nearly completely absorbed from the upper part of the small intestine. Taking it together with food, including milk, has no relevant influence on resorption. It reaches highest blood plasma concentrations after one to two hours and has a plasma protein binding of 70–75%. 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.) Aknemin Solodyn (extended-release, for the treatment of acne) Dynacin Sebomin Mino-Tabs Acnamino Minopen (in Japan) Maracyn 2 (for treatment of bacterial infections in aquarium fish and amphibians) Quatrocin (in Syria) Minox (in Ireland) Minoz (in India and Romania) Divaine (in India) Vinocyclin 100 (100-mg dose approved for treatment of acne in Vietnam) Dentomycin (2% minocylcine gel for use in periodontal pockets) Amzeeq (4% foam, approved for treatment of acne United States) Zilxi (1.5% foam, approved for treatment of rosacea in the United States) Cleeravue-M Society and culture It is available as a generic medication. Research Early research has found a tentative benefit from minocycline in schizophrenia, with several trials underway. A 2014 meta-analysis found minocycline may reduce negative and total symptom scores and was well tolerated. Research is examining the possible neuroprotective and anti-inflammatory effects of minocycline against the