Ketorolac tromethamine (KT) is a non-steroidal anti-inflammatory drug having a half half-life around 6 h. This study aims to formulate sustained release forms of KT by preparing solid dispersion in the matrices of Eudragit polymers (Eud) using coevaporation technique. Tow Eud polymers, namely Eud RS100 and Eud RL100, were used in preparing KT-coprecipitates at different drug:polymer ratios. The prepared KT-Eud coprecipitates were characterized for their yield, drug content and drug in vitro release patterns as well. In addition, physicochemical characterization was carried out on some KT-Eud coprecipitates by differential scanning calorimety (DSC) and infrared spectroscopy (IR) so as to study the possibility of solid-state KT-Eud interaction. Also, KT interaction with the tested Eud polymers was carried out in solution in phosphate buffer saline (PBS, pH 7.4) along twenty days. Moreover, the analgesic activity of KT-Eud RS 100 (1: 5) coprecipitate was assessed by tail-flick method and compared to that of untreated KT. The in vitro release results indicated that the dispersions made of pure Eud RS exhibited a slower when compared to those prepared using RS/RL blends. DSC scans of KT-Eud RS 100 (1:5) systems indicated that a complete suppression of the drug fusion peaks suggesting a homogeneous dissolution of the drug in the polymer matrix. Eud RL 100 had a greater adsorptive capacity than Eud RS 100 due to the greater number of quaternary ammonium functions on RL surfaces. The maximum analgesic activity of KT-Eud RS100 (1:5) coprecipitate was between 5 and 6 h extended to 10 h while the maximum analgesic activity of untreated Ketorolac was between 2 and 2.5 h.