A fractional lobe processor comprises a barrel with heating and cooling means having two parallel intersecting bores of equal diameter, wherein the centre distance between the two bores is lesser than the diameter of the bore; a shaft coupled with a plurality of screw elements to form a screw within each bore, wherein the screws are intermeshing and form at least three zones within the barrel, the zones comprising an intake zone comprising at least one deep flighted shovel element on each intermeshing screw for receiving a feed comprising an active substance and/or an excipient, a melt zone consisting of only fractional lobe elements for melting the active substance and/or an excipient to form a viscous mass or melt, and a discharge zone, wherein the melt zone is located before the discharge zone and after the intake zone; and wherein the melt zone has a plurality of fractional lobe elements on each shaft.