Calcium polycarbophil controlled release composition and method

A method of controlled release treatment comprising the steps of:

• (a) providing a polymeric complex and a therapeutically effective amount of an active agent contained within said complex, said polymeric complex comprising a reaction complex formed by the reaction of (1) a water-swellable, but water-insoluble, fibrous cross-linked carboxy-functional polymer, said polymer containing (a) a plurality of repeating units of which at least about 80 percent contain at least one carboxyl functionality and (b) about 0.05 to about 1.5 percent cross linking agent substantially free from polyalkenyl polyether, said percentages being based upon the weights of the unpolymerized repeating unit and cross-linking agent, respectively, or a salt thereof, with (2) water, said interaction being performed in the presence of an active agent, selected from the group consisting of medicinal agents, wherein the amount of calcium polycarbophil present is from about 0.1 to about 99 percent, the amount of active agent present is from about 0.0001 to about 65 percent, by weight, based upon the weight of the composition, and the amount of water present is from about 5 to about 200 percent, based upon the weight of calcium polycarbophil, said interaction being at a pH from about 3 to about 10, and the calcium polycarbophil being originally present, prior to said interaction, in the form of the calcium salt, having a calcium content from about 5 to about 25 percent, based on the weight of the polycarbophil;
• and
• (b) contacting an area of skin or mucous membrane to be treated with said composition for a period of time that is sufficient to allow a therapeutically effective amount of said active agent to be released from the complex.