CEFALEXIN CONTAINS NOT LESS THAN 95.0 PER CENT AND NOT MORE THAN;THE EQUIVALENT OF 102.0 PER CENT OF (6R, 7R)-7-﹝(R)-2-AMINO-2-;PHENYLACETAMIDO﹞-3-METHYL-8-OXO-5-THIA-1-AZABICYCLO﹝4.2.0﹞OCT-2;-ENE-2-CARBOXYLIC ACID, CALCULATED WITH REFERENCE TO THE ANHYDROUS;SUBSTANCE.