Process for preparing a lyophilized material

A process for lyophilizing a substance present in a carrier liquid comprising:

• providing a container closed by a closure made of elastomeric material having an elasticity, said elastomeric material having a penetrable region with a previously-formed puncture hole which is closed at a rest stage of the closure;
• providing a penetrator having an engaging end;
• moving the penetrator from a first position where the penetrator contacts said material at said previously-formed puncture hole to a second position so that during the movement its engaging end opens said previously-formed puncture hole so as to form an opening communication passage;
• stopping the movement of the penetrator at the second position so that its engaging end stops just before entering into the material of the closure and maintaining the penetrator in said second position by applying a compensating force in order to compensate for the elasticity of said elastomeric material;
• evaporating the carrier liquid of the substance from the container via the opening communication passage by maintaining the substance in the carrier liquid at a temperature such that the carrier liquid is frozen, and by applying reduced pressure so that the frozen liquid sublimates directly from the solid to the vapor state;
• and
• releasing said compensating force applied on the penetrator and withdrawing the penetrator from the elastomeric penetrable region.