The present invention includes controlled release dosage forms and methods of designing and manufacturing dosage forms to obtain specific release profiles, for example, zero-order release profiles, escalating release profiles or decreasing release profiles. The dosage forms of the present invention can include spatial variation of API concentration in the dosage form and can include nested regions. Dosage forms according to the present invention may be manufactured by any appropriate method for obtaining the internal structure as disclosed herein for producing zero-order release profiles and increasing or decreasing release profiles. The invention further includes methods of manufacturing such dosage forms, such as by three-dimensional printing, possibly also including compression of the dosage form after three-dimensional printing. The invention further includes methods of designing such dosage forms. Release profiles from non-uniform distributions of API concentration may be predicted based on simple experiments with uniform-concentration dosage forms.