Bioorg Med Chem Lett. 2009 Oct 29.
Thyroid receptor agonists for the treatment of androgenetic alopecia.
Li JJ, Mitchell LH, Dow RL.
Department of Chemistry, Michigan Laboratories, Pfizer Global Research & Development, 2800 Plymouth Road, Ann Arbor, MI 48105, United States.
A thyroid hormone receptor beta subtype-selective thyromimetic 5 was found to be efficacious in both mouse and monkey hair growth models after topical applications. It penetrates the skin according to the test in human cadaver skin mounted onto Franz diffusion chambers. The serum drug level of 5 is below the limit of quantification during tests in the bald stump-tailed macaques (Macaca arctoides). It is tested negative in the 3T3 neutral red uptake (NRU) phototoxicity test, indicating a low risk for causing photo-irritation. It is also rapidly metabolized according to the PK data, thus the systemic exposure is limited.
One of the most important things about this study is that it was tested in monkey hair growth cause is very similar ( a lot more similar than mouse hair biology ) . Finasteride , Dutasteride , minoxidil , all where tested and effective in Monkeys before it was in clinical trials for humans .
Previous research has indicated that Thyroid Receptor Agonists such as thyroxine and topical triiodo-thyronine have potential for stimulating anagen prolongation and hair matrix keratinocyte proliferation. But There is known cardiotoxicity from taking these drugs though, so the researchers where looking for analogs of TRA’s with short-half life and quick systematic clearance and they finally create it .
