Patent ID: 7112713

Claim:
A dressing impregnated with at least one bioactive agent which delivers a pharmaceutically effective amount of a dosage form of the bioactive agent to a wound site, wherein the bioactive agent is nonionic, cationic or anionic, wherein a pH difference between the dressing and the wound site based on the Teorell-Meyer theory drives delivery of the bioactive agent into the wound site; wherein the dosage form is designed by the steps of: (a) providing a pH difference between the dressing and the wound site; (b) selecting a therapeutically effective amount of the bioactive agent to be used in treatment of the wound site; (c) wherein the pH of the bandage necessary to allow an effective amount of the drug is selected according to the formula: −pH (dressing) =log[dressing]=NAX+log[wound site](t)(2.30R t ) (d) pH=pH of the dressing with the bioactive agent in place, N=the average Newtonian viscosity of the fluids of the dressing and the wound site, A=the surface area of the dressing, X=the distance the bioactive agent is to travel, T=the transport time selected, R=the universal gas constant 1.987 cal/mole-degree or 8.314 joule/mole, and log is the logarithm of the concentration of bioactive agent in the repository compartment, log is the logarithm of the concentration of drug in the wound site, t=temperature of the wound site in absolute degrees—normally 310 degrees Kelvin; (e) selecting a buffering system if needed that will provide sufficient buffering effect in the dressing to provide delivery of a therapeutic amount of the bioactive agent to the wound site by producing a pH difference between the dressing and the wound site, wherein said buffering system is capable of sustaining the pH difference in the wound site for a period of time sufficient for delivery of the metal ion to the recipient compartment; (f) admixing the therapeutically effective amount of the metal ion together with the components of the selected buffering system, a pharmaceutically appropriate base and inert ingredients, into a desired dosage form.