A filter for mimicking regional lung deposition is provided that includes filter layers of fibrous filter material stacked coaxially and an outer ring portion encircling the fibrous filter material and securing the filter layers together. The fibrous filter material is formed for fibers having a fiber diameter, and the filter has a tunable filter efficiency. A regional lung deposition system capable of measuring constant flow or variable flow is provided that includes a throat simulation device, a filter housing downstream of and in fluid communication with the throat simulation device, a breath simulator downstream of and in fluid communication with the filter housing, and a an above-referenced filter positioned within the filter housing. Also provided is a filter housing for use in the regional lung deposition system that includes a conical housing having a small inner diameter at a first end and a large inner diameter at a second end.
