Different calcium channels are present in vascular tissue and cardiac tissue; an in vitro study on human vascular and cardiac tissues comparing how selective various calcium channel blockers are for vascular compared to cardiac tissue found the following vascular/cardiac tissue ratios: mibefradil 41, felodipine 12; nifedipine 7, amlodipine 5, and verapamil 0.2.[6]: 172
Chemistry
Felodipine is a member of the 1,4-dihydropyridine class of calcium channel blockers.[6]: 20–21 It is a racemic mixture, and is insoluble in water but is soluble in dichloromethane and ethanol.[6]: 25
History
The Swedish company Hässle, a division of Astra AB, discovered felodipine;[7] it filed a patent application in 1979 claiming felodipine as an antihypertensive drug.[8][9] Astra partnered this drug and others with Merck & Co. in the US under a 1982 agreement between the companies.[7] The drug was approved by the FDA in 1991 after a three-and-a-half-year review; the drug entered a very crowded market to included the other calcium channel blockers nifedipine, verapamil, nicardipine, and isradipine.[7] The FDA gave the drug a 1C rating, meaning that it found little difference between felodipine and the drugs already approved for the same use.[7]
In 1994 Astra AB and Merck changed their partnership to a joint venture called Astra Merck,[10] and in 1998 Astra (by that time, AstraZeneca) bought out Merck's rights in the joint venture.[11]
The first generics became available in Sweden in 2003[12] and in the US in 2004.[13]: 155
In April 2016, AstraZeneca announced that they were selling the right to market felodipine in China to China Medical System Holdings for $310 million; AZ would continue to manufacture the drug.[14]
^ abcJoshi GS, Burnett JC, Abraham DJ (2003). "Cardiac Drugs: Antianginal, Vasodilators, Antiarrhythmic". In Abraham DJ (ed.). Burger's medicinal chemistry and drug discovery. Volume 3: Cardiovascular Agents and Endocrines (6th ed.). Hoboken, N.J.: Wiley. ISBN9780471270904.
^Astrazeneca AB v. Mutual Pharmaceutical Co. (United States Court of Appeals for the Federal Circuit 2004), Text.
^US patent 4,264,611, Berntsson P, Carlsson S, Gaarder J, Ljung B, "2,6-Dimethyl-4-2,3-Disubstituted Phenyl-1,4-Dihydro-Pyridine-3,5 Dicarboxylic Acid-3,5-Asymmetric Diesters having Hypotensive Properties, as well as Method for Treating Hypertensive Conditions and Pharmaceutical Preparations Containing Same", issued 28 April 1981, assigned to Aktiebolaget Hassle
^George J (28 July 1997). "Secret of Astra Merck". Philadelphia Business Journal. Philadelphia. Retrieved 7 November 2016.
^Jönsson B (2008). "Sweden". In Rapoport J, Jacobs P, Jonsson E (eds.). Cost Containment and Efficiency in National Health Systems a Global Comparison. Weinheim: Wiley-VCH. p. 218. ISBN9783527622955.