Discovery and development of statins polar methane sulfonamide group, which is quite hydrophilic and confers low lipophilicity. The sulfonamide group forms a unique polar interaction with the enzyme. As a result, rosuvastatin has superior binding affinity to the HMGR enzyme compared to the other statins, which is directly related to its efficiency to lower LDL cholesterol. Lipophilicity of the statins is considered to be quite important since the hepatoselectivity of the statins is related to their lipophilicity. The more lipophilic statins tend to achieve higher levels of exposure in non-hepatic tissues, while the hydrophilic statins tend to be more hepatoselective. The difference in selectivity is
Specialty drugs in the United States were 10 specialty drugs on the market. According to the National Center for Biotechnology Information, by the mid-1990s, there were fewer than 30 specialty drugs on the market, but by 2008 that number had increased to 200. Specialty drugs may also be designated as orphan drugs or ultra-orphan drugs under the U. S. Orphan Drug Act of 1983. This was enacted to facilitate development of orphan drugs—drugs for rare diseases such as Huntington's disease, myoclonus, amyotrophic lateral sclerosis, Tourette syndrome and muscular dystrophy which affect small numbers of individuals residing in the United States. Not all specialty drugs are orphan