ExxcoreTM DVA resins are blends of a polyamide (PA) with dynamically vulcanized, brominated poly (isobutylene-co-p-methyl styrene) elastomer as disperse phase. A low molecular weight mixture of calcium stearate and stearic acid is usually added in the dynamic vulcanization process as a lubricant, to provide smooth blown film with a uniform surface. A low viscosity slip layer is produced by two mechanisms: (a) migration of the lubricant toward the wall and (b) cross-stream migration of particles away from the wall. The objective of this paper was to study the action of lubricant in two-phase flow with the added complexity of varying rubber morphology and compare it to the action of lubricant in single phase flow of the polyamide melt. This was done by (1) evaluating the morphology both in the bulk and near the wall of extruded DVAs with varying proportions of lubricant, (2) evaluating the wall slip during extrusion of these blends in a capillary rheometer and (3) relating the morphology to the wall slip observed. Pressure dependence of viscosity was taken into account in analyzing the capillary rheometer data; furthermore Mooney plots were nonlinear for the suspensions of deformable rubber particles and this was interpreted through analysis of the particle morphology near the wall.