Assay preparation-Weigh and finely powder not fewer than 20 tablet.
Transfer an accurately weighed portion of the powder,equivalent to sbout 100 mg of Acetaminophen,to a 200 ml volumetric flask, add about 100 ml of Mobile phase, shake by mechanical means for 10 minutes,sonicate for about 5 minutes,dilute with Mobile phase to volume,and mix.
Transfer 5.0 ml of this solution to a 250 ml volumetric flask, dilute with Mobile phase to volume,and mix.Pass a portion of this solution through a filter having a 0.5 -um or finer porosity, discarding the first 10 mL of the filtrate.
Use the clear filtrate as the Assay preparation.