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Tablet hardness testing, is a laboratory technique used by the pharmaceutical industry to test the breaking point and structural integrity of a tablet "under conditions of storage, transportation, and handling before usage"〔 The breaking point of a tablet is based on its shape.〔(【引用サイトリンク】title=Tablet hardness testing )〕 It is similar to friability testing,〔 but they are not the same thing. Tablet hardness testers first appeared in the 1930s.〔(【引用サイトリンク】title=Some Information on Tablet Hardness Testing )〕 In the 1950s, the Strong-Cobb tester was introduced. It was patented by Robert Albrecht on July 21, 1953.〔 〕 and used an air pump. The tablet breaking force was based on arbitrary units referred to as Strong-Cobbs.〔 The new one gave readings that were inconsistent to those given by the older testers.〔 Later, electro-mechanical testing machines were introduced. They often include mechanisms like motor drives, and the ability to send measurements to a computer or printer.〔 There are 2 main processes to test tablet hardness: compression testing and 3 point bend testing. For compression testing, the analyst generally aligns the tablet in a repeatable way,〔 and the tablet is squeezed by 2 jaws. The first machines continually applied force with a spring and screw thread until the tablet started to break.〔 When the tablet fractured, the hardness was read with a sliding scale.〔 ==List of common hardness testers== There are several devices used to perform this task: *The Monsanto tester was developed 50 years ago. The design consists of "a barrel containing a compressible spring held between 2 plungers". The tablet is placed on the lower plunger, and the upper plunger is lowered onto it.〔(【引用サイトリンク】title=Quality control of solid dosage form )〕 *The Strong-Cobb tester forces an anvil against a stationary platform. Results are viewed from a hydraulic gauge.〔 The results are very similar to that of the Monsanto tester.〔 *The Pfizer tester compresses tablet between a holding anvil and a piston connected to a force-reading gauge when its plier-like handles are gripped.〔 *Erweka tester tests a tablet placed on the lower anvil and a weight moving along a rail transmits pressure slowly to the tablet.〔 *The Dr.Schleuniger Pharmatron tester operates in a horizontal position. An electric motor drives an anvil to compress a tablet at a constant rate. The tablet is pushed against a stationary anvil until it fractures. A reading is taken from a scale indicator.〔 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Tablet hardness testing」の詳細全文を読む スポンサード リンク
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