A resealable cap ( 110, 210 ) for a medicament vial ( 114, 214 ) has a base portion ( 112, 212 ) formed of vulcanized rubber or like material known for providing a stable environment for the medicament contained within the vial, and a resealable portion ( 126, 226 ) overlying the base portion. The resealable portion ( 126, 226 ) is made of low-density polyethylene or like material, and can be punctured by a needle or like injection member ( 140, 282 ) for dispensing medicament into the vial ( 114, 214 ). Prior to filling, the cap ( 110, 210 ) is assembled to the vial ( 114, 214 ) and the cap/vial assembly is sterilized. Then, a needle ( 140, 282 ) is inserted through the cap ( 110, 210 ) and medicament is introduced through the needle and into the vial. Upon withdrawal of the needle ( 140, 282 ), the penetrated region of the cap ( 248 ) is fused by laser ( 276 ) or direct heat sealing ( 264 ) to hermetically seal the needle hole ( 294 ) in the cap.
