Bull.29(6)1246-1250(2006)