By so doing it induces cell differentiation and apoptosis and prevents the development of drug resistance. It also has anti-angiogenic effects and inhibits cancer metastasis. The retinoic acid receptors (RARs) regulate cell differentiation and proliferation whereas RXRs regulate apoptosis. Physical properties
Bexarotene is a solid, white powder. It is poorly soluble in water; the solubility is estimated to be about 10-50 μM. It is soluble in DMSO at 65 mg/mL and in ethanol at 10 mg/mL with warming. History
SRI International and the La Jolla Cancer Research Foundation (now the Sanford-Burnham Medical Research Institute) collaborated on work that resulted in patent filings for the drug.The developer of bexarotene (brand name Targretin) was Ligand Pharmaceuticals, a San Diego biotech company which received FDA approval for the drug in 1999. The FDA approved bexarotene on 29 December 1999.Japanese pharmaceutical Eisai bought the rights to Targretin and three other anti-cancer products from Ligand in 2006. In the United States, patents on the drug expired in 2016.It received EMA approval on 29 March 2001.Early-stage preclinical studies suggested that bexarotene reduced amyloid plaques and improved mental functioning in a small sample of mice engineered to exhibit Alzheimers-like symptoms   although subsequent studies have yielded mixed results.The results of CCMR-One, a clinical trial of the effects of bexarotene on patients with multiple sclerosis operated by the University of Cambridge, have shown that the drug can cause remyelination, but will not lead to the drug being used as a therapy, due to its risk profile. References
External links
"Bexarotene". Drug Information Portal.
Finasteride does not completely suppress DHT production because it lacks significant inhibitory effects on the 5α-reductase type I isoenzyme, with more than 100-fold less inhibitory potency for type I as compared to type II (IC50 = 313 nM and 11 nM, respectively). This is in contrast to inhibitors of all three isoenzymes of 5α-reductase like dutasteride, which can reduce DHT levels in the entire body by more than 99%. In addition to inhibiting 5α-reductase, finasteride has also been found to competitively inhibit 5β-reductase (AKR1D1). However, its affinity for the enzyme is substantially less than for 5α-reductase (an order of magnitude less than for 5α-reductase type I) and hence is unlikely to be of clinical significance.As of 2012, the tissues in which the different isozymes of 5α-reductase are expressed are not fully clear. This is because different investigators have obtained varying results with different reagents, methods, and tissues examined. However, the different isozymes of 5α-reductase appear to be widely expressed, with notable tissues including the prostate gland, seminal vesicles, testes, epididymides, skin, hair follicles, liver, kidneys, and brain, among others.By inhibiting 5α-reductase and thus preventing DHT production, finasteride reduces androgen signaling in tissues like the prostate gland and the scalp. In the prostate, this reduces prostate volume, which improves BPH and reduces risk of prostate cancer. Finasteride reduces prostate volume by 20 to 30% in men with benign prostatic hyperplasia.