The disclosed invention is drawn to pharmaceutical tablets that provide delivery of active agents having at least three oxygen-containing groups, a tri-oxy active agent, as well as a second active ingredient. Non-limiting examples of three oxygen-containing group active agents include guaifenesin, codeine, hydrocodone, and their pharmaceutically acceptable salts. In one embodiment, a pharmaceutical tablet for oral administration once every 12 hours is provided. The tablet includes a first active agent that is a tri-oxy active agent, a second active agent, and a release rate controlling non-ionic oxyl-containing hydrophilic polymer. The total oxyl content of the hydrophilic polymer in the tablet is from about 4×10−4 moles to about 2.0×10−3 moles. The tablet is a matrix tablet and a single-dose administration of one or more tablets to a subject under fasted conditions provides a mean Cmax for each of the first active agent and the second active agent that is 70% to 135% of a respective mean Cmax provided by administering an immediate release oral dosage form to a subject under fasted conditions every 4 to 6 hours over a 12 hour time period, wherein cumulative dosage amounts administered over the 12 hour time period of each active agent is equivalent to the respective amount of each active agent in the pharmaceutical tablet.