The substance penetrates into almost all tissues; very high concentrations are found in the gallbladder and liver. It crosses the blood–brain barrier better than doxycycline and other tetracyclines, reaching therapeutically relevant concentrations in the cerebrospinal fluid and also in inflamed meninges.Minocycline is inactivated by metabolization in the liver to about 50%. The rest is predominantly excreted into the gut (in part via the gallbladder, in part directly from blood vessels) and eliminated via the feces. About 10–15% are eliminated via the kidneys. The biological half-life is 14–22 (11–26) hours in healthy people, up to 30 hours in those with kidney failure, and significantly longer in those with liver disease. Chemistry
The drug is used in form of minocycline hydrochloride dihydrate, which is sparingly soluble in water and slightly soluble in ethanol. Minocycline reacts acidic in aqueous solution. History
Minocycline was patented in 1961 and came into commercial use in 1971. A topical foam for treatment of acne was approved in 2019. Society and culture
Trade names
Many forms of minocycline are no longer covered by patent, so it is marketed under a variety of trade names:

Minomycin
Minostad (in Europe, for the treatment of acne)
Akamin
Minocin
Minoderm
Cyclimycin
Arestin (1-mg doses administered locally into periodontal pockets, after scaling and root planing, for treatment of periodontal disease.)
Icosahedral symmetry 
  
    
      
        
          
            I
          
          
            h
          
        
      
    
    {\displaystyle \mathrm {I} _{h}}
   is isomorphic to the alternating group on 5 letters 
  
    
      
        
          
            A
          
          
            5
          
        
      
    
    {\displaystyle \mathrm {A} _{5}}
   of order 120, realized by actions on these uniform polyhedron compounds.