Drug manufacture. Pill strength being tested by the manufacturers. Only a small part of a drug pill is the actual drug, and most of it is an inert base material that delivers the medicine to the patient's stomach. This material needs to be tested to see if it has the correct properties and is not too hard or too soft. This test uses a vice, which is being tightened until the pill disintegrates. This drug has been manufactured by the pharmaceutical company Merck Sharp and Donne (MSD). The 516 product code indicates that this is a 500mg tablet of Aldomet (methyldopa), a drug for treating high blood pressure (hypertension).