A solid dispersion of indomethocin in PEG 6000 was incorporated in an Eudragit matrix and compressed into tablets, each containing 35 mg of drug in controlled release dosage form. The tablets were investigated before and after acetone treatment for porosity, tortuosity and dissolution at regular intervals of 8 h. A theoretical programme is proposed to give a regulated concentration of drug in the serum. The drug dispersion in PEG 6000 was subjected to DSC analysis along with pure materials. In vivo studies in dog and human volunteers gave promising results. This paper represents a first step in a procedure which must be improved upon if it is to be useful.