Pipette with encapsulated or integral filter, and method and apparatus for forming same

Measuring pipettes including integral or encapsulated filters, as well as methods and apparatuses for forming the same, are provided. A filter material (e.g., a discrete element in solid form) or a filter material precursor (e.g., a foamable thermoplastic composition and a blowing agent) to be introduced into a hollow interior of a softened thermoplastic material present within a mold during pipette fabrication. A pipette includes a filter element comprising foamed polymeric material within a mouthpiece region, wherein an outer portion of the filter element is bound to or encapsulated in an inner wall of the mouthpiece region. A filter material precursor may be supplied coaxially with a tubular flow of thermoplastic material into the mold, may be supplied laterally through a mold wall, or may be injected into a molten thermoplastic pipette forming material upstream of an extruder outlet.